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Remote Sensing and Hydrology

Edited by Christopher M. U. Neale & Michael H. Cosh

IAHS Publ. 352 (2012) ISBN 978-1-907161-27-8, 482 + xvi pp. Price £97.00

Remote sensing continues to expand the ability of scientists to study hydrological

processes. With each new technological development, more of the hydrological

cycle is revealed. This impacts both the scientific understanding of hydrological

processes and the models used for forecasting, and so the ability to improve

decision-making processes and other applications is increasing. This compendium

of more than 100 papers, an outcome of the latest ICRS International Symposium

on Remote Sensing and Hydrology (Jackson Hole, Wyoming, USA, Sept 2010),

reviews the status of technologies and highlights new directions and opportunities

for hydrological remote sensing.

__________________________________________________________________________________________

Preface

Remote sensing is expanding the ability of scientists to study hydrological processes. With each new technological development, more of the hydrological cycle is revealed. This impacts both the scientific understanding of hydrological processes and of the models used for forecasting. In addition, the ability to improve decision-making processes and other applications are increasing. It is appropriate at this time to review the status of technologies and determine new directions and opportunities for the next step in hydrological remote sensing. Satellite, aircraft and ground-based systems are the dominant platforms for remote sensing, from the largest to smallest spatial and temporal resolution. Frequently, a remote sensing technology is begun with a ground-based system and migrated up the platform hierarchy as its utility is demonstrated and proven to be feasible. Ultimate satellite platforms that have developed in this way include those for soil moisture, which graduated from tower- and truck-based sensors to aircraft and eventually satellite instruments, such as NASA’s AMSR-E and ESA’s SMOS. Another method of remote sensing advancement is the co-opting of a system for an additional purpose. NASA’s GRACE satellite constellation was primarily a gravity measurement mission, but it was quickly realized that it could also measure water storage anomalies over land, which are equated to groundwater change. The next generations of satellite missions are likely in development now, as either ground or aircraft based sensors, or they are being designed in the imaginations of scientists and engineers. Among the hydrological parameters being estimated by remote sensing are soil moisture, evapotranspiration, surface temperature, vegetation distribution and characteristics, snow-pack properties as well as mapping of invasive species that compete for water resources. A combination of satellite and airborne instruments have been used to retrieve these hydrological parameters that, when coupled with new techniques such as airborne and ground-based Lidar, and recently developed methods of surface energy balance flux measurements such as scintillometers and eddy covariance systems, have resulted in the advancement of applications and modelling of the hydrological cycle. These topic areas and the applications that integrate them into decision systems and models were among the sessions included in the program for the Remote Sensing and Hydrology Symposium, in Jackson Hole, Wyoming, 27–30 September 2010. This conference was organized by the International Commission on Remote Sensing of IAHS. The Symposium was attended by over 180 people including 48 students, and there were 152 oral presentations and 51 poster presentations. The key note presentations were given by Dr Christa Peters-Lidard, Branch Head, Hydrological Sciences Research, NASA Goddard Space Flight Center, and Dr Massimo Menenti, Professor and Chair of Optical and Laser Remote Sensing, Faculty of Aerospace Engineering, Delft University of Technology, The Netherlands. The oral paper presentations were distributed in three concurrent sessions with 20 minute slots. Session topics included: Data Assimilation, Surface Energy Balance and Evapotranspiration Modelling, New Satellite Missions, General Applications, Model Validation Issues using Surface Flux Measurements, GIS Applications, Scintillometry, Lidar Applications, Monitoring Invasive Species, Flood Forecasting and Management, Microwave Applications, Advances in Thermal Infrared Remote Sensing, Soil Moisture Algorithms, Application of Vegetation Indices for Evapotranspiration Modeling, Glaciers and Snow, and Irrigation Water Management. This IAHS Red Book is a compendium of papers presented at the Remote Sensing and

Hydrology Symposium. The papers were reviewed by an English editor and by peers for technical content and are grouped following the session topics at the Symposium.

Editors Christopher M. U. Neale

Department of Civil and Environmental Engineering Utah State University, Logan, Utah, USA

Michael H. Cosh USDA-ARS Hydrology and Remote Sensing Laboratory

Beltsville, Maryland, USA

The Symposium Chair was Dr Christopher M. U. Neale, VP of ICRS and Professor in the Department of Civil and Environmental Engineering, Utah State University. The technical committee included:

William P. Kustas (USDA-ARS) Richard de Jeu (VU University Amsterdam) Christopher M.U. Neale (Utah State University) Thomas Jackson (USDA-ARS) Wade T. Crow (USDA-ARS) Martha Anderson (USDA-ARS) Hendrik A. R. de Bruin (Scintec) Christopher Hopkinson (Nova Scotia Community College) John H. Prueger (USDA-ARS) Michael H. Cosh (USDA-ARS) Yangbo Chen (Sun Yat-Sen University, China) Joseph G. Alfieri (USDA-ARS)

Organizing Committee at Utah State University:

Christopher Neale Saleh Taghvaeian Robert Gerber

Symposium webpage: http://www.remotesensinghydrology.org/ International Commission on Remote Sensing of IAHS, 2007–2011:

Ian David Cluckie, ICRS President Alain Pietroniro, ICRS Past-President Frédérique Seyler, ICRS Vice-President Claude Duguay, ICRS Vice-President Christopher Neale, ICRS Vice-President Yangbo Chen, ICRS Secretary

Contents Preface by Christopher M. U. Neale and Michael H. Cosh v

1 REMOTE SENSING DEVELOPMENT

Soil moisture algorithms and retrieval

Assessment of soil moisture retrieval with numerical weather prediction model temperatures Thomas R. H. Holmes, Wade T. Crow, Thomas J. Jackson, Richard A. M. de Jeu, Rolf H. Reichle & Michael H. Cosh

3

Soil moisture retrieval using multi-channel passive microwave measurements through improved radiative transfer modelling Alok K. Sahoo, Ming Pan & Eric F. Wood

7

Near-surface soil moisture estimation using AMSR-E brightness temperature D. Al-Shrafany, D. Han & M. A. Rico-Ramirez

11

Improving satellite soil moisture estimates by combining passive and active microwave observations (1992–2008) Yi Liu, Robert Parinussa, Wouter Dorigo, Richard de Jeu, Wolfgang Wagner, Matthew McCabe, Jason Evans & Albert van Dijk

16

SMOS soil moisture validation with dense networks: preliminary results Thomas. J. Jackson, Rajat Bindlish, Michael H. Cosh & Tanjie Zhao

21

Evaluation of SMOS soil moisture with other existing satellite products Richard de Jeu, Thomas Holmes, Wolfgang Wagner, Wouter Dorigo, Sebastian Hahn & Robert Parinussa

25

Evaluating remotely-sensed surface soil moisture estimates using triple collocation Wade T. Crow, Michael H. Cosh & Diego G. Miralles

29

Using agricultural in situ soil moisture networks to validate satellite estimates Michael H. Cosh, John Prueger & Thomas J. Jackson

34

Validation of the soil moisture measurement algorithm of AMSR-E Icirow Kaihotsu, Toshio Koike, Hideyuki Fujii, Tsutomu Yamanaka, Oyunbaatar Dambaravjaa, Azzaya Dorgorsuren & Kazuaki Shiraishi

38

Towards a better monitoring of soil moisture using a combination of estimates from passive microwave and thermal observations Zulamet Vega-Martínez, Marouane Temimi, Martha C. Anderson, Christopher Hain, Nir Krakauer, Robert Rabin & Reza Khanbilvardi

42

Using global land surface emissivity as soil moisture indicator H. Norouzi, M. Temimi & R. Khanbilvardi

46

Advances in thermal-infrared remote sensing

Field thermal infrared emissivity dependence on soil moisture Juan M. Sánchez, Andrew N. French, Maria Mira, Douglas Hunsaker, Kelly Thorp, Enric Valor & Vicente Caselles

50

Monitoring the dynamic geohydrology of the Upper Geyser Basin, Yellowstone National Park: an integration of airborne thermal infrared and LiDAR Imagery C. Jaworowski, H. P. Heasler, C. M. U. Neale , S. Sivarajan & A. Masih

54

Estimation of surface energy fluxes in vineyard using field measurements of canopy and soil temperature M. P. González-Dugo, J. González-Piqueras, I. Campos, C. Balbontín & A. Calera

59

Glaciers and snow

Effectiveness of four water-bearing zones of the glacierized basin in meltwater runoff modelling Umesh K. Haritashya

63

Snow cover and stream discharge in the Wind River Range, Wyoming, USA, 1970–2009 Dorothy K. Hall, James L. Foster, Nicolo E. Digirolamo, Jonathan S. Barton & George A. Riggs

67

2 SURFACE HEAT FLUXES

Surface energy balance / ET modelling

Refining components of a satellite-based surface energy balance model to complex land-use systems Richard G. Allen, Jeppe H. Kjaersgaard, Ricardo Trezza, A. Oliveira, C. Robison & I. Lorite-Torres

73

Long-term global evapotranspiration from remote sensing Raghuveer K. Vinukollu, Alok Sahoo, Justin Sheffield & Eric F. Wood

76

ET estimation for olive orchards using satellite-based energy balance and ET simulation Cristina Santos, Ignacio J. Lorite, Masahiro Tasumi & Richard G. Allen

80

Seasonal evapotranspiration mapping using Landsat visible and thermal data with an energy balance approach in central Nebraska Ayse Irmak, I. Ratcliffe, P. Ranade, J. S. Irmak, R. G. Allen, J. Kjaersgaard, B. Kamble, R. Choragudi, K. G. Hubbard, R. Singh, D. Mutiibwa & N. Healey

84

Two different remote sensing techniques for monitoring crop coefficient and water requirement of cotton Saleh Taghvaeian, Christopher M. U. Neale, Carlos A. C. Dos Santos, Doyle Watts, John Osterberg & Subramania I. Sritharan

89

Adjusting for background soil evaporation when interpolating evapotranspiration between satellite overpass dates Jeppe Kjaersgaard, Richard Allen, Clarence Robison, Ayse Irmak, Ian Ratcliffe, Pari Ranade, Ricardo Trezza, Ramesh Dhungel & Eric Kra

94

Implementation of SEBAL algorithm with Landsat Thematic Mapper 5 in lower Colorado River Basin Xiaofang Wei, Subramania I. Sritharan, Ramani Kandiah, John Osterberg, Christopher Neale, Keith Farrow & John Davenport

98

Filling satellite image cloud gaps to create complete images of evapotranspiration Jeppe Kjaersgaard, Richard Allen, Ricardo Trezza, Clarence Robison, Aureo Oliveira, Ramesh Dhungel & Eric Kra

102

Comparison of ET from two remote sensing-based surface energy models in south central Nebraska O. Z. Akasheh, A. Irmak, S. Irmak, I. Ratcliffe, R. Singh, P. Ranade & P. H. Gowda

106

Reference crop evapotranspiration estimated from geostationary satellite imagery H. A. R. de Bruin, Isabel F. Trigo, P. Gavilan, A. Martínez-Cob & M. P. González-Dugo

111

Satellite-only latent heat flux estimation Kaniska Mallick & Andrew Jarvis 115

ETLook: a novel continental evapotranspiration algorithm H. Pelgrum, I. J. Miltenburg, M. J. M. Cheema, A. Klaasse & W. G. M. Bastiaanssen

120

Analysis of energy flux estimations over Italy using time-differencing models based on thermal remote sensing data C. Cammalleri, M. C. Anderson, G. Ciraolo, G. D’Urso, W. P. Kustas, C. Hain, L. Schultz & J. R. Mecikalski

124

Validation of the global evapotranspiration algorithm (MOD16) in two contrasting tropical land cover types Anderson L. Ruhoff, Walter Collischonn, Adriano R. Paz, Humberto R. Rocha, Luiz E. O. C. Aragao, Yadvinder Malhi, Qiaozhen Mu & Steve W. Running

128

Integration of multi-scale thermal satellite imagery for evaluation of daily evapotranspiration at sub-field scales M. C. Anderson, W. P. Kustas, W. P. Dulaney, F. Gao & D. Sumner

132

Atmospheric correction of Landsat TM imagery for evapotranspiration estimation in the lower Colorado River basin Xiaofang Wei, Subramania I. Sritharan, Andy French, David Eckhardt, Ramani Kandiah & Andre Morton

137

Applying remotely-sensed energy balance models in Iran: potentials and limitations Samaneh Poormohammadi, Mohammad H. Rahimian & Saleh Taghvaeian

141

Utility of the thermal-based Dual-Temperature-Difference technique under strongly advective conditions during BEAREX08 William P. Kustas, Joseph G. Alfieri, Martha C. Anderson, Paul D. Colaizzi, John H. Prueger, Jose L. Chavez, Christopher M. U. Neale, Wayne Dulaney, Steven R. Evett, Karen S. Copeland & Terry A. Howell

145

Towards an improved mapping of evapotranspiration in semi-arid regions Mustafa Gokmen, Christiaan van der Tol, Zoltán Vekerdy, Wouter Verhoef, Okke Batelaan & Hasan Z. Sarikaya

149

Modelling evapotranspiration by remote sensing parameters and agro-meteorological stations Antonio H. de C. Teixeira

154

Modelling sensible heat flux for sparse arid natural ecosystems using multispectral video imagery Seifeldin H. Abdalla & Christopher M. U. Neale

158

Custom software application for analysing urban landscape water use Adrian P. Welsh, Christopher M. U. Neale, Joanna Endter-Wada, & Roger K. Kjelgren

162

Determination of surface resistance to evapotranspiration by remote sensing parameters in the semi-arid region of Brazil for land-use change analyses Antonio H. de C. Teixeira

167

Spatial EvapoTranspiration Modelling Interface (SETMI) Hatim M. E. Geli & Christopher M. U. Neale

171

Local and global sensitivity analysis on METRIC A. Irmak, R. Kumar & R. E. Allen 175

Scintillometry

Long path scintillometry: a brief review H. A. R. De Bruin & J. G. Evans 180

The use of large aperture scintillometer and eddy covariance system for monitoring energy and water vapour fluxes over different surfaces in the Heihe River Basin, China Shaomin Liu, Ziwei Xu & Weizhen Wang

184

Incorporating LIDAR data into scintillometer-based estimates of sensible heat flux considering different atmospheric stability conditions Hatim M. E. Geli, Christopher M. U. Neale, Doyle R. Watts, John Osterberg & Robert T. Pack

191

Estimating ET using scintillometers and satellites in an irrigated vineyard in the Costa De Hermosillo, Sonora, Mexico M. Mulder, J. A. Lopez-Ibarra, C. J. Watts, J. C. Rodriguez, O. K. Hartogensis & A. F. Moene

195

Determining sensible and latent heat fluxes at satellite grid scales by two-wavelength scintillometry J. G. Evans, D. D. McNeil, R. J. Harding & H. A. R. De Bruin

199

Model validation issues using surface flux measurements

Impact of pixel versus footprint approaches on empirically derived ET estimates from Landsat TM Lynn F. Fenstermaker, Richard L. Jasoni, Jay A. Arnone III & Dale A. Devitt

202

Ground-based riparian evapotranspiration measurements for remote sensing algorithms Ramanitharan Kandiah, Xiaofang Wei, Subramania Sritharan, Doyle Watts, Christopher Neale, John Osterberg & Sumantra Chatterjee

206

How representative is a point? The spatial variability of flux measurements across short distances Joseph G. Alfieri & Peter D. Blanken

210

A comparison of the eddy covariance and lysimetry-based measurements of the surface energy fluxes during BEAREX08 Joseph G. Alfieri, William P. Kustas, John H. Prueger, Jose L. Chavez, Steven R. Evett, Christopher M. U. Neale, Martha C. Anderson, Lawrence E. Hipps, Karen S. Copeland, Terry A. Howell, Andrew N. French, Wayne Dulaney & Lynn McKee

215

3 APPLICATIONS

General

Parameterization based on NOAA-AVHRR NDVI to improve conceptual rainfall–runoff modelling in a large West African catchment Alain Dezetter & Denis Ruelland

221

Stream–aquifer interaction assessment using riparian evapotranspiration estimates from remote sensing algorithms Subramania I. Sritharan, Pramila Khanal, Xiaofang Wei, Ramanitharan Kandiah, Mark H. Hatfield, Christopher Neale & Johns Osterberg

231

Airborne multi-sensor platform with potential for hydrological applications: demonstration of fluorescence measurements of turbidity Björn Baschek & Axel Winterscheid

235

Integrated remote sensing of bathymetry and onshore topography for asset inspection, hydrology modelling and hazard assessment Todd J. Mitchell, Gilbert Suarez & Phil Hogan

239

Evaluating the effect of uncertainty in the delineation of a watershed over the peak flow computation Luísa M. S. Gonçalves, Cidália C. Fonte & Ricardo Gomes

243

Potential impact of Sambor Dam project on Tonle Sap Lake ecosystem based on remote sensing imaging Sushu Wu, Hiroshi Ishidaira & Wenchao Sun

248

Multi-sensor remote sensing based modelling of the water balance of endorheic lakes on the Tibetan Plateau Volker Hochschild, Jan Kropacek, Sophie Biskop, Andreas Braun, Feng Chen, Manfred Fink, Joerg Helmschrot, Shichang Kang, Peter Krause, Reik Leiterer, Qinghua Ye & Wolfgang-Albert Fluegel

253

Effects of resolution and scale on the accuracy of “impervious fraction” for urban catchments in Australia Rebecca Trevithick & Bofu Yu

257

Impact of dynamic albedo and vegetation fraction on the simulation of drought in southeast Australia using a regional climate model Jason P. Evans, Matthew F. McCabe & Xianhong Meng

262

Monitoring land surface changes and water deficit of Horqin Sandy Land in a changing climate Haijing Wang, Irena Hajnsek & Wolfgang Kinzelbach

266

Sediment discharge from an agricultural watershed: investigating the influence of land-cover fragmentation using the GSSHA model Ariel C. Blanco, Kazuo Nadaoka & Ma. Cecilia R. Paringit

272

Earth Observation integrated modelling tool for description of the water balance and runoff production of the Tibetan Plateau Guido D’Urso, Walter Immerzeel, Carlo De Michele, Hongxing Zheng & Massimo Menenti

276

Sensitivity of glacial change detection on Bridge Glacier, Canada, to horizontal datum transformations Tristan Goulden, Chris Hopkinson & Micheal N. Demuth

280

Detection and feature analysis of groundwater discharge points in coastal regions around Mt Chokaisan, Japan using ALOS AVNIR-2 data Yoichi Kageyama, Chieko Shibata & Makoto Nishida

284

Remote sensing method for estimating green and blue water footprint Mireia Romaguera, Mhd Suhyb Salama, Maarten S. Krol, Zhongbo Su & Arjen Y. Hoekstra

288

Analysing parameter sensitivities in a complex distributed hydrological model using remotely sensed surface temperatures Simon Stisen & Matthew F. McCabe

292

Monitoring and modelling water quality parameters by means of hyperspectral data Asif M. Bhatti & Seigo Nasu

296

Using SPOT-VEG based vegetation indices compared with AVHRR-based vegetation indices for drought monitoring in the south of Iran Mohammad Amin Owrangi, Mehrdad Rahnamaei, Ali Mohammad Zadeh & Reza Afshin Sharifan

300

Transformations of river bed pattern of a lowland river inferred from aerial surveys and ground penetrating radar (GPR) 0DUFLQ�6áRZLN�

304

Data assimilation and GIS applications

Data assimilation for improving soil moisture estimation at hillslope scales: experiments with synthetic SMAP radar data Alejandro N. Flores, Dara Entekhabi & Rafael L. Bras

308

Data assimilation of space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction Ben T. Gouweleeuw, Albert I. J. M. van Dijk & Luigi J. Renzullo

312

Estimating the global terrestrial hydrologic cycle through modelling, remote sensing and data assimilation Ming Pan, Tara J. Troy, Alok K. Sahoo, Justin Sheffield & Eric F. Wood

316

Assimilation of remotely sensed snow cover within land surface models to support early detection of agricultural drought John Halquist, Gregory M. Fall & Dagang Wang

321

Remote sensing and GIS in inflow estimation for reservoir operations – Magat Dam, Philippines Czar Jakiri S. Sarmiento, Rhodora M. Gonzalez & Peter M. Castro

325

LiDAR applications

Using selective drainage methods to hydrologically-condition and hydrologically-enforce LiDAR-derived surface flow Sandra Poppenga, Bruce Worstell, Jason Stoker & Susan Greenlee

329

Changes in topographic context of the Yanamarey Glacier in the Tropical Peruvian Andes Kyung In Huh, Bryan G. Mark & Chris Hopkinson

333

Sensitivity of modelled evapotranspiration to canopy characteristics within the Western Boreal Plain, Alberta Laura Chasmer, Richard Petrone, Scott Brown, Chris Hopkinson, Carl Mendoza, John Diiwu, William Quinton & Kevin Devito

337

Hydrological implications of periglacial expansion in the Peyto Glacier catchment, Canadian Rockies Chris Hopkinson, Michael N. Demuth & Michael Sitar

341

Sensitivity of topographic slope and modelled watershed soil loss to DEM resolution 345

Tristan Goulden, Chris Hopkinson & Rob Jamieson

Estimation of vegetation hydrodynamic density using high density airborne laser scanning data M. Z. A. Rahman, B. Gorte & M. Menenti

350

Relationships between snowpack depth and primary LiDAR point cloud derivatives in a mountainous environment Chris Hopkinson, John Pomeroy, Chris DeBeer, Chad Ellis & Axel Anderson

354

Delineation of lakes and channels in the Mackenzie Delta, NWT, using airborne LiDAR Neville Crasto, Chris Hopkinson, Philip Marsh, Donald L. Forbes & Ian Spooner

359

Estimation of composite hydrodynamic roughness over land with high density airborne laser scanning data M. Z. A. Rahman, B. Gorte & M. Menenti

363

Microwave applications

SWEHydro Model and AMSR-E observations: an effective tool to reconstruct snowmelt runoff timing and magnitude Joan Ramage & Kathryn A. Semmens

367

Regional and temporal patterns of soil moisture during CLASIC using passive microwave satellite observations Rajat Bindlish, Thomas J. Jackson, Yongqain Wang, Jiancheng C. Shi & Jeffery Basara

371

Polarimetric change detection for wetlands A. Schmitt, B. Brisco, S. Kaya & K. Murnaghan

375

Canadian SAR remote sensing for the Terrestrial Wetland Global Change Research Network (TWGCRN) S. Kaya, B. Brisco, A. Cull, A. Gallant, W. Sadinski & D. Thompson

380

Potential for improved crop yield prediction through assimilation of satellite-derived soil moisture data I. E. Mladenova, W. T. Crow, P. Doraiswamy, W. Teng & S. Milak

384

Monitoring invasive species

Assessing the impact of Invasive Alien Plants on South African water resources using remote sensing techniques Caren Jarmain & Wouter M. L. Meijninger

388

Salt cedar biomass study in Cibola national wildlife refuge Xiaofang Wei, Subramania I. Sritharan, John Osterberg, John Davenport & Terrell Washington

393

Applications of vegetation indices for ET modelling

Basal crop coefficient from remote sensing assessment in rain-fed grapes in southeast Spain Isidro Campos, Alfonso Calera, Claudio Balbontín, Enrique A. Torres, José González-Piqueras & Christopher M. U. Neale

397

Coupling remote sensing and FAO-56 for a distributed water budget model in large areas: HidroMORE Enrique A. Torres, Alfonso Calera, Jose González-Piqueras, Eva Rubio, Isidro Campos & Claudio Balbontin

401

Estimating Palo Verde irrigation district evapotranspiration using MODIS enhanced vegetation index and micro-meteorological data Sumantra Chatterjee, Subramania Sritharan, Doyle Watts & Thaddeus Tarpey

406

Comparison of Sap Flux, Moisture Flux Tower and MODIS Enhanced Vegetation Index methods for estimating riparian evapotranspiration Pamela L. Nagler, Edward P. Glenn & Kiyomi Morino

410

Irrigation water management

Irrigation scheduling decision support for field-scale, surface irrigation using remote sensing and ground-based data Douglas Hunsaker, Andrew French, Peter Waller, Eduardo Bautista1, Patrick Royer, Kelly Thorp, Pedro Andrade-Sanchez & John Heun

414

Operational irrigation services from remote sensing: the irrigation advisory plan for the Campania Region, Italy Guido D’Urso, Carlo De Michele & Francesco Vuolo

419

Earth Observation for irrigation and river basin management in an operational way: the SPIDER system Alfonso Calera, Anna Osann, Guido D’Urso, Christopher Neale & Juan Manuel Moreno

423

The spatial and temporal variation of crop water consumption and the impact on water productivity in the Limpopo River basin Xueliang Cai, Poolad Karimi, Mutsa Masiyandima & Hilmy Sally

427

Flood forecasting and management

Remote sensing techniques as a tool for development of small scale urban runoff model Wai Yeung Yan, Ahmed Shaker, Darko Joksimovic & A. Dialame

431

SEBAL evapotranspiration estimates for the improvement of distributed hydrological model runoff and soil moisture predictions Nawa Raj Pradhan, Aaron R. Byrd, Fred L. Ogden & Jan M. H. Hendrickx

435

Estimating African daily evapotranspiration using MODIS and MSG data Zhigang Sun & Mekonnen Gebremichael

440

Threshold and parameter optimization method of the radar classified Z–I relationship and its application in flood forecasting Song Xingyuan & Luo Peng

444

The impacts of radar-precipitation-estimation on streamflow simulation with HSPF Huijun Xu, Qizhong Guo & Yangbo Chen

449

New generation flood forecasting in China: opportunity, research and challenge Yangbo Chen

454

ASAR/ENVISAT images for the calibration of the wind hydrodynamic effect on Doñana wetlands Belen Marti-Cardona, Thanh Duc Tran, Ernest Blade-Castellet & Josep Dolz-Ripolles

459

Global scale simulation of flood plain inundation with low resolution space-borne data Guy J.-P. Schumann, Jeffrey C. Neal & Paul D. Bates

464

Calibration of rainfall–runoff models based on satellite observations of river width at the basin outlet Wenchao Sun, Hiroshi Ishidaira, Satish Bastola & Sushu Wu

468

Key word index 473

17

Remote Sensing and Hydrology (Proceedings of a symposium held at Jackson Hole, Wyoming, USA, September 2010) (IAHS

Publ. 352, 2012),3-6.

Assessment of soil moisture retrieval with numerical weather prediction model temperatures THOMAS R. H. HOLMES1, WADE T. CROW1, THOMAS J. JACKSON1, RICHARD A. M. DE JEU2, ROLF H. REICHLE3 & MICHAEL H. COSH1

1 USDA-ARS Hydrology and Remote Sensing Laboratory, 10300 Baltimore Ave., Beltsville, Maryland 20705, USA [email protected]

2 Department of Hydrology and Geo-Environmental Sciences, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, Amsterdam 1082 HV, The Netherlands 3 NASA GSFC, Hydrological Science Branch, Greenbelt, Maryland 20771, USA

Abstract The effect of using a Numerical Weather Prediction (NWP) soil temperature product instead of estimates provided by concurrent 37 GHz data on satellite-based passive microwave retrieval of soil moisture was evaluated. This was prompted by the change in system configuration of preceding multi-frequency satellites to new single frequency L-band missions. In situ soil moisture data from four watershed sites in the USA were used to assess this change with one soil moisture retrieval algorithm. The temperature product substitution resulted in a large decrease in sensitivity to in situ soil moisture changes, and illustrates the complications of moving from a coincident source to interpolation of modelled temperature. Key words land surface temperature; soil moisture retrieval; WindSat; LPRM

18


Publ. 352, 2012), 7-10.

Soil moisture retrieval using multi-channel passive microwave measurements through improved radiative transfer modelling ALOK K. SAHOO, MING PAN & ERIC F. WOOD

Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, USA [email protected] Abstract This study is focused on a soil moisture retrieval system which uses a microwave emission model based on multi-channel passive microwave measurements. The retrieval system has recently been updated with better parameterizations. The notable improvements to the above system include: (i) new microwave measurement-based input surface soil moisture data, (ii) replacement of the input VWC climatology data set with monthly varying VOD data sets, (iii) implementation of a new calibration technique to calibrate the soil texture and roughness parameter, and (iv) application of rainfall, active snow, RFI and thick vegetation masks based on microwave channels. The recently improved retrieval system produces very reasonable soil moisture results. The results are very preliminary in nature, and require more rigorous quantitative analysis in order to be used for any regional to climate scale applications. Key words soil moisture; radiative transfer model; microwave satellite measurements

19


Publ. 352, 2012),11-15

Near-surface soil moisture estimation using AMSR-E brightness temperature D. AL-SHRAFANY, D. HAN & M. A. RICO-RAMIREZ

Water and Environmental Management Research Centre, Department of Civil Engineering, University of Bristol, Bristol BS8 1TR, UK [email protected] Abstract In situ measurement of soil moisture is difficult; extensive and expensive observations are required for good estimation. This is the first study that uses rainfall and runoff data with the water balance equation to calibrate the roughness parameters (h and Q) and to validate satellite soil moisture data. The methodology used the Advanced Microwave Scanning Radiometer (AMSR-E) data and the first-order radiative transfer model in order to retrieve the volumetric soil moisture (vsm). The analysis of two years of data indicates that the estimated daily surface soil moisture is well correlated with the flow observations and a good correlation (R2 = �� LV� VKRZQ� EHWZHHQ� WKH�ZDWHU� VWRUDJH� FKDQJH� �ǻV�� DQG� WKH� VRLO�PRLVWXUH� FKDQJH� �ǻș��7KH� VRLO�PRLVWXUH�estimated in this new approach would be more relevant to hydrological applications due to its linkage with the rainfall–runoff process. Key words soil moisture; AMSR-E; water balance; remote sensing

20


Publ. 352, 2012), 16-20.

Improving satellite soil moisture estimates by combining passive and active microwave observations (1992–2008) YI LIU1,2,4, ROBERT PARINUSSA2, WOUTER DORIGO3, RICHARD DE JEU2, WOLFGANG WAGNER3, MATTHEW MCCABE1, JASON EVANS5 & ALBERT VAN DIJK4

1 School of Civil and Environmental Engineering, University of New South Wales, Sydney 2052, Australia [email protected]

2 Department of Hydrology and Geo-Environmental Sciences, Faculty of Earth and Life Sciences, VU University Amsterdam, De Boelelaan 1085, Amsterdam 1081 HV, Netherlands

3 Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Gusshaustrasse 27–29, Vienna A-1040, Austria

4 Black Mountain Laboratory, CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia 5 Climate Change Research Centre, University of New South Wales, Sydney 2052, Australia

Abstract We propose a methodology to blend soil moisture retrievals from passive (SSM/I, TRMM and AMSR-E) and active (ERS and ASCAT) microwave satellite observations and obtain an improved long-term (1992–2008) global product. The first step is to merge the three passive microwave data sets into a single “passive” product and two active microwave data sets into a single “active” product. This avoids the issue of differences in sensor specifications resulting in different absolute soil moisture values. Next, both data sets are adjusted against a common reference (GLDAS-Noah), which scales both data sets to the same dynamic range and allows the generation of a blended product. The proposed approach has the potential to be applied to existing as well as new missions. Key words soil moisture; microwave; satellite observations; long term

21


Publ. 352, 2012), 21-24.

SMOS soil moisture validation with dense networks: preliminary results THOMAS. J. JACKSON, RAJAT BINDLISH, MICHAEL COSH & TANJIE ZHAO

USDA ARS Hydrology and Remote Sensing Laboratory, 10300 Baltimore Blvd, Beltsville, Maryland 20705, USA [email protected] Abstract Validation is important for passive microwave remote sensing of soil moisture from earth orbit. Soil moisture products from the recently launched Soil Moisture Ocean Salinity (SMOS) satellite are evaluated here using data from the first few months following launch. Soil moisture estimates are compared to data from a set of dense in situ soil moisture observing networks distributed across the USA, each of which approximates the size of a SMOS footprint. In situ data from these sites have been calibrated and verified through field campaigns and applied to validating other satellite products. Results show that the SMOS products are reasonable at this stage of validation; however, there are indications that improvements can be made through a careful review of the in situ and alternative satellite product comparisons. Key words soil moisture; validation; SMOS; AMSR-E

22


Publ. 352, 2012), 25-28.

Evaluation of SMOS soil moisture with other existing satellite products RICHARD DE JEU1, THOMAS HOLMES2, WOLFGANG WAGNER3, WOUTER DORIGO3, SEBASTIAN HAHN3 & ROBERT PARINUSSA2

1 Department of Hydrology and Geo-Environmental Sciences, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam 1081 HV, Netherlands [email protected]

2 Hydrology and Remote Sensing Laboratory, Agricultural Research Service, US Department of Agriculture, Beltsville, Maryland 20705, USA

3 Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Gusshaustrasse 27-29, Vienna A-1040, Austria Abstract The quality of one of the first available level 2 soil moisture datasets from ESA’s Soil Moisture and Ocean Salinity Mission (SMOS) is evaluated. Global soil moisture retrievals are compared with two other soil moisture products; AMSR-E soil moisture, and Metop-ASCAT soil moisture. A correspondence analysis is applied to compare the spatial patterns. From this first analysis we see dissimilarities between SMOS and the other two products, particularly over northern latitude regions and more densely vegetated areas. In the northern latitudes regions SMOS L2 produces soil moisture in a small range with relatively low soil moisture values. The actual reason for this mismatch is still unknown, but it might be related to the use of ancillary datasets within the SMOS algorithm. Such an approach might introduce artificial spatial features in the soil moisture product. However, it is also known that the other two sets do have a limited performance over the densely vegetated regions. Further research using independent datasets is needed to better characterise the retrieval errors of SMOS and the other two satellite products. Key words soil moisture; SMOS, microwave remote sensing; satellite observations

23


Publ. 352, 2012), 29-33

Evaluating remotely-sensed surface soil moisture estimates using triple collocation WADE T. CROW1, MICHAEL H. COSH1 & DIEGO G. MIRALLES2

1 USDA ARS Hydrology and Remote Sensing Laboratory, Rm. 104, Blg. 007, BARC-W, Beltsville, Maryland 20705, USA [email protected]

2 The Department Of Hydrology and GeoEnvironmental Sciences, VU Amsterdam, De Boelelaan 1085, 1081HV Amsterdam, The Netherlands Abstract Recent work has demonstrated the potential of enhancing remotely-sensed surface soil moisture validation activities through the application of triple collocation (TC) techniques which compare a time series of three mutually independent soil moisture estimates in order to acquire the root-mean-square error of each estimate individually. Using soil moisture estimates acquired from land surface modelling, passive microwave remote sensing and active microwave remote sensing alongside independent ground observations obtained within four intensively-instrumented watersheds, this paper independently verifies a soil moisture TC analysis. Results demonstrate the potential of the approach for validating remotely-sensed soil moisture products and identify a possible source of bias associated with cross-correlated errors in the remotely-sensed soil moisture products. Key words soil moisture; remote sensing; triple collocation; ground validation

24


Publ. 352, 2012), 34-37.

Using agricultural in situ soil moisture networks to validate satellite estimates MICHAEL H. COSH1, JOHN PRUEGER2 & THOMAS J. JACKSON1

1 USDA-ARS Hydrology and Remote Sensing Laboratory, Beltsville, Maryland 20705, USA [email protected]

2 USDA-ARS National Laboratory for Agriculture and the Environment, Ames, Iowa 50011, USA Abstract The validation of soil moisture remote sensing products is generally based upon in situ networks which are often in non-representative locations. Soil moisture sensors have, until recently, been added to existing precipitation networks, which are not installed inside agricultural fields. An initial attempt at a realistic agricultural network has been developed in the Walnut Creek watershed near Ames, Iowa. Small temporary soil moisture stations are installed within the corn and soybean fields which dominate the region. This network design results in a non-continuous but representative watershed average during active growing seasons. Begun in 2006, nine stations have been recording the surface soil moisture (~5 cm). A stable and reliable network can be achieved with repeated installation procedures which will be useful for monitoring in situ watersheds dominated by agriculture. Key words soil moisture; satellite validation; network design; agriculture; Iowa

25


Publ. 352, 2012), 38-41.

Validation of the soil moisture measurement algorithm of AMSR-E ICIROW KAIHOTSU1, TOSHIO KOIKE2, HIDEYUKI FUJII3, TSUTOMU YAMANAKA4, OYUNBAATAR DAMBARAVJAA5, AZZAYA DORGORSUREN5 & KAZUAKI SHIRAISHI6

1 Department of Natural Environmental Sciences, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan [email protected]

2 Department of Civil Engineering, The University of Tokyo, Tokyo 113-8656, Japan 3 Earth Observation Center, JAXA, Tsukuba 305-8505, Japan

4 Terrestrial Environment Research Center, University of Tsukuba, Tsukuba 305-8577, Japan 5 Institute of Meteorology and Hydrology, Ulaanbaatar-46, Mongolia 6 Graduate School of Integrated Arts and Sciences, Hiroshima University 739-8521, Japan

Abstract It is essential for AMSR-E soil moisture observation to precisely validate the measurement algorithm. We installed in situ water cycle stations with the TDR probes for monitoring soil moisture, and several sensors in the MAVEX (Mongol AMSR/AMSR-E/AMSR2 Validation Experiment) study area that is covered with pasture and shrubs, in the eastern part of the Mongolian Plateau for the validation. We attempted to validate the latest algorithm (Koike Ver. 5.34) of soil moisture measurement of AMSR-E using the in situ station monitoring data in the MAVEX study area from 2002 to 2009. Although the algorithm overestimated soil moisture slightly, a good correlation was found between the AMSR-E soil moisture estimation and the in situ soil moisture in the MAVEX study area. The AMSR-E soil moisture observation can be considered to be fundamentally effective and useful to estimate surface soil moisture over large areas of the bare and grass lands. Key words soil moisture; AMSR-E; TDR; Mongolian Plateau

26


Publ. 352, 2012), 42-45.

Towards a better monitoring of soil moisture using a combination of estimates from passive microwave and thermal observations ZULAMET VEGA-MARTÍNEZ1, MAROUANE TEMIMI1, MARTHA C. ANDERSON2, CHRISTOPHER HAIN3, NIR KRAKAUER1, ROBERT RABIN4 & REZA KHANBILVARDI1

1 NOAA-CREST, City University of New York, New York, New York 10031, USA [email protected]

2 USDA-ARS-Hydrology and Remote Sensing Lab, Beltsville, Maryland 20705, USA 3 NOAA-NESDIS, Camp Springs, Maryland 20746 USA 4 NOAA/NSSL, Madison, Wisconsin 53706 USA

Abstract Soil moisture is a key variable in hydrological and meteorological processes. It exhibits significant temporal and spatial variation. Therefore, the use of satellite imagery to monitor its variability is crucial. The main objective of this work is to implement a multi-satellite approach which combines soil moisture estimates from passive microwave and thermal observations to improve the monitoring of soil wetness on a continental scale. Soil moisture estimates are obtained from passive microwave data from the AMSR-E NASA product and from thermal and near infrared observations using the ALEXI model. Ultimately, a statistical combination of these two products would overcome their individual limitations, allowing for better monitoring of soil moisture. The main limitation of passive microwave-based products is their coarse spatial resolution. Their main advantage, however, is their capability to penetrate clouds. On the other hand, the main advantage of the ALEXI-based product is its higher spatial resolution and deeper sampling into the root zone. Cloud blockage is its main limitation. The prospective product, the result of the combination, would have a better spatial resolution than the passive microwave-based product and a better temporal coverage than the ALEXI-based product. Several locations with different land cover conditions were chosen to compare and analyse the difference between the two products. These areas are located in Washington State, California, Texas, Alabama, Florida and New York, USA. The Atmosphere-Land Exchange (ALEXI) model mainly uses GOES data to calculate soil moisture in clear-sky days on a continental scale. On cloudy days, when visual imagery is affected by clouds, a gap-filling technique is adopted to continue inferring soil moisture. A preliminary visualization of the soil moisture products from ALEXI and AMSR-E has been conducted, including daily evaluations for the different combinations of data in different regions. A reasonable agreement has been noticed between the two products. The consistency between the two products suggests that they can be combined for better monitoring of soil wetness. Key words ALEXI; soil moisture; AMSR-E; evapotranspiration; passive microwave

mailto:[email protected]

27


Publ. 352, 2012),46-49.

Using global land surface emissivity as soil moisture indicator H. NOROUZI, M. TEMIMI & R. KHANBILVARDI

The City College of The City University of New York, New York, New York 10075-0711, USA/ NOAA-Cooperative Remote Sensing Science and Technology Center (CREST) [email protected] Abstract Soil moisture is one of the most uncertain variables in hydrologic models, especially in large watersheds. Direct measurement of this parameter at these large scales is not straightforward. The main objective of this work is to demonstrate the potential of using land microwave emissivity as a surrogate for soil moisture. First, an instantaneous global microwave land emissivity product has been developed using AMSR-E observations. This retrieval utilizes all AMSR-E frequencies and infrared-based data for physical skin temperature. Data sets provided by the International Satellite Cloud Climatology Project (ISCCP) were used. Moreover, information on water vapour and air temperature obtained from the ISCCP database (TOVS data) was used to calculate the upwelling and downwelling atmospheric brightness temperatures, as well as the atmospheric transmission. A monthly composited map was developed for each frequency. The analysis of the obtained maps has shown an acceptable agreement with the global pattern of land use/land cover. The difference between V and H polarization, as well as the difference between day and night in emissivity retrievals, showed an acceptable consistency with soil moisture. Fraction of surface water was developed in global scale using land surface emissivity with reasonable agreement with soil moisture except in highly vegetated area. Key words passive microwave; land surface emissivity; soil moisture; fraction of water surface

28


Publ. 352, 2012),50-53.

Field thermal infrared emissivity dependence on soil moisture JUAN M. SÁNCHEZ1, ANDREW N. FRENCH2, MARIA MIRA3, DOUGLAS HUNSAKER2, KELLY THORP2, ENRIC VALOR3 & VICENTE CASELLES3

1 Applied Physics Department, University of Castilla-La Mancha, Av. España s/n, 02071 Albacete, Spain [email protected]

2 US Arid Land Agricultural Research Center, USDA/ARS, 21881 N. Cardon Lane, Maricopa, Arizona 85138, USA 3 Earth Physics and Thermodynamics Department, University of Valencia, Dr. Moliner 50, 46100 Burjassot, Spain

Abstract Emissivity dependence on soil water content has been already reported and modelled under controlled conditions in the laboratory. This study completes and extends that previous work by providing emissivity measurements under field conditions without elimination of impurities, local heterogeneities or soil cracks appearing in the drying process. A bare soil plot was selected in central Arizona, USA. The soil plot was flood irrigated every 2–3 days and left to dry. Field emissivity measurements were collected for different values of soil water content. An overall increase of emissivity with soil moisture was obtained. It was also shown that deterioration of the soil surface tends to reduce the emissivity spectral contrast. Relationships obtained by Mira et al. (2010) were tested and compared with the field measurements. Key words thermal infrared emissivity; soil moisture; soil cracks; Maricopa, Arizona, USA

29


Publ. 352, 2012), 54-58.

Monitoring the dynamic geohydrology of the Upper Geyser Basin, Yellowstone National Park: an integration of airborne thermal infrared and LiDAR Imagery C. JAWOROWSKI1, H. P. HEASLER1, C. M. U. NEALE2, S. SIVARAJAN2 & A. MASIH2

1 Yellowstone Center for Resources, Yellowstone National Park, Wyoming 82190, USA [email protected]

2 Remote Sensing Services Laboratory, Civil and Environmental Engineering Dept, Utah State University, Logan, Utah 84322-4105, USA Abstract Thermal infrared images (2007–2009) rectified to a geodetic-grade LiDAR base map provide snapshots-in-time of the dynamic geohydrology within Yellowstone’s Upper Geyser Basin. Between 2007 and 2009, the Old Faithful thermal group shows little change in the spatial distribution of calculated ground temperature. Within the Biscuit Basin thermal group, temporal changes in the spatial distribution of ground temperatures may reflect changing heat and fluid flow along northwest-trending fractures, faults, and other permeable pathways. In Biscuit Basin, numerous hydrothermal explosions or forceful, geyser eruptions have been observed from 2006 through 2011. Key words LiDAR; geohydrology; thermal imagery; infrared

30


Publ. 352, 2012), 59-62

Estimation of surface energy fluxes in vineyard using field measurements of canopy and soil temperature M. P. GONZÁLEZ-DUGO1, J. GONZÁLEZ-PIQUERAS2, I. CAMPOS2, C. BALBONTÍN2 & A. CALERA2

1 IFAPA, Consejería de Agricultura, Pesca y Medio Ambiente, Junta de Andalucía, Avd. Menéndez Pidal s/n, PO Box 3048, Córdoba 14070, Spain [email protected]

2 Instituto Desarrollo Regional (IDR), Grupo de Teledetección y SIG. Universidad de Castilla-La Mancha, Campus Universitario, Albacete 02071, Spain Abstract A two-source energy balance model (TSM) has been applied over a drip-irrigated vineyard using soil and canopy radiometric temperature measured during the summer of 2007 in Central Spain. Flux estimations from the model compared well with semi-hourly and daytime values obtained by an eddy covariance flux tower installed at the same location during the experiment. The results support the ability of the two-source model to simulate the partitioning of surface energy fluxes under the low vegetation cover and semi-arid conditions of the experiment. However, the separation of crop transpiration and soil evaporation was unrealistic using the original model parameterization. Under water scarce conditions this is key information to assess the beneficial and non-beneficial fractions of the water applied to crop. For that reason, a complementary analysis to provide new insights into the application of the TSM under these specific conditions is proposed and the initial results are presented. Key words vineyard; evapotranspiration; crop and soil temperature; energy balance model; TSEB model

31


Publ. 352, 2012), 63-66

Effectiveness of four water-bearing zones of the glacierized basin in meltwater runoff modelling UMESH K. HARITASHYA

Department of Geology, University of Dayton, Dayton, Ohio 45469-2364 USA [email protected] Abstract Meltwater runoff modelling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modelling as separate entities because they behave differently and cannot be aggregated into a uniform body. Key words glacier; dry snow; wet snow; meltwater runoff modelling; temperature index; Himalaya


32


Publ. 352, 2012), 66-70.

Snow cover and stream discharge in the Wind River Range, Wyoming, USA, 1970–2009 DOROTHY K. HALL1, JAMES L. FOSTER1, NICOLO E. DIGIROLAMO2, JONATHAN S. BARTON3 & GEORGE A. RIGGS2

1 Laboratory for Hydrospheric and Biospheric Processes, NASA Goddard Space Flight Center, Greenbelt 20771, Maryland, USA [email protected]

2 SSAI, Lanham 20706, Maryland, USA 3 UMBC-GEST, Baltimore 21250, Maryland, USA

Abstract Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover maps and 40 years of stream discharge and meteorological station data are studied along with 30 years of snow-water equivalent (SWE) SNOw TELemetry (SNOTEL) data in the Wind River Range (WRR), Wyoming. We found stream discharge to be lower, with earlier snowmelt onset in the decade of the 2000s as compared to the previous three decades, though no trend of either lower streamflow or earlier snowmelt was detected within the decade of the 2000s. SWE on 1 April does not show an expected downward trend since ~1980. The extent of snow cover derived from the lowest-elevation zone of the WRR study area is strongly correlated with maximum-monthly discharge on 1 May, where r = 0.91 for the decade of the 2000s. Changes in streamflow may be related to increasing air temperatures during the 40-year study period, possibly contributing to a reduction in snow cover. Key words Wind River Range, USA; MODIS; seasonal snow cover; streamflow

33


Publ. 352, 2012), 73-75.

Refining components of a satellite-based surface energy balance model to complex land-use systems RICHARD G. ALLEN1, JEPPE H. KJAERSGAARD1, RICARDO TREZZA1, A. OLIVEIRA2, C. ROBISON1& I. LORITE-TORRES3

1 University of Idaho – Kimberly Research and Extension Center Kimberly, Idaho 83341, USA [email protected] 2 University of Bahia, Brazil 3 IFAPA, Cordoba, Spain

Abstract The METRIC model (Mapping Evapotranspiration at high Resolution using Internalized Calibration) utilizes multi-band reflectance and variation in thermal emission from Landsat and other satellites to estimate evapotranspiration (ET) using a full surface energy balance. Because of the aerodynamic nature of sensible heat exchange, aerodynamic roughness must be tailored for complex terrain and sparse systems such as trees. Soil heat flux is adjusted for hot desert conditions to account for delamination of soil layers. Net radiation is computed in mountainous areas by considering impacts of cross-valley thermal emission differences related to aspect as well as view-angle of sky and terrain. Key words evapotranspiration; METRIC; mountains; energy balance

34


Publ. 352, 2012), 76-79.

Long-term global evapotranspiration from remote sensing RAGHUVEER K. VINUKOLLU1, ALOK SAHOO2, JUSTIN SHEFFIELD2 & ERIC F. WOOD2

1 Swiss Re, 175 King Street,Armonk, New York, USA 2 Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA

Abstract Deriving overland evapotranspiration (ET) estimates is an important part of the larger effort to develop long-term Earth System Data Records (ESDRs) for the major components (storages and fluxes) of the terrestrial water cycle. In the current study, global estimates of sensible heat and evaporative fluxes are developed for 1984–2006 using three process-based models forced by two remote sensing based data sets. The models are surface energy balance system (SEBS), a modified Penman-Monteith approach, and a Priestley-Taylor approach. The models are driven by radiation inputs from the ISCCP and SRB data sets, with the meteorological forcing data from ISCCP, and vegetation characteristics from AVHRR. Estimates are made using the three models. Comparisons among the data sets show large differences in magnitude and long-term variability, due mainly to uncertainties in the forcing radiation. Comparisons with independent data sets from inferred evaporation estimates [(P-Q)climatology], off-line land surface model (VIC) data, previously developed remote sensing products and estimates derived from tower data, reveals consistency at large scales, but large differences in some regions, most notably in the northern hemisphere. Key words evapotranspiration; LandFlux; surface energy balance; Penman-Monteith; Priestley-Taylor; latent heat flux; sensible heat flux

35


Publ. 352, 2012), 80-83.

ET estimation for olive orchards using satellite-based energy balance and ET simulation CRISTINA SANTOS1, IGNACIO J. LORITE1, MASAHIRO TASUMI2 & RICHARD G. ALLEN3

1 IFAPA. Centro “Alameda del Obispo”, Alameda del Obispo s/n, PO Box 3092, Córdoba 14080, Spain [email protected]

2 Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan 3 Water Resources Engineering, University of Idaho, 3793 N. 3600 E., Kimberly, Idaho 83341, USA

Abstract Evapotranspiration (ET) from olive fields located in Andalusia, Spain, was evaluated using the METRIC satellite-based energy balance method. The model was compared against FAO 56-based ET estimations from non-irrigated olive fields where rainfall was known. The first comparisons suggested some over-estimations of ET by METRIC as it used a general equation for momentum roughness length (zom) based on a fixed function of height. The Perrier function and improved olive heights were used in METRIC for the determination of improved zom. This approach provided good results when compared to ET estimates based on FAO 56 for rainfed olive orchards (RMSE = 0.25 mm/d). Key words rainfed olive; evapotranspiration; FAO 56 model; METRIC; momentum roughness length; Perrier function

36


Publ. 352, 2012), 84-88.

Seasonal evapotranspiration mapping using Landsat visible and thermal data with an energy balance approach in central Nebraska AYSE IRMAK1, I. RATCLIFFE1, P. RANADE1, J. S. IRMAK3, R. G. ALLEN2, J. KJAERSGAARD2, B. KAMBLE1, R. CHORAGUDI1, K. G. HUBBARD1, R. SINGH4, D. MUTIIBWA3 & N. HEALEY1

1 School of Natural Resources and Civil Eng. University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA [email protected]

2 Kimberly R&E Center, University of Idaho, 3793 N 3600 E, Kimberly, Idaho 83341, USA 3 Biological Systems Engineering. University of Nebraska-Lincoln, 3310 Holdrege Street, Lincoln, Nebraska 68583, USA 4 US Geological Survey, Earth Resources Observation and Science Center, Sioux Falls, South Dakota 57198, USA

Abstract Accurate estimation of evapotranspiration (ET) plays an important role in quantification of the water balance at the watershed, basin and regional scales for better planning and managing water resources. Knowledge of spatio-temporal distribution of ET on large scales, as quantified by satellite remote sensing techniques, can provide important information on a variety of water resources issues such as evaluating water distributions, water use by different land surfaces, water allocations, water rights, consumptive water use and planning, and better management of groundwater and surface water resources. While field measurements of evapotranspiration can provide vital data for a variety of purposes, point measurements need to be scaled up to larger areas to make water resources assessments on a watershed, district, or regional scale. Furthermore, ET is highly variable in space and time due to variability in land use, climatic conditions, soil properties, and management practices. Spatial variation in soil properties affects soil evaporation and surface energy balances, causing within-field and across field variability in ET. Satellite/remote sensing technology provides an opportunity for representing spatial and temporal variation of ET. Thus, this advanced technique provides the spatial distribution of actual ET and consumptive water use over different land surfaces. This has enabled the estimation of ET from individual fields and this can enable policy makers to better understand and address the issue of water allocation and identifying and quantifying beneficial and unbeneficial water use that will result in better understanding and management of limited water resources. We applied the Mapping Evapotranspiration at High Resolution with Internal Calibration (METRICTM) to obtain ET maps for Central Platte Natural Resources District (CPNRD) in Nebraska, USA. A total of 45 images from Landsat 5 and Landsat 7 for paths 29–0 and rows 31–32 were processed for the 2007 growing season to obtain instantaneous and daily ET. In order to produce monthly and seasonal ET maps, individual daily ET maps generated from METRICTM were interpolated between dates on a daily basis using a cubic-spline model. Cloud artefacts were removed and filled back in using interpolated ET data, and a background evaporation adjustment based on the FAO-56 Ke evaporation model was used. Key words evapotranspiration; SEBAL; METRIC; consumptive water use

37


Publ. 352, 2012), 89-93.

Two different remote sensing techniques for monitoring crop coefficient and water requirement of cotton SALEH TAGHVAEIAN1, CHRISTOPHER M. U. NEALE1, CARLOS A. C. DOS SANTOS2, DOYLE WATTS3, JOHN OSTERBERG4 & SUBRAMANIA I. SRITHARAN5

1 Civil & Environmental Engineering Department, Utah State University, Logan, Utah, USA [email protected]

2 Universidade Federal de Campina Grande, Campina Grande - PB, Brazil 3 Department of Earth & Environmental Sciences, Wright State University, Dayton, Ohio, USA 4 Denver Federal Centre, US Bureau of Reclamation, Denver, Colorado, USA 5 International Centre for Water Resources Management, Central State University, Wilberforce, Ohio, USA

Abstract Crop coefficient of cotton is estimated using two remote sensing techniques: an energy balance approach (SEBAL) and a reflectance-based method (Kcbrf). The results are compared with tabulated values in the FAO-56 paper, as well as the Kc values developed by the US Bureau of Reclamation (USBR) to be used in the “Lower Colorado River Accounting System (LCRAS).” Crop coefficients from all four sources (SEBAL, Kcbrf, FAO-56, and LCRAS) are analysed to approximate daily and seasonal water requirement of cotton for the growing season of 2008. The results show that both FAO-56 and LCRAS underestimate cotton irrigation demand due to assuming a shorter growing season and ignoring a heavy pre-irrigation event. Remotely sensed estimates of water requirement were also validated using actual irrigation depth data. Key words evapotranspiration; crop coefficient; SEBAL; FAO-56; LCRAS; southern California, USA

38


Publ. 352, 2012), 94-97.

Adjusting for background soil evaporation when interpolating evapotranspiration between satellite overpass dates JEPPE KJAERSGAARD1,2, RICHARD ALLEN1, CLARENCE ROBISON1, AYSE IRMAK3, IAN RATCLIFFE3, PARI RANADE3, RICARDO TREZZA1, RAMESH DHUNGEL1 & ERIC KRA1

1 Kimberly R&E Center, University of Idaho, 3793 N 3600 E, Kimberly, Idaho 83341, USA 2 Currently at: South Dakota Water Resources Institute, South Dakota State University, Box 2120, Brookings,

South Dakota 57007, USA [email protected]

3 School of Natural Resources, University of Nebraska-Lincoln,3310 Holdrege Street, Lincoln, Nebraska 68583, USA Abstract Landsat satellite imagery is commonly used to produce estimates of evapotranspiration (ET) at field scale with energy balance methods because of the onboard thermal imager and the high spatial resolution. Monthly and, ultimately, seasonal ET depths are generally based on only one “snapshot” of ET per month. A potential shortfall in basing integrated ET averages on periodic snapshots from a satellite is that local or regional precipitation events antecedent to the satellite images may unduly dominate the ETrF image and may not represent evaporation from rainfall averaged over the monthly period. In addition, some rain events may occur in between satellite images that are not “seen” in a subsequent image, and therefore those evaporation amounts are not fully accounted for. Key words water; rivers; groundwater

39


Publ. 352, 2012), 98-101.

Implementation of SEBAL algorithm with Landsat Thematic Mapper 5 in lower Colorado River Basin XIAOFANG WEI1, SUBRAMANIA I. SRITHARAN1, RAMANI KANDIAH1, JOHN OSTERBERG2, CHRISTOPHER NEALE3, KEITH FARROW1 & JOHN DAVENPORT1

1 Department of Water Resources Management, Central State University, 1400 Brush Row Rd, Wilberforce, Ohio 45384, USA [email protected]

2 Bureau of Reclamation, Denver Federal Center, PO Box 25007, Denver, Colorado 80225, USA 3 Department of Civil and Environmental Engineering, Utah State University, Logan, Utah 84322, USA

Abstract This paper presents the implementation and validation of the Surface Energy Balance Algorithm for Land (SEBAL) using Landsat Thematic Mapper5 (TM5). SEBAL, an image-based algorithm, was implemented in ERDAS IMAGINE 10.0 to calculate the daily evapotranspiration (ET) for the Lower Colorado Basin. Slope correction was taken into consideration by computing the solar declination, equation of time, hour angle, and instantaneous angle of incidence of beam radiation on sloping surfaces, which is critical for the subsequent computation of surface albedo, net radiation, and instantaneous evapotranspiration calculation. A sequence of ET images were computed for the years of 2007 and 2008, and validated with ground California Irrigation Management Information System (CIMIS) weather and ground eddy covariance tower data. This paper demonstrates that SEBAL is a robust tool for mapping and monitoring the ET rates in riparian area.


40

ords SEBAL; evapotranspiration; Landsat TM imagery


Publ. 352, 2012),102-105.

Filling satellite image cloud gaps to create complete images of evapotranspiration JEPPE KJAERSGAARD*, RICHARD ALLEN, RICARDO TREZZA, CLARENCE ROBISON, AUREO OLIVEIRA, RAMESH DHUNGEL & ERIC KRA

Kimberly R&E Center, University of Idaho, 3793 N 3600 E, Kimberly, Idaho 83341, USA * Currently at: South Dakota Water Resources Institute, South Dakota State University, Box 2120, Brookings,

South Dakota 57007, USA [email protected] Abstract Satellite images often have clouds in portions of the images. When estimating vegetation consumptive water use using the surface energy balance method METRIC, the evapotranspiration, expressed as ETrF = ET / ETr, where ETr is tall reference evapotranspiration computed from weather data, ETrF cannot be directly estimated for these areas because cloud temperature masks surface temperature and cloud albedo masks surface albedo. ETrF for clouded areas must be filled in before application of further integration processes so that those processes can be uniformly applied to an entire image. A linear interpolation is used to fill in ETrF for clouded portions of images. The linear interpolation is used rather than curvilinear interpolation, such as the spline introduced later to interpolate between cloud-corrected images, because some periods between cloud-free pixel locations can be as long as several months. Often, the change in crop vegetation amount, and thus ETrF, is uncertain during that period. Thus the use of curvilinear interpolation can become speculative. Key words evapotranspiration; METRIC; cloud gap filling

41


Publ. 352, 2012), 106-110.

Comparison of ET from two remote sensing-based surface energy models in south central Nebraska O. Z. AKASHEH1, A. IRMAK1, S. IRMAK2, I. RATCLIFFE1, R. SINGH3, P. RANADE1 & P. H. GOWDA4

1 School of Natural Resources, Univ. of Nebraska-Lincoln, 231 Hardin Hall, Lincoln, Nebraska 68583, USA [email protected]

2 Biological Systems Engineering Dept., Univ. of Nebraska-Lincoln, 241 L. W. Chase Hall Lincoln, Nebraska 68588, USA 3 US Geological Survey, EROS Data Center, Sioux Falls, South Dakota, USA 4 USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas, USA

Abstract Quantification of crop water use through evapotranspiration (ET) is very important for water resources management and irrigation scheduling. Two energy balance approaches were applied to estimate ET in south central Nebraska: (1) Mapping EvapoTranspiration at high Resolution with Internal Calibration (METRIC), and (2) Simplified Surface Energy Balance (SSEB) model. While both use remotely sensed thermal data for estimating ET, the METRIC is much more complex than the SSEB and widely used in the USA. Both ET models use the hot and cold pixel approach for scaling ET between driest and wettest pixels within an agricultural setting. Four Landsat 5 and four Landsat 7 images acquired for the 2007 growing season over path 29/row 32 were used to produce instantaneous ET. Images were selected with the least cloud cover and distributed temporally to cover different crop growth stages. ET data measured with a Bowen ratio energy balance system was used to assess the estimated ET accuracy. Statistical comparison of estimated daily ET against observed data gave an r2 of 0.73 and 0.66 for METRIC and SSEB, respectively. Both models produced the same root mean square error of 1.5 mm/d or 35% of the observed average daily ET. However, statistical comparison between METRIC and SSEB-based ET gave an r2 of 0.96, indicating that SSEB performance is comparable to METRIC. Considering the minimal amount of ancillary data required for implementation and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET. Key words semi-arid; operational ET mapping; remote sensing; energy balance

42


Publ. 352, 2012), 111-114.

Reference crop evapotranspiration estimated from geostationary satellite imagery H. A. R. DE BRUIN1, ISABEL F. TRIGO2, P. GAVILAN3, A. MARTÍNEZ-COB4 & M. P. GONZÁLEZ-DUGO3

1 Emeritus Wageningen University, The Netherlands, Overboslaan 52, Bilthoven 3721, The Netherlands [email protected]

2 Instituto de Meteorologia, Lisbon 1749-077, Portugal 3 IFAPA, Centro “Alameda del Obispo” Avd. Menéndez Pidal s/n 14080 Cordoba, Spain 4 Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Avda. Montañana 1005,

Zaragoza 50059, Spain Abstract A revised Makkink formula is presented to estimate the Reference Crop Evapotranspiration (ETo), as defined by the FAO, requiring incoming solar radiation and air temperature only, and allowing operational ETo mapping with geostationary satellite (MSG) imagery. For 2008, daily MSG-ETo compare well with “ground-truth” data collected over well-watered “FAO-grass”. The project is carried out in the context of the LSF SAF project (http://landsaf.meteo.pt/). It is argued that solar radiation must be preferred over measured net radiation as input variable for ET0 calculations. Key words evapotranspiration; radiation; satellites

43


Publ. 352, 2012), 115-119.

Satellite-only latent heat flux estimation KANISKA MALLICK & ANDREW JARVIS

Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK [email protected] Abstract +HUH�ZH�SUHVHQW�D�QHZ�PHWKRG�IRU�UHFRYHULQJ�JOREDO�ODWHQW�KHDW�IOX[��Ȝ(��XVLQJ�VDWHOOLWH�VRXQGLQJ�LQ�conjunction with visible and infra-red geophysical products, from the AIRS (Atmospheric Infrared Sounder) and MODIS (Moderate Resolution Imaging Spectroradiometer) platforms at 1° × 1° spatial domain. This method focuses on specifying the day-night net radiation, which is then used in a dynamic surface energy balance framework with day–night land surface temperature to directly retrieve net available energy. The evaporative fraction was estimated from the water vapour and temperature profile information in a Bowen ratio framework. Evaluation of available energy and latent heat flux against 30 terrestrial flux tower sites revealed a pooled root mean square deviation (RMSD) of 98, 72 and 79 Wm-2 for net radiation, net available energy, and latent heat flux between satellite and tower, respectively. The results show particular promise of this approach for latent heat flux retrieval under warm, moist conditions, but weaknesses under arid or semi-arid conditions subject to high radiative loads. Key words Bowen ratio; latent heat flux; satellite sounder; AIRS; FLUXNET; tower; eddy covariance

44


Publ. 352, 2012), 120-123.

ETLook: a novel continental evapotranspiration algorithm H. PELGRUM1, I. J. MILTENBURG1, M. J. M. CHEEMA2, A. KLAASSE1 & W. G. M. BASTIAANSSEN1,2

1 eLeaf, Generaal Foulkesweg 28, Wageningen 6703 BS, The Netherlands [email protected]

2 Delft University of Technology, PO Box 5048, Delft 2600 GA, The Netherlands Abstract ETLook is a newly developed algorithm to compute the evapotranspiration of large areas using an array of remote sensing data: moderate resolution visible and near infrared data from the MODIS sensor, and low resolution estimates of soil moisture from the AMSRE sensor. The Penman-Monteith equation is solved separately for vegetation and soil, enabling the division of evapotranspiration into transpiration and evaporation. The ETLook algorithm has been applied in Australia, China and the Indus basin. Key words evapotranspiration; remote sensing; microwave; river basin

45


Publ. 352, 2012), 124-127.

Analysis of energy flux estimations over Italy using time-differencing models based on thermal remote sensing data C. CAMMALLERI1, M. C. ANDERSON2, G. CIRAOLO1, G. D’URSO3, W. P. KUSTAS2, C. HAIN4, L. SCHULTZ4 & J. R. MECIKALSKI4

1 Dept of Hydraulic Engineering and Environmental Applications, Università degli Studi di Palermo, Palermo, Italy [email protected]

2 US Dept of Agriculture, ARS, Hydrology and Remote Sensing Laboratory, Beltsville, Maryland 20705, USA 3 Dept of Agricultural Engineering and Agronomy, Università degli Studi di Napoli "Federico II", Naples, Italy 4 Dept of Atmospheric Science, University of Alabama-Huntsville, Huntsville, Alabama 35899, USA

Abstract Large area estimations of land surface fluxes can be a useful operational tool for up-scaling local measurements and can serve as an upper-boundary condition for higher spatial resolution applications. Given hourly measurements of radiometric surface temperature from a geostationary satellite, it is possible to derive the partitioning of energy fluxes based on the influence of the evapotranspiration process on morning surface temperature rise. In this work, the Atmosphere–Land Exchange Inverse (ALEXI) model and the Dual Temperature Difference (DTD) approach were applied in order to relate the sensible heat flux to time-differential remote observations of surface temperature obtained from Meteosat satellite data. Key words actual evapotranspiration; geostationary satellite; time-differential surface energy balance

46


Publ. 352, 2012), 128-131.

Validation of the global evapotranspiration algorithm (MOD16) in two contrasting tropical land cover types ANDERSON L. RUHOFF1,2, WALTER COLLISCHONN2, ADRIANO R. PAZ3, HUMBERTO R. ROCHA4, LUIZ E. O. C. ARAGAO5, YADVINDER MALHI6, QIAOZHEN MU7 & STEVE W. RUNNING7

1 Instituto de Ciências Humanas e da Informação, Universidade Federal do Rio Grande, Rio Grande, Brazil [email protected]

2 Instituto de Pesquisas Hidráulicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil 3 Departamento de Engenharia Civil e Ambiental, Universidade Federal da Paraíba, João Pessoa, Brazil 4 Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo, São Paulo, Brazil 5 School of Geography, University of Exeter, Exeter, UK 6 Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, UK 7 School of Forestry, University of Montana, Missoula 59812, USA

Abstract This article presents results from NASA’s EOS MOD16 Project, which aims to estimate global evapotranspiration (ET) using remote sensing and meteorological data. Our specific objective in this study was to evaluate the accuracy of the newly improved MOD16 algorithm at the Rio Grande basin, southern Brazil, using (i) ET observations at two eddy covariance (EC) flux tower sites in different land covers (savanna and sugar cane plantations) and (ii) ET estimations from hydrological model during 2001. Our results show that MOD16 8 d average, monthly ET and annual ET values are consistent with observations of the two EC sites and the hydrological model. The RMSE and bias analyses indicate that the model overestimates ET values for savannas and underestimates these values for the sugar cane and the whole basin average. Estimates are very consistent in the dry season, while the larger prediction errors occur in the wet season. Key words eddy covariance; evapotranspiration; hydrological model; LBA; MGB; MOD16; MODIS; remote sensing

47


Publ. 352, 2012), 132-136.

Integration of multi-scale thermal satellite imagery for evaluation of daily evapotranspiration at sub-field scales M. C. ANDERSON1, W. P. KUSTAS1, W. P. DULANEY1, F. GAO2 & D. SUMNER3

1 US Dept of Agriculture, Agricultural Research Service, Hydrology and Remote Sensing Laboratory, 10300 Baltimore Ave, Beltsville, Maryland 20705, USA [email protected]

2 NASA-Goddard, Greenbelt, Maryland 20771, USA 3 US Geological Survey, Orlando, Florida 32826, USA

Abstract Development of robust algorithms for routine monitoring of evapotranspiration (ET) over large areas at spatial resolutions that discriminate individual agricultural fields (<100 m resolution) will benefit an array of water resource management applications. Land-surface temperature (LST) derived from thermal infrared (TIR) remote sensing has proven to be a valuable input to surface energy balance algorithms for estimating ET and serves as an effective proxy for spatially distributed soil moisture and precipitation measurements. This paper will discuss a strategy for integrating GOES, MODIS and Landsat TIR and shortwave imagery to map daily ET at 30 m resolution. The methodology has been tested over sites in southern Florida, an area where high-resolution time-continuous ET data are urgently needed for decision making by water management agencies. Key words evapotranspiration; remote sensing; surface energy balance

48


Publ. 352, 2012), 137-140.

Atmospheric correction of Landsat TM imagery for evapotranspiration estimation in the lower Colorado River basin XIAOFANG WEI1, SUBRAMANIA I. SRITHARAN1, ANDY FRENCH2, DAVID ECKHARDT3, RAMANI KANDIAH1 & ANDRE MORTON1

1 Department of Water Resources Management, Central State University, 1400 Brush Row Rd., Wilberforce, Ohio 45384, USA [email protected]

2 US Arid Land Agricultural Research Center, USDA/ARS, 21881 North Cardon Lane, Maricopa, Arizona 85238, USA 3 Bureau of Reclamation, Denver Federal Center, PO Box 25007, Denver, Colorado 80225, USA

Abstract Atmospheric correction for remotely sensed data is an essential process for accurate estimation of evapotranspiration (ET), which assists in understanding the evapotranspiration rate of riparian vegetation and the management of water resources in the Lower Colorado River basin. A comparative study of atmospheric correction was conducted for Landsat Thematic Mapper (TM) imagery using Second Simulation of a Satellite Signal in the Solar Spectrum (6S) and ENVI’s Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) algorithms. 6S, a vector version of the radiative transfer code, takes into consideration the radiation polarization to compensate atmospheric absorption and scattering effects, while FLAASH is a MODTRAN4+ radiation transfer code solution. After the atmospheric correction, the surface reflectance values will be correlated with ground and helicopter spectroradiometer measurement to assess the atmospheric correction and thereby to provide useful information for the subsequent evapotranspiration calculation. Key words atmospheric correction; 6S; FLAASH; Landsat TM imagery


49


Publ. 352, 2012), 141-144.

Applying remotely-sensed energy balance models in Iran: potentials and limitations SAMANEH POORMOHAMMADI1, MOHAMMAD H. RAHIMIAN2 & SALEH TAGHVAEIAN3

1 Department of Environment and Natural Resources, Yazd University, Iran [email protected] 2 Iranian National Salinity Research Centre (NSRC), Yazd, Iran 3 Civil & Environmental Engineering Department, Utah State University, Logan, Utah 84322, USA

Abstract Although remotely-sensed energy balance models have existed since the early 1970s and have been widely applied and validated under different hydro-climatological conditions, only a few case studies have been carried out in Iran, a country that can benefit considerably from the results of such studies due to its arid/semi-arid climate and limited water resources. The goal of this paper is to identify the obstacles to the application of remote sensing techniques in monitoring heat and water fluxes in Iran and to investigate strategies for eliminating them. One of the greatest challenges facing Iranian researchers is gathering satellite imagery at the appropriate temporal and spatial resolution. In addition, the lack of long-term, reliable ground-based measurements is another major limiting factor. Key words remote sensing; energy balance models; agro-hydrology; Iran

50


Publ. 352, 2012)., 145-148

Utility of the thermal-based Dual-Temperature-Difference technique under strongly advective conditions during BEAREX08 WILLIAM P. KUSTAS1, JOSEPH G. ALFIERI1, MARTHA C. ANDERSON1, PAUL D. COLAIZZI2, JOHN H. PRUEGER3, JOSE L. CHAVEZ4, CHRISTOPHER M. U. NEALE5, WAYNE DULANEY1, STEVEN R. EVETT2, KAREN S. COPELAND2 & TERRY A. HOWELL2

1 USDA-Agricultural Research Service, Hydrology & Remote Sensing Lab, Bldg. 007, BARC-West, Beltsville, Maryland 20705, USA [email protected]

2 USDA-ARS Conservation and Production Research Lab, PO Drawer 10, Bushland, Texas 79012, USA 3 USDA-ARS National Lab of Agriculture and the Environment, 2110 Univ. Blvd. Ames, Iowa 50011, USA 4 Department of Civil & Environmental Engineering, Colorado State Univ., 1372 Campus Deliv., Fort Collins,

Colorado 80523, USA 5 Department of Civil and Environmental Engineering, Utah State University, 4105 Old Main Hill, Logan,

Utah 84322-4105, USA Abstract Application of most thermal remote sensing-based energy balance models requires meteorological inputs of wind speed and air temperature. These are typically obtained from the nearest weather station which is often situated in a non-ideal location having limited fetch. In addition, the uncertainty of surface temperature estimates can be several degrees due to sensor calibration issues, atmospheric effects and variation in surface emissivity. The Dual-Temperature-Difference (DTD) method, which was derived from the Two-Source Model (TSM) of Norman et al. (1995), uses a double difference of the time rate of change in radiometric and air temperature observations, and was developed to reduce errors associated with deriving the temperature gradient in complex landscapes, such as agricultural environments having a patchwork of irrigated and non-irrigated fields. The scheme is relatively simple, requiring minimal ground-based data and meteorological input from an existing synoptic weather station network. The utility of this scheme was tested with ground-based radiometric temperature observations from the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2008 (BEAREX08), conducted in the semi-arid climate of the Texas High Plains. Key words thermal remote sensing; two-source energy balance modelling; BEAREX08; non-local meteorological forcing data


51


Publ. 352, 2012), 149-153.

Towards an improved mapping of evapotranspiration in semi-arid regions MUSTAFA GOKMEN1, CHRISTIAAN VAN DER TOL1, ZOLTÁN VEKERDY1, WOUTER VERHOEF1, OKKE BATELAAN2,3 & HASAN Z. SARIKAYA4

1 Department of Water Resources, Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede 7500 AE, The Netherlands [email protected]

2 Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Elsene 1050, Belgium 3 Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Leuven 3000, Belgium 4 Ministry of Environment and Forestry of Turkey, Ankara, Turkey

Abstract In drylands, evapotranspiration is mainly limited by soil moisture, but current surface energy balance models do not directly make use of this fact. We tested the single-source energy balance model SEBS in a semi-arid region and showed that SEBS is significantly overestimating the evaporative fraction for sparsely vegetated drylands. As an alternative for such conditions, we derived an empirical function of soil moisture, temperature gradient and NDVI, which performed significantly better. This was then integrated with the evaporative fraction output of SEBS for an improved mapping of evapotranspiration in a semi-arid region. Ground measurements of the evaporative fraction from five Bowen ratio energy balance systems were used first to test SEBS and then to calibrate the empirical equation. The resulting method uses remote sensing data and in situ air temperature measurement. Key words evapotranspiration; evaporative fraction; Bowen ratio; remote sensing; SEBS; soil moisture

52


Publ. 352, 2012), 154-157.

Modelling evapotranspiration by remote sensing parameters and agro-meteorological stations ANTONIO H. DE C. TEIXEIRA

Embrapa Semi-arid, PO Box 23, 56302-970, Petrolina, Pernambuco, Brazil [email protected] Abstract Field energy balances from irrigated and natural ecosystems, together with a net of agro-meteorological stations, were used to develop a model for actual evapotranspiration (ET) quantification, based on the ratio of actual to reference evapotranspiration and the relation of this ratio to remote sensing parameters. The model was applied in the Brazilian semi-arid region to analyse the regional ET, making use of Landsat images and a geographic information system. After comparison against field results, it showed good agreement, explaining 89% of the variances and a mean square error (RMSE) of 0.34 mm d-1. Key words satellite measurements; latent heat flux; water management

53


Publ. 352, 2012), 158-161

Modelling sensible heat flux for sparse arid natural ecosystems using multispectral video imagery SEIFELDIN H. ABDALLA1 & CHRISTOPHER M. U. NEALE2

1 Ministry of Irrigation, Khartoum, Sudan 2 Department of Civil and Environmental Engineering, Utah State University, 4110 Old Main Hill, Logan,

Utah 84322-4110, USA [email protected] Abstract A two-layer model based on a representation of the soil-canopy-atmosphere was developed and used to estimate sensible heat flux in a sparse, arid region (the Goshute Valley, Nevada, USA). In the model, the spatial distribution of the aerodynamic resistances of the different vegetation and soil types is accounted for using the height, specific area, temperature, and emissivity of vegetation and soil classes. Surface temperatures were mapped using an airborne thermal scanner. Calibrated high-resolution multispectral video imagery (pixel size of 0.15 m) acquired from an aircraft was used to extract different vegetation and soil classes using the supervised classification scheme. Measurements of sensible heat flux (H) were made simultaneously using eddy covariance and Bowen ratio techniques with towers set-up in different vegetation types and density. Model simulations indicate that estimated values of sensible heat flux agreed well with observed H, and that deviations between observed versus modelled H were generally less than the expected measurement error of H at the ground-based flux stations. The model sensitivity to the soil resistance, ras, and soil temperature variations. canopy resistance, rac, canopy temperature, Tc, leaf area index (LAI), roughness coefficient (zom), and the wind speed (Uz) was estimated. In addition, the model was tested for a condition with no vegetation, assuming TSFC was all due to soil. The good agreement between the observed and estimated sensible heat flux suggests that local-scale sensible heat flux maps can be produced using airborne sensors and utilized in mesoscale atmospheric models. Key words multispectral and thermal airborne remote sensing; sensible heat flux; desert ecosystem

54


Publ. 352, 2012), 162-166.

Custom software application for analysing urban landscape water use

ADRIAN P. WELSH1, CHRISTOPHER M. U. NEALE2, JOANNA ENDTER-WADA1, & ROGER K. KJELGREN3

1 Department of Environment and Society, Utah State University, 5215 Old Main Hill, Logan, Utah 84322-5215, USA [email protected]

2 Department of Civil and Environmental Engineering, Utah State University, 4110 Old Main Hill, Logan, Utah, USA 3 Department of Plants, Soils and Climate, Utah State University, 4820 Old Main Hill, Logan, Utah, USA

Abstract A custom software application was developed to estimate urban landscape water use in a GIS environment using landscape vegetation areas classified from high-resolution airborne multispectral imagery, coupled with ground-based reference evapotranspiration data. Estimates of parcel irrigation water demand were compared with measured volumes obtained by mining urban water billing data. The software tool allows for quick visual identification of high-end users and queries to the spatial database. Key words remote sensing; landscape vegetation evapotranspiration; urban water use

55


Publ. 352, 2012), 167-170.

Determination of surface resistance to evapotranspiration by remote sensing parameters in the semi-arid region of Brazil for land-use change analyses ANTONIO H. DE C. TEIXEIRA

Embrapa Semi-arid, PO Box 23, 56302-970, Petrolina, Pernambuco, Brazil [email protected] Abstract Field energy balances from irrigated crops (vineyards and mango orchard) and natural vegetation (caatinga) together with a net of agro-meteorological stations were used to develop a model for the surface resistance (rs) to evapotranspiration at the basin scale in the semi-arid region of Brazil for land-use change analyses. It was done to make a historical picture at the municipal-district level of vegetation replacement in Pernambuco (PE) and Bahia (BA), Brazil. Although Petrolina, PE and Juazeiro, BA presented the biggest irrigated areas, the increments throughout the years (2002–2006) were smaller (213 and 171%) than those for Santa Maria, PE (275%) and for Lagoa Grande da Boa Vista, PE (260%). Key words energy balance; satellite measurements; water resources

56


Publ. 352, 2012, 171-174.

Spatial EvapoTranspiration Modelling Interface (SETMI) HATIM M. E. GELI & CHRISTOPHER M. U. NEALE

Department of Civil and Environmental Engineering, Utah State University, 4110 Old Main Hill, Logan, Utah 84322-4110, USA [email protected] Abstract In order to obtain improved estimates of spatial-temporal evapotranspiration (ET) and to study the related effects of land and near-surface atmosphere interactions, different soil vegetation atmosphere transfer models (SVAT) are coupled with a water balance model of vegetation root zone using data assimilation techniques to update soil moisture. Within this context we developed the Spatial EvpoTranspiration Modelling Interface (SETMI) in which three different thermal remote sensing-based models are included: the one layer model (OLEM), the two source model (TSM), and the Surface Energy Balance (SEBAL) to provide estimates of surface energy fluxes and daily ET. The water balance model of the root zone is the one proposed in the FAO Paper 56 which was included to provide daily and seasonal estimates of ET and was modified to use the reflectance-based basal crop coefficient (Kcbrf) obtained from remote sensing. SETMI can also be combined with simple soil water dynamics models to provide multilayer root zone soil moisture estimates. Key words remote sensing; surface energy fluxes; spatial-temporal evapotranspiration


57


Publ. 352, 2012), 175-179.

Local and global sensitivity analysis on METRIC A. IRMAK1, R. KUMAR2 & R. E. ALLEN3

1 School of Natural Resources and Civil Engineering. 3310 Holdrege St University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA [email protected]

2 Civil Engineering. 3310 Holdrege St. University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA 3 Kimberly R&E Center, University of Idaho, 3793 N 3600 E, Kimberly, Idaho 83341, USA

Abstract Numerous algorithms have been developed to utilize remote sensing data for quantifying evapotranspiration (ET). Mapping Evapotranspiration at high Resolution and with Internalized Calibration (METRICtm) is the recently introduced successor to SEBAL, and has internal calibration capabilities. The objective of this paper was to identify the key variables in the instantaneous ET estimate that are most sensitive to change in inputs in METRICtm. The ET is expressed as ETrF (fraction of reference ET). We defined two sets of error (uncertainty, bias) for this analysis: local and global. The local error assumes that the model is calibrated at two extreme conditions (wet and hot pixels) and the uncertainty exists at the local scale. For instance, when METRIC is used with a nadir-viewing satellite (i.e. Landsat), the shadows within the corn crops and trees that are viewed from nadir could lower the albedo (bi-directional), and the radiometric surface temperature. For energy balance calculation we need full hemispherical albedo. Therefore, it is important to identify if the impact of local error in albedo is substantial on final ET estimates over these vegetation types. We assumed that the parameters of near surface temperature difference (dT) were first solved during internal calibration. The sensitivity analysis was then conducted to determine which local variables contribute the most to the ETrF variation and which variables are insignificant while retaining calibration parameters. The global sensitivity analysis assumes that the error is introduced to the internal calibration. For example, if there is bias in satellite reflectance, the error will propagate into the calculation of albedo, radiation fluxes and final ET. Some of this error in reflectance will likely be removed by internal calibration of METRICtm. However, it is important to determine which variables contribute the most to the ETrF variation, which variables are not sensitive, what impact changing one variable of METRIC has on the final ETrF, how much of error in variable is removed during calibration, and propagation of error during internal calibration. Key words evapotranspiration; METRIC; sensitivity; uncertainty; bias; error

58


Publ. 352, 2012), 180-183.

Long path scintillometry: a brief review H. A. R. DE BRUIN1 & J. G. EVANS2

1 Emeritus Wageningen University, The Netherlands, Overboslaan 52, Bilthoven 3721, The Netherlands [email protected]

2 Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK Abstract A review is presented of research carried out in the last decades on the applicability of scintillometry in hydrology, meteorology and agriculture. The theoretical background is also briefly discussed. Key words scintillometry; surface fluxes on km-scale; heterogeneous terrain; atmospheric turbulence

59


Publ. 352, 2012), 184-190.

The use of large aperture scintillometer and eddy covariance system for monitoring energy and water vapour fluxes over different surfaces in the Heihe River Basin, China SHAOMIN LIU1, ZIWEI XU1 & WEIZHEN WANG2

1 State Key Laboratory of Remote Sensing Science, School of Geography, Beijing Normal University, Beijing 100875, China [email protected]

2 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Abstract We analysed the seasonal variations of energy and water vapour fluxes, with a special focus on evapotranspiration (ET) over various surfaces: irrigated cropland (Yingke, YK), alpine meadow (A’rou, AR), and spruce forest (Guantan, GT). Energy and water vapour fluxes were measured using eddy covariance systems (EC) and a large aperture scintillometer (LAS) in the Heihe River Basin, China, in 2008 and 2009. We also determined the source areas of EC and LAS measurements for each site. The results show that the main EC source area was within a radius of 200 m at all sites. The main source area for the LAS (with a path length of 2390 m) stretched along a path line about 2000 m long and 700 m wide. The ground surface conditions in the source areas changed with season and site, and there were characteristic seasonal variations in energy and water vapour fluxes at all sites. The sensible heat flux was the main term of the energy budget during the dormant season. During the growing season, the latent heat flux dominated the energy budget, and an obvious “oasis effect” was observed at YK. The monthly ET reached its peak in July at YK and June at GT in both 2008 and 2009, while at AR it reached its peak in August in 2008 and June in 2009. ET at AR measured by different scales (kilometres scale, LAS; hundred metre scale, EC) had the similar monthly variations, presenting single peak patterns (appearing in August in 2008). There are also some differences between LAS and EC measurements because of the energy imbalance of EC system, the different source areas and surface heterogeneity. Key words evapotranspiration; eddy covariance system; large aperture scintillometer

60


Publ. 352, 2012), 191-194.

Incorporating LIDAR data into scintillometer-based estimates of sensible heat flux considering different atmospheric stability conditions HATIM M. E. GELI1, CHRISTOPHER M. U. NEALE1, DOYLE R. WATTS2, JOHN OSTERBERG3 & ROBERT T. PACK1

1 Department of Civil and Environmental Engineering, Utah State University, 4110 Old Main Hill, Logan, Utah 84322-4110, USA [email protected]

2 Department of Geological Science, Wright State University, Brehm Laboratory 267, 3640 Colonel Glenn Hwy, USA 3US Bureau of Reclamation, Denver Service Center, Denver, Colorado, USA

Abstract Scintillometer-based estimates of sensible heat flux (H) are in some conditions less accurate, especially under heterogeneous surfaces and variable terrain. Some scintillometers such as BLS900 used in this study misrepresent surface heterogeneity and terrain through using an average scintillometer effective height and vegetation height. Also the performance of the scintillometer to estimates H during stable atmospheric conditions and strong advection is considered. Here we present preliminary results of a study of the effects of incorporating terrain and vegetation height data acquired using LIDAR and airborne multispectral remote sensing. This new data is used to correct scintillometer data for a dense riparian Tamarisk forest at the Cibola wildlife area in southern California collected during the summer of 2008. Key words scintillometer; sensible heat flux; LIDAR


61


Publ. 352, 2012), 195-198.

Estimating ET using scintillometers and satellites in an irrigated vineyard in the Costa De Hermosillo, Sonora, Mexico M. MULDER1, J. A. LOPEZ-IBARRA2, C. J. WATTS3, J. C. RODRIGUEZ4, O. K. HARTOGENSIS1 & A. F. MOENE1

1 Meteorology and Air Quality Group, Wageningen University, Wageningen 6701 BH, Netherlands [email protected]

2 Organismo de Cuenca Noroeste, Comisión Nacional del Agua, Hermosillo, Sonora 83280, Mexico 3 Department of Physics, University of Sonora, Hermosillo, Sonora 83280, Mexico 4 Department. of Agriculture, University of Sonora, Hermosillo, Sonora 83280, Mexico

Abstract Visible data from geostationary satellites may be combined with vegetation index data and Land Surface Temperature data from MODIS to provide estimates of incoming solar radiation and actual evapotranspiration at 1 km resolution over large areas. The methodology is evaluated using data from a optical scintillometer at an irrigated vineyard site in northwest Mexico. In general, the satellite-based estimates for ET are about 11% lower than the ET estimated with the scintillometer. These results are similar to those obtained for sites in Africa using Meteosat data, and the errors compare favourably to other methods to estimate ET using satellite data. Key words evapotranspiration; geostationary satellite; large aperture scintillometer


62


Publ. 352, 2012), 199-201.

Determining sensible and latent heat fluxes at satellite grid scales by two-wavelength scintillometry J. G. EVANS1, D. D. McNEIL1, R. J. HARDING1 & H. A. R. DE BRUIN2

1 Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK [email protected]

2 Wageningen University, Wageningen 6700, The Netherlands Abstract A novel two-wavelength scintillometry system was deployed to determine the large-area averaged evaporation over topographically complex mixed-use farmland, at scales comparable to satellite data. Good average energy balance closure of 94% indicates reliable scintillometer fluxes. For near-zero crosswind speeds the surface energy balance is up to 30% under-closed, and at high wind speeds (and high friction velocity) there is up to 25% over-closure. The method has been shown to be powerful in capturing large-area land–atmosphere heat flux information, and is a convenient, cost effective, non-invasive ground-based remote sensing technique. Key words large aperture scintillometry; two-wavelength scintillometry; sensible heat flux; latent heat flux; evaporation; remote sensing; surface energy balance

63


Publ. 352, 2012), 202-205.

Impact of pixel versus footprint approaches on empirically derived ET estimates from Landsat TM LYNN F. FENSTERMAKER1, RICHARD L. JASONI2, JAY A. ARNONE III2 & DALE A. DEVITT3

1 Desert Research Institute, 755 E. Flamingo Road, Las Vegas 89119, Nevada, USA [email protected]

2 Desert Research Institute, 2215 Raggio Parkway, Reno 89512, Nevada, USA 3 University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas 89154-4004, Nevada, USA

Abstract A study involving empirical relationships between average growing season NDVI and total annual evapotranspiration (ET) from eddy covariance (EC) examined two approaches to extract average growing season NDVI values for regression analysis. Analysis and accuracy assessment included a single pixel (SP), average within the footprint boundary (FB), and a weighted average footprint (FW) approach to better account for the areas with the most influence on tower ET measurements. The SP approach produced a 17% average error in year 1, 20% in year 2, and a combined two-year regression relationship resulted in 14% error. The FW approach was only slightly less accurate with average errors of 27% and 26%, in years 1 and 2 respectively, and a two-year regression relationship yielded 12% error. The FB approach yielded poor results (51% error). These results indicate that a multi-year regression analysis produces more accurate estimates of annual ET than a single year regression relationship and that a SP approach performed as well as the FW approach. Key words evapotranspiration; ET; semi-arid; Great Basin; remote sensing; eddy covariance footprint

64


Publ. 352, 2012),206-209

Ground-based riparian evapotranspiration measurements for remote sensing algorithms RAMANITHARAN KANDIAH1, XIAOFANG WEI1, SUBRAMANIA SRITHARAN1, DOYLE WATTS2, CHRISTOPHER NEALE3, JOHN OSTERBERG4 & SUMANTRA CHATTERJEE5

1 International Center for Water Resources Management, Central State University, Wilberforce, Ohio 45384, USA [email protected]

2 Department of Earth and Environmental Sciences, Wright State University, Fairborn, Ohio 45435, USA 3 Civil and Environmental Engineering Department, Utah State University, Logan, Utah 84322, USA 4 US Bureau of Reclamation, Denver Federal Center, Denver, Colorado 80225, USA 5 Department of Biological Systems Engineering, University of Nebraska, Lincoln, Nebraska 68583, USA

Abstract During 2007–2008, the United States Bureau of Reclamation used ground-based instrumentation to assess evapotranspiration of riparian vegetation in the Cibola Wildlife Refuge of Arizona. Data gathered from three Bowen Ratio towers and one Eddy Covariance tower was analysed. The eddy flux estimation from eddy covariance data involved various corrections in the raw data. These estimates were used to compute the daily evapotranspiration. Evapotranspiration estimates from both approaches were compared. A methodology for generating continuous daily evapotranspiration estimates using Artificial Neural Network technique was discussed. These groundtruth estimates were compared to the values from the remote sensing algorithm. Key words evapotranspiration; eddy covariance; Bowen ratio; artificial neural networks


65


Publ. 352, 2012), 210-214

How representative is a point? The spatial variability of flux measurements across short distances JOSEPH G. ALFIERI1 & PETER D. BLANKEN2

1 USDA-ARS, Hydrology and Remote Sensing Laboratory, Beltsville, Maryland 20705, USA [email protected]

2 University of Colorado, Department of Geography, Boulder, Colorado 80309, USA Abstract During the summer of 2001, the spatial variation of the surface energy fluxes across short distances was examined over a sand-sagebrush steppe ecosystem in Colorado. A pair of eddy covariance micrometeorological stations were used to test the hypothesis that fine-scale variations in the physical properties of the site result in significant variation in the surface energy balance. While one system remained stationary, the other was positioned at one of eight locations forming two concentric circles with radii of 16 and 32 m, respectively, centred on the reference station. Through a comparative analysis of the flux measurements from the two stations, it was found that statistically significant variations in the sensible, latent and soil heat fluxes were present at the study site. These variations were linked to small changes in the near-surface soil moisture content and leaf area index. The results of this study suggest there may be substantial uncertainty surrounding a single point measurement when it is used to represent the exchange of heat and moisture over a large area. This uncertainty must be considered when using in situ measurements to evaluate remote sensing products or models. Key words energy balance fluxes; eddy covariance; spatial variability

66


Publ. 352, 2012), 215-218.

A comparison of the eddy covariance and lysimetry-based measurements of the surface energy fluxes during BEAREX08 JOSEPH G. ALFIERI1, WILLIAM P. KUSTAS1, JOHN H. PRUEGER2, JOSE L. CHAVEZ3, STEVEN R. EVETT4, CHRISTOPHER M. U. NEALE5, MARTHA C. ANDERSON1, LAWRENCE E. HIPPS6, KAREN S. COPELAND4, TERRY A. HOWELL4, ANDREW N. FRENCH7, WAYNE DULANEY1 & LYNN McKEE1

1 USDA-ARS Hydrology and Remote Sensing Laboratory, Beltsville, Maryland 20705, USA [email protected]

2 USDA-ARS National Laboratory for Agriculture and the Environment, Ames, Iowa 50011, USA 3 Colorado State University, Dept. of Civil and Environmental Engineering, Ft. Collins, Colorado 80523, USA 4 USDA-ARS Conversation and Production Laboratory, Bushland, Texas 79012, USA 5 Utah State University, Dept. of Civil and Environmental Engineering, Logan, Utah 84322, USA 6 Utah State University, Dept. of Plants, Soils, and Biometeorology, Logan, Utah 84322, USA 7 USDA-ARS Arid-Land Agricultural Research Center, Maricopa, Arizona 85238, USA

Abstract Understanding the uncertainty associated with ground truth data is critical for accurately assessing remote sensing-based products and models. Using data collected with eddy covariance systems and lysimetry during the 2008 Bushland Evapotranspiration and Agricultural Remote Sensing Experiment (BEAREX08), this research sought to characterize surface energy flux measurements collected over irrigated cotton under strongly advective conditions. The results of the analysis showed substantial differences between the flux measurements, with the lysimetry-based latent heat fluxes exceeding those of the eddy covariance measurements by as much as 400 W m-2. The differences between the non-turbulent fluxes were smaller, typically on the order of 100 W m-2. Even after forcing closure of the eddy covariance data, it was not possible to reconcile the measurements. Although differences in local surface conditions were found among the measurement sites, the cause for the discrepancies between the measurements from the two methods remains unclear. It is the focus of ongoing research. Key words surface energy balance fluxes; lysimetry; eddy covariance

67


Publ. 352, 2012), 221-230

Parameterization based on NOAA-AVHRR NDVI to improve conceptual rainfall–runoff modelling in a large West African catchment ALAIN DEZETTER1 & DENIS RUELLAND2

1 IRD, 2 CNRS, UMR HydroSciences Montpellier, Maison des Sciences de l’Eau, Université Montpellier II, Case Courrier MSE, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France [email protected] Abstract A conceptual hydrological model (GR2M) is applied to a large, poorly gauged catchment in West Africa. The purpose is to simulate the rainfall–runoff relationship at a monthly time step over the period 1982–2000 during which marked hydro-climatic changes took place. The model is based on two parameters: X1 for the production function and X2 for the routing function. The size of the production reservoir is usually fixed over time by using data from the FAO soil map. Hydroclimatic data consist of observed series of rainfall, PET and discharge data. The advantage of calibrating the size of the production reservoir by using spatiotemporal satellite NDVI data from NOAA-AVHRR images is investigated. Indeed, in a context of substantial climatic variability, or even of non-stationarity of the observed series, it may be difficult for conceptual models to reproduce runoff precisely over long periods of time. Introducing a spatiotemporal vegetation signal using NDVI data enables partial capture of the effect of the climatic and environmental variability on the functioning of the catchment. Calibrating the model using these additional forcing data significantly enhances the simulation results at the basin outlet, whatever the spatial complexity considered within the watershed through lumped or semi-distributed applications of the model. This study is a first step towards the design of a production function accounting for the spatiotemporal variability of a vegetation index. Key words hydrological modelling; GR2M; NOAA-AVHRR; NDVI; parameterization; Bani River

68


Publ. 352, 2012), 231-234

Stream–aquifer interaction assessment using riparian evapotranspiration estimates from remote sensing algorithms SUBRAMANIA I. SRITHARAN1, PRAMILA KHANAL2, XIAOFANG WEI1, RAMANITHARAN KANDIAH1, MARK H. HATFIELD1, CHRISTOPHER NEALE3 & JOHNS OSTERBERG4

1 International Center for Water Resources Management, Central State University, Wilberforce, Ohio 4538, USA [email protected]

2 Environmental Studies Program, Miami University, Oxford, Ohio 45056, USA 3 Civil & Environmental Engineering Department, Utah State University, Logan, Utah 84322, USA 4 Denver Federal Center, US Bureau of Reclamation, Denver, Colorado 80225, USA

Abstract Stream–aquifer interaction in the absence of proximate, localized pumping along the stream length is a major determinant of water balance in long river reaches. There is also considerable debate on whether improving on-farm irrigation efficiency in the river valley would lead to stream-wide water use efficiency. Techniques for assessing unmeasured returns to the stream would include modelling the groundwater processes in the riverine aquifer, requiring information on hydrogeological parameters for the associated aquifers and the stream-wetted perimeter, and irrigation applications on reliable spatial and temporal scales. Assessing these parameters and operational variables is an arduous task requiring extensive drilling and testing. This study explores the technique of using water balance studies for determining unmeasured returns to the stream, using ET estimates for riparian areas from remote sensing algorithms. The study of the Colorado River reach between Parker and Imperial dams indicates the need for revising the current practice of using constant fractions of diversions in the different months to assess the unmeasured returns. Key words riparian evapotranspiration; water budget; SEBAL; stream–aquifer interaction

69


Publ. 352, 2012), 235-238.

Airborne multi-sensor platform with potential for hydrological applications: demonstration of fluorescence measurements of turbidity BJÖRN BASCHEK & AXEL WINTERSCHEID

Federal Institute of Hydrology, PO Box 200253, D-56002 Koblenz, Germany [email protected] Abstract The multi-sensor system installed on a Do228 aircraft is used in Germany for operational surveillance for maritime oil pollution. It includes radar, a laser fluorescence sensor and other near-range sensors with ultra-violet, thermal infrared and microwave channels. This system is dedicated and specialized for the detection and characterization of maritime oil spills. Nevertheless, it has potential for hydrological applications, e.g. the monitoring of turbidity or suspended particulate matter (SPM). Laser fluorescence measurements along the tidal River Elbe correspond well to the expected characteristics of turbidity distribution. Even the correlation with point measurements of SPM concentration shows promising results. Key words airborne remote sensing; sensor system; laser fluorescence; oil; turbidity; suspended particulate matter

70


Publ. 352, 2012), 239-242.

Integrated remote sensing of bathymetry and onshore topography for asset inspection, hydrology modelling and hazard assessment TODD J. MITCHELL, GILBERT SUAREZ & PHIL HOGAN

Fugro Consultants, Inc., 4820 McGrath Street #100, Ventura 93001, California, USA [email protected] Abstract Recent integration of multibeam bathymetric sonar and mobile laser scanning (LiDAR) have opened the door to a versatile and cost-effective method for remote sensing bathymetry, with riparian and onshore topographic features at the same time. These advances have made it possible to build a dataset that extends from the bed of a watercourse through the riparian zone and even into the flood plain from a single waterborne sensor platform. This is a major milestone for practical and cost-effective evaluation of both anthropogenic and natural waterways, as well as near-shore coastal regions. Such evaluations include accurate flood inundation modelling, environmental studies, geohazards identification, silt/sediment dynamics (scour and accumulation), slope stability/landslide investigation (including seamless evaluation of subaerial and underwater slope failure features) and bottom surface material hardness and classification. Key words LiDAR; remote sensing; bathymetry; surveying; laser scanning; multibeam; GIS; geographical information systems

71


Publ. 352, 2012), 243-247

Evaluating the effect of uncertainty in the delineation of a watershed over the peak flow computation LUÍSA M. S. GONÇALVES1,2, CIDÁLIA C FONTE2,3 & RICARDO GOMES1

1 Civil Engineering Department, School of Technology and Management, Polytechnic Institute of Leiria, Leiria P-2411-901, Portugal [email protected]

2 Institute for Systems and Computers Engineering at Coimbra, Coimbra P-3000-033, Portugal 3 Department of Mathematics, University of Coimbra, Coimbra P-3001 454, Portugal

Abstract The aim of this study is to evaluate the effect of the uncertainty of the Land Cover Map (LCM) and the digital elevation model (DEM), used to automatically generate the watershed, over the watershed peak flow estimation. With the developed methodology, the watershed peak flow is obtained using interval arithmetic and an interval is obtained for the peak flow that indicates all possible peak flow values. With the proposed approach the propagation of the uncertainty in the DEM and the LCM to the peak flow values is possible. The analysis of the results obtained for the presented case study enables the identification of the order of magnitude of uncertainty on the watershed peak flow value. Key words uncertainty; watershed peak flow; digital elevation model; multispectral images; soft classifiers

72


Publ. 352, 2012), 248-252

Potential impact of Sambor Dam project on Tonle Sap Lake ecosystem based on remote sensing imaging SUSHU WU1, HIROSHI ISHIDAIRA2 & WENCHAO SUN2

1 Jiangsu Hydraulic Research Institute, Nanjing, Jiangsu 210017, China [email protected]

2 Dept of Civil and Environmental Engineering, University of Yamanashi, Kofu, Yamanashi 400-8511, Japan Abstract Tonle Sap Lake (TSL) is an important region for the social-environmental development of Cambodia. The water flow exchange between the TSL and the Mekong River (MR) is a vital hydrological process that influences the ecosystem of TSL. Cambodia plans to build a dam in the mainstream of the Mekong River at Sambor, which is located upstream of the confluence between the TSL and MR. The objective of this study is to analyse the potential impact of the Sambor Dam on the ecosystem of TSL. Ocean Color Level 1A images were collected to estimate chlorophyll-a concentration distribution in TSL. MODIS satellite images of the TSL area in 2000 were analysed to establish the relationship between water level (WL) and volume (V). By giving a designed operation rule for the Sambor Dam, the possible impact was explored through the River Lake Water Exchange (RLWE) model. Key words Mekong River; Tonle Sap Lake; impact; RLWE model

73


Publ. 352, 2012), 253-256.

Multi-sensor remote sensing based modelling of the water balance of endorheic lakes on the Tibetan Plateau VOLKER HOCHSCHILD1, JAN KROPACEK1, SOPHIE BISKOP2, ANDREAS BRAUN1, FENG CHEN3, MANFRED FINK2, JOERG HELMSCHROT2, SHICHANG KANG3, PETER KRAUSE2, REIK LEITERER2, QINGHUA YE3 & WOLFGANG-ALBERT FLUEGEL2

1 Geographisches Institut, Universitaet Tuebingen, Ruemelinstr. 19-23, D-72070 Tuebingen, Germany [email protected]

2 Institut fuer Geographie, Universitaet Jena, Loebdergraben 32, D-07743 Jena, Germany 3 Institute of Tibetan Plateau Research (ITP), Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China

Abstract The water balance of endorheic lakes on the Tibetan Plateau plays an important role in the assessment of hydrological system dynamics such as glacier retreat or changing patterns of monsoonal precipitation in relation to global warming effects. Since those lakes are remote and hard to access, multi-sensor remote sensing seems to be a valuable tool to generate hydrologically relevant information as modelling input (land cover, trends in mountain lake ice cover, etc.) or a validation base (lake level changes). Integrative methodological approaches linking state-of-the-art remote sensing with distributed hydrological modelling are the only way to quantify the water balance and to provide a forecast of the future water availability on the Tibetan Plateau. Key words multi-sensor remote sensing; satellite altimetry; multi-temporal land cover classifications; snow cover mapping; lake ice monitoring; in situ field measurements; GIS-based HRU-delineation; distributed hydrological modelling; J2000

74


Publ. 352, 2012), 257-261

Effects of resolution and scale on the accuracy of “impervious fraction” for urban catchments in Australia REBECCA TREVITHICK1 & BOFU YU2

1 Department of Environment and Resources Management, 80 Meiers Road, Indooroopilly, Queensland 4068, Australia 2 School of Engineering, Griffith University, Nathan, Queensland 4111, Australia

[email protected] Abstract The fraction and spatial distribution of impervious area are vital to modelling stormwater and its quality for urban catchments. This research quantifies and compares the accuracy of impervious fraction images for an urban catchment. These fraction images were derived from two high-resolution (1-m) multispectral data sources (scanned airphotos and Quickbird imagery with a near-infrared band), at two scales: 25 m and 100 m. The maximum likelihood classification algorithm was used to produce 10 fraction images. When compared with measured impervious areas, results for the high-resolution Quickbird imagery were superior to those based on airphotos, both for the image using only visible bands and for additional images incorporating the near-infrared band with the Nash-Sutcliffe model efficiency, E, >0.80 for all fractions. On balance, the Infrared-Green-Blue combination produced best overall results with E ranging from 0.89 to 0.94, and low bias of 1–4% across both aggregation scales. Key words impervious fraction images; multispectral imagery; image classification; Quickbird

75


Publ. 352, 2012), 262-265.

Impact of dynamic albedo and vegetation fraction on the simulation of drought in southeast Australia using a regional climate model JASON P. EVANS1, MATTHEW F. McCABE2 & XIANHONG MENG1

1 Climate Change Research Centre, University of New South Wales, Sydney, Australia [email protected]

2 School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia Abstract The Weather Research and Forecasting (WRF) regional model was run from 2000 to 2009 over southeast Australia. During this period the region entered into and later (partially) recovered, from a severe drought. The model used the following physics schemes: WRF Single Moment 5-class microphysics scheme; Rapid Radiative Transfer Model (RRTM) longwave radiation scheme; Dudhia shortwave radiation scheme; Monin-Obukhov surface layer similarity; Noah land-surface scheme; Yonsei University boundary layer scheme and Kain-Fritsch cumulus physics scheme. The model simulation uses boundary conditions from the NCEP/NCAR reanalysis with an outer 50 km resolution nest and an inner 10-km resolution nest. Both nests used 30 vertical levels spaced closer together in the planetary boundary layer. WRF was run in control mode with the default climatological surface albedo and vegetation fraction datasets, as well as with these datasets prescribed using satellite data. Comparison of these simulations demonstrates the importance of capturing the dynamic nature of these fields as the climate moves into (and then out of) a persistent multi-year drought. Both simulations capture the drought reasonably well, emphasising changes in the large scale circulation as a primary cause. Differences in the surface conditions do, however, provide regional differences in the drought severity and speed of recovery. Key words Murray-Darling Basin; albedo; vegetation cover; drought

76


Publ. 352, 2012), 266-270.

Monitoring land surface changes and water deficit of Horqin Sandy Land in a changing climate HAIJING WANG1, IRENA HAJNSEK1,2 & WOLFGANG KINZELBACH1

1 Institute of Environmental Engineering, HIF D26.2, ETH Zurich, Schafmattstr. 6, Zurich CH-8093, Switzerland [email protected]

2 German Aerospace Center, Microwaves and Radar Institute, PO Box 116, Wessling D-82234, Germany Abstract This study focuses on the water deficit problem of Horqin Sandy Land, located in the West-Liao River catchment, China, where significant depletion of groundwater and strong fluctuation of surface water areas were observed between 1999 and 2007. The goal of the study is to look for a correlation between water deficit, climate change and land surface changes. Landsat ETM+/TM images were used to monitor water surface changes and derive crop coefficient maps and NDVI maps in different years. An overall water balance of a closed catchment in the region leads to the conclusion that the changes observed over the past 10 years are, above all, due to drier climate. Key words water deficit; Landsat ETM+ TM; water balance; MNDWI; NDVI; precipitation; groundwater; evapotranspiration; semi-arid region; Horqin Sandy Land


77


Publ. 352, 2012), 271-275

Sediment discharge from an agricultural watershed: investigating the influence of land-cover fragmentation using the GSSHA model ARIEL C. BLANCO1, KAZUO NADAOKA2 & MA. CECILIA R. PARINGIT3

1 Department of Geodetic Engineering, College of Engineering, University of the Philippines, Diliman, Quezon City 1101, Philippines [email protected]

2 Department of Mechanical and Environmental Informatics, Graduate School of Information Science and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan

3 Department of Geodetic Engineering, FEATI University, Manila 1003, Philippines Abstract Land-cover patterns may serve as significant predictors of sediment discharge. The GSSHA model, a distributed physically-based watershed model, was used for the Todoroki watershed (Ishigaki Island, Okinawa, Japan) to estimate sediment discharge for different land-cover conditions as inferred from Landsat images (1984–2003). Results indicate that over the past 20 years, the changing land cover of the Todoroki watershed, in the direction of increasing sugarcane areas, had enhanced sediment discharge from the watershed. However, landscape patterns exhibited a comparable or even stronger relationship with sediment discharge compared to land-cover percentages. Based on regression analyses, four pattern metrics (number of patches, radius of gyration, splitting, and cohesion) accounted for 99% of the variability of discharged sediment volume (RMSE = 9.6) compared to 89.5% represented by land-cover percentages (RMSE = 31.6). The pattern metrics plus percentages of forest and sugarcane jointly represented almost 100% of the variability (RMSE = 0.0015). Pattern metrics have more predictive capability than land-cover percentages and can improve understanding of watershed sediment discharge process. Key words sediment discharge; agricultural watershed; fragmentation metrics; GSSHA; Okinawa, Japan

78


Publ. 352, 2012), 276-279.

Earth Observation integrated modelling tool for description of the water balance and runoff production of the Tibetan Plateau GUIDO D’URSO1, WALTER IMMERZEEL2, CARLO DE MICHELE1, HONGXING ZHENG3 & MASSIMO MENENTI4

1 Ariespace s.r.l., Centro Direz. Is. A3, Napoli, Italy [email protected]

2 FutureWater, Costerweg 1G, Wageningen, The Netherlands 3 Inst. Geograph. Sci. Natural Resources, Chinese Academy of Sciences, 11A, Datun Rd., Chaoyang, Beijing, China 4 Delft University of Technology, Bldg 62, Kluyverweg 1, Delft, The Netherlands

Abstract Quantifying the spatial and temporal relationships between the different water balance terms for the entire Tibetan Plateau is a key-focus of the CEOP-AEGIS project funded by the 7th Framework Programme of the European Commission. One of the products of this project will be a prototype water balance observation system for the Tibetan Plateau, built as an integrated platform between Earth Observation products and a distributed water balance and runoff model. The prototype package will provide a quantification of the water yield being supplied to the downstream areas and it will be also used to evaluate the effects of climate change on the water yield of the Plateau. As a requirement, it will rely on an existing and expanding network of observatories and on space-borne observing systems for which data continuity is guaranteed. Earth Observation-based input will include evapotranspiration fluxes, precipitation, snowmelt and top soil moisture. Following a comparative analysis among different modelling approaches, the raster-based modelling environment PC-Raster, developed at Utrecht University, has been chosen to develop the prototype. The model PCR-GLOBWB of the Tibetan Plateau will be applied to an area of over 1.2 × 106 km2, between 27.20 and 36.70 degrees latitude and 78.20 and 99.10 degrees longitude, bordering India, Nepal and Bhutan. For a preliminary validation of PCR-GLOBWB, daily streamflow data for 2009 in a section of the Upper Yellow River have been considered, with actual evapotranspiration derived from MODIS and precipitation from TRMM. Key words Earth Observation; distributed modelling; PC-Raster

79


Publ. 352, 2012), 280-283.

Sensitivity of glacial change detection on Bridge Glacier, Canada, to horizontal datum transformations TRISTAN GOULDEN1,2, CHRIS HOPKINSON2,1 & MICHEAL N. DEMUTH

1 Process Engineering and Applied Science, Dalhousie University, Halifax B3H 4R2, Canada [email protected]

2 Applied Geomatics Research Group, NSCC Annapolis Valley Campus, Nova Scotia B0S 1P0, Canada 3 Glaciology Section, Geological Survey of Canada, Ottawa, Ontario K1A 0Y3, Canada

Abstract To chronicle the change of alpine glaciers, analysis of historical data and comparison with modern observations is necessary. This is typically performed by observing profile lines along the glacial surface with GPS, extracting elevations of the observed profile from a historical topographic map, and comparing the elevations. GPS observations and the historical topographic map are typically referenced to separate horizontal datums. This research demonstrates the sensitivity of glacial change detection to the horizontal datum considerations through a case study of Bridge Glacier in western Canada. To simulate the procedure of observing the glacial surfaces, profiles along the centreline of Bridge Glacier were derived from digital elevation models (DEMs) in obsolete and current horizontal datums from historical and contemporary observations of Bridge Glacier. The change was determined both when: (1) the horizontal datums were correctly reconciled, and (2) the horizontal datums were not correctly reconciled. It was concluded that the effects of disregarding datum considerations propagated significant error (up to 40%) in the change detection results, which may cause incorrect conclusions to be drawn about the fate of the glacial system. Key words glacial change detection; datum transformation; error

80


Publ. 352, 2012), 284-287

Detection and feature analysis of groundwater discharge points in coastal regions around Mt Chokaisan, Japan using ALOS AVNIR-2 data YOICHI KAGEYAMA, CHIEKO SHIBATA & MAKOTO NISHIDA Graduate School of Engineering and Resource Science, Akita University, 1-1 Tegata Gakuen, Akita 010-8502, Japan [email protected] Abstract Submarine groundwater discharges exist in the Japan Sea around Mt Chokaisan, Japan. However, in the coastal regions, the details regarding their properties have not yet been clarified. In our previous study, we detected groundwater discharge points arising due to the differences in freshwater and seawater by using the Landsat ETM+ signals. This study detected the groundwater discharge points by using the ALOS AVNIR-2 data with 10-m spatial resolution, and the details of seawater surface information regarding the submarine groundwater discharge were analysed. The AVNIR-2 results were also compared with the estimation map of the salinity and the ETM+ results. Key words submarine groundwater discharge; remote sensing; freshwater; ALOS AVNIR-2; coastal regions

81


Publ. 352, 2012), 288-291

Remote sensing method for estimating green and blue water footprint MIREIA ROMAGUERA1,2, MHD SUHYB SALAMA1, MAARTEN S. KROL2, ZHONGBO SU1 & ARJEN Y. HOEKSTRA2

1 Department of Water Resources, Faculty of Geo-Information Science & Earth Observation (ITC), University of Twente, NL-7500 AA Enschede, The Netherlands [email protected]

2 Department of Water Engineering and Management, Faculty of Engineering Technology, University of Twente, NL-7500 AE Enschede, The Netherlands Abstract In this paper we propose an approach to decompose the water footprint (WF) using remote sensing data on a global scale. The WF of a crop is defined as the volume of water consumed for its production, where green and blue WF stand for rain and irrigation water usage, respectively. A method has been developed to separate WF into its green and blue components by analysing time series of earth observation data and model simulations on precipitation, soil moisture, evapotranspiration, runoff and water storage. The model takes into account the typical timescale of soil moisture depletion. Soil moisture estimates are retrieved from the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E), and the Global Land Data Assimilation System (GLDAS) are employed as a test dataset. The results show the identification of irrigation events and preliminary green and blue water calculations allowing us to assess the potential of the method. Key words remote sensing; global; water footprint; green water; blue water; irrigation; evapotranspiration

82


Publ. 352, 2012), 292-295.

Analysing parameter sensitivities in a complex distributed hydrological model using remotely sensed surface temperatures SIMON STISEN1 & MATTHEW F. McCABE2

1 Geological Survey of Denmark and Greenland, Copenhagen, Denmark [email protected]

2 University of New South Wales, Sydney, Australia Abstract Through a sensitivity analysis it is shown that traditional objective functions based on stream discharge and groundwater levels cannot alone constrain a complex groundwater–surface water–energy balance model. The patterns of land surface parameters especially require a distributed observational dataset. It is suggested that the traditional lumped observations are complemented by diurnal change in remotely-sensed land surface temperature in order to minimize the quantitative uncertainty of the spatial objective functions. Key words model constraint; land surface temperature; model optimization; sensitivity analysis

83


Publ. 352, 2012), 296-299.

Monitoring and modelling water quality parameters by means of hyperspectral data ASIF M. BHATTI & SEIGO NASU

Kochi University of Technology, Kochi, 782-8502, Japan [email protected] Abstract Optical remote sensing is a useful tool for monitoring water quality parameters in inland and coastal waters. The objectives of this study focus on the utilities of Airborne Imaging Spectroradiometer for Applications (AISA) and multispectral remotely-sensed data for monitoring and modelling water quality parameters (WQPs). This paper illustrates the inversion of reflectance spectra in terms of three water quality parameters: total suspended matter, chlorophyll-a, collared dissolved organic matter (CDOM), and water itself. The in situ sub-surface hyperspectral spectroradiometer data, AISA data and model-derived spectral signatures were compared. The performance of the bio-optical model in the research study areas was thoroughly examined and the effect of WQPs on spectra was described. The factors influencing the qualitative and quantitative nature of the spectra were also analysed. As a result, it appeared that developed modelled reflectance spectra were in agreement with the measured spectral signals. The research demonstrates an example of successful application of optical models in inland and coastal waters. Key words remotely sensed data; WQPs; optical models

84


Publ. 352, 2012), 300-303.

Using SPOT-VEG based vegetation indices compared with AVHRR-based vegetation indices for drought monitoring in the south of Iran MOHAMMAD AMIN OWRANGI1, MEHRDAD RAHNAMAEI2, ALI MOHAMMAD ZADEH3 & REZA AFSHIN SHARIFAN2

1Department of Civil and Environmental Engineering, University of Western Ontario, London, Ontario, Canada [email protected]

2 Department of Water Resources Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran 3 Department of Remote Sensing, Khajeh Nasir Toosi University, Tehran 19967-15433, Iran

Abstract To evaluate the capability of SPOT-Vegetation data for hydrological drought monitoring in the Middle East, a study plan was designed involving the production of a normalized difference vegetation index (NDVI) and a vegetation condition index (VCI) and correlating their values to groundwater level data. SPOT-VEG vegetation maps were collected from 1998 to 2007. For validation, raw AVHRR images from 1998 to 2007 were collected. Geometric and radiometric corrections were performed and groundwater level statistics were collected. Standard water level index (SWI) was applied. The Pearson correlation was used to correlate NDVI and VCI values to SWI data. Good correlations were obtained between average NDVI and average three month SWI. The results indicated that SPOT-Vegetation derived NDVI and VCI reflect the SWI fluctuations in the study area well because of unlimited groundwater consumption for irrigation. Key words SPOT-VEG; NOAA-AVHRR; groundwater; hydrological drought

85


Publ. 352, 2012), 304-307.

Transformations of river bed pattern of a lowland river inferred from aerial surveys and ground penetrating radar (GPR) 0$5&,1�6à2:,.

$GDP�0LFNLHZLF]�8QLYHUVLW\��'HSW�RI�*HRJUDSKLF�DQG�*HRORJLF�6FLHQFHV��XO��']LĊJLHORZD��-��3R]QDĔ��3RODQG Abstract Aerial surveys and GPR measurements have been carried out to study an anthropogenic transformation of a lowland river bed pattern. The research was done in the Obra River valley (western Poland) which was subjected to intensive hydro-technical works at the beginning of the 19th century. Historical maps indicated functioning of braided, meandering channels that disappeared in wetlands before the period of human intervention. Three research areas representing different river bed patterns and its alterations have been selected for detailed study. Combining the aerial and the GPR surveys allowed us to discern migration phases of the Obra River meander bends, retrace the braided pattern of the river and analyse traces and forms of the anthropogenic impact. The traces of the natural river course discerned from aerial photos correspond with the spatial extent of the channel fills inferred from the GPR surveys. Key words river bed pattern; Obra River, Poland; GPR method; aerial photography

86


Publ. 352, 2012), 308-311.

Data assimilation for improving soil moisture estimation at hillslope scales: experiments with synthetic SMAP radar data ALEJANDRO N. FLORES1, DARA ENTEKHABI2 & RAFAEL L. BRAS3

1 Department of Geosciences, Boise State University, 1910 University Dr., Boise 83725, Idaho, USA [email protected] 2 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave,

Cambridge, Massachusetts 02139, USA 3 Office of the Provost, Georgia Institute of Technology, 225 North Ave., Atlanta, Georgia 30332, USA

Abstract In a series of synthetic experiments we test the hypothesis that data assimilation algorithms can be employed to improve soil moisture estimation at spatial scales of hillslopes (e.g. 100–102 m). We use the Ensemble Kalman Filter (EnKF) to update an ensemble of hillslope-scale soil moisture fields simulated by a physically-based ecohydrology model with synthetic SMAP radar observations. For sparse vegetation, assimilation of the synthetic observations substantially reduces estimation error in near-surface soil moisture (e.g. top 5 cm), relative to the synthetic true soil moisture conditions. Key components of our data assimilation system are: (1) explicit representation of the impact of hillslope-scale topography on microwave observation, and (2) a Latin Hypercube-based soil parameter generator that preserves the correlation between soil properties and improves the reproducibility of soil moisture ensemble statistics. Key words soil moisture; data assimilation; radar; hillslopes; ensemble Kalman Filter

87


Publ. 352, 2012), 312-315.

Data assimilation of space-based passive microwave soil moisture retrievals and the correction for a dynamic open water fraction BEN T. GOUWELEEUW, ALBERT I. J. M. VAN DIJK & LUIGI J. RENZULLO CSIRO Land and Water, GPO Box 1666, Canberra 2601 ACT, Australia [email protected] Abstract The large observation footprint of low-frequency satellite microwave emissions complicates the interpretation of near-surface soil moisture retrievals. While the effect of sub-footprint lateral heterogeneity is relatively limited under unsaturated conditions, open water bodies, if not accounted for, cause a strong positive bias in the satellite-derived soil moisture retrieval. This bias is generally assumed to be static and associated with large continental lakes and coastal areas. Temporal changes in the extent of smaller water bodies as small as a few percent of the sensor footprint size, however, can also cause significant and dynamic biases. We analysed the influence of open water on near-surface soil moisture retrievals from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) for three areas in Oklahoma, USA. Differences between on-ground observations or model estimates and AMSR-E retrievals were compared to dynamic estimates of open water fraction derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The comparison indicates that seasonally varying biases of up to 20% soil water content can be attributed to the presence of relatively small areas (<5%) of open water in or near the sensor footprint. The analysis presented here will help determine which of the data fields, either the retrieved parameter or the observed microwave brightness temperature, is most suitable for assimilation with simulated fields from land surface models. Key words soil moisture; passive microwave; dynamic open water fraction; data assimilation

88


Publ. 352, 2012), 316-320.

Estimating the global terrestrial hydrologic cycle through modelling, remote sensing and data assimilation MING PAN, TARA J. TROY, ALOK K. SAHOO, JUSTIN SHEFFIELD & ERIC F. WOOD

Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544, USA [email protected] Abstract This study focuses on water budget estimation using satellite-only data products over 10 continental river basins. A non-satellite merged product (which includes model, in situ and re-analysis data) is also used to evaluate each satellite precipitation (P) and evapotranspiration (ET) product. The water budget estimated from the satellite-only products is found not to close the budget over the river basins. A water budget closure scheme is employed where the budget non-closure error from each water budget component is estimated, and closure is obtained by redistributing the non-closure error using these error statistics. It is found that the satellite precipitation product carries most of the non-closure error. Key words global hydrologic cycle; remote sensing; water budget closure constraint; river basins

89


Publ. 352, 2012), 321-324.

Assimilation of remotely sensed snow cover within land surface models to support early detection of agricultural drought JOHN HALQUIST, GREGORY M. FALL & DAGANG WANG

National Operational Hydrologic Remote Sensing Center, 1735 Lake Drive West, Chanhassen, Minnesota 55317, USA [email protected] Abstract In support of the United States Geological Survey and its scientific support role to the USAID’s Famine Early Warning Systems Network (FEWS NET), the National Oceanic and Atmospheric Administration’s (NOAA) National Operational Hydrologic Remote Sensing Center (NOHRSC) is developing land surface models for the purpose of providing estimates of snow water equivalent for areas of central Asia. Snow is a critical source of freshwater for many parts of this region. Winter and spring snowpack information is an early indicator of water availability for agriculture within snow-affected regions, as well as for downstream irrigated areas. Daily synoptic modelling of regional snow packs supports the early detection of agricultural drought associated with production shortfalls that threaten food security. Consequently, snow water equivalent estimation is one key component of a famine early warning system for this region. As in situ snowpack observations are not available for most areas of Central Asia, we simulated the snow hydrology for the years of 2003–2010 and performed an analysis of the estimated snow. Key words FEWS NET; snow water equivalent; snow cover; assimilation

90


Publ. 352, 2012), 325-328.

Remote sensing and GIS in inflow estimation for reservoir operations – Magat Dam, Philippines CZAR JAKIRI S. SARMIENTO1, RHODORA M. GONZALEZ1 & PETER M. CASTRO2

1 Department of Geodetic Engineering, University of the Philippines, Diliman, Quezon City 1101, Philippines [email protected]

2 Institute of Civil Engineering, University of the Philippines, Diliman, Quezon City 1101, Philippines Abstract This study has developed two approaches to estimate inflow: (1) creation of IMBAC, a system using remote sensing (RS) data and JAVA, and (2) maximizing the use of RS data in an existing hydrologic modelling system, the US Army’s HEC-HMS. The approaches are applied to the Magat watershed, whose 117-km2 reservoir irrigates 85 000 hectares of farmland and 360-MW plant provides electricity for Luzon island. Because of the 2001 Electric Power Industry Reform Act, a complex multi-stakeholder reservoir management was formed. This study presents the results of the RS approaches to estimate inflow as an alternative to the current local approach. Key words management; simulation; GIS; decision support; Philippines

91


Publ. 352, 2012), 329-332.

Using selective drainage methods to hydrologically-condition and hydrologically-enforce LiDAR-derived surface flow SANDRA POPPENGA1, BRUCE WORSTELL2, JASON STOKER1 & SUSAN GREENLEE1

1 US Geological Survey (USGS), Earth Resources Observation and Science (EROS) Center, 47914 252nd Street, Sioux Falls, South Dakota 57198, USA [email protected]

2 Stinger Ghaffarian Technologies (SGT), Inc., contractor to the USGS EROS Center, 47914 252nd Street, Sioux Falls 57198, South Dakota Abstract The methods to extract surface flow from coarse elevation data are well documented; however, the methods to extract surface flow from high-resolution, high-vertical accuracy digital elevation models (DEMs) derived from light detection and ranging (LiDAR) are less documented, yet more complex. As lidar data are increasingly used to generate DEMS, the demand for lidar-derived surface flow escalates. Thus, the US Geological Survey has developed semi-automated selective drainage methods to extract continuous surface flow from lidar-derived DEMs. This integrated network is important in understanding surface water movement and runoff, flood inundation, and erosion. Key words selective drainage methods, LiDAR-derived surface flow, surface flow extraction, South Dakota

92


Publ. 352, 2012), 333-336

Changes in topographic context of the Yanamarey Glacier in the Tropical Peruvian Andes KYUNG IN HUH1, BRYAN G. MARK1 & CHRIS HOPKINSON2

1 Department of Geography and Byrd Polar Research Center, The Ohio State University, Columbus, Ohio 43210, USA [email protected]

2 Applied Geomatics Research Group, NSCC Annapolis Valley Campus, Nova Scotia BOV 1A0, Canada Abstract We use a combination of satellite and airborne remote sensing, digital photogrammetry and geospatial techniques to assess the surface area, volume and topographic changes of Yanamarey Glacier in the Cordillera Blanca, Peru, between 1962 and 2008. The surface area of Yanamarey Glacier lost about 85% from 1962 (1.155 km2) to 2008 (0.165 km2). The average surface lowering of the Glacier is 144 m during this period. The change in surface area and the change in volume have a positive relationship with the correlation coefficient of 0.91 from six individual year differences. Further investigation is required to explain the scaling of surface area to volume relationship in tropical glaciers in Cordillera Blanca, Peru. Key words tropical glacier; Cordillera Blanca, Peru; LiDAR; surface area and volume changes

93


Publ. 352, 2012), 337-340.

Sensitivity of modelled evapotranspiration to canopy characteristics within the Western Boreal Plain, Alberta LAURA CHASMER1, RICHARD PETRONE1, SCOTT BROWN1, CHRIS HOPKINSON2, CARL MENDOZA3, JOHN DIIWU4, WILLIAM QUINTON1 & KEVIN DEVITO5

1 Cold Regions Research Centre, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada [email protected]

2 Applied Geomatics Research Group, NSCC, Middleton, Nova Scotia, Canada 3 Dept of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada 4 Forest Management Branch, Alberta Sustainable Resource Development, Edmonton, Alberta, Canada 5 Dept of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada

Abstract In recent years, the Western Boreal Plain (WBP) of northern Alberta has undergone intense anthropogenic disturbance via oil and gas extraction, and silvicultural activities. The extent to which changes in land-cover types/characteristics affect estimates of evapotranspiration (ET) is currently unknown. This study examines the sensitivity of ET (Penman-Monteith variant) to variability in canopy structural and ground surface characteristics at eight sites and three land-cover types (mature upland mixedwood, regenerating upland mixedwood, and peatland) during the growing season in 2008. Key words boreal; evapotranspiration; remote sensing; LiDAR; vegetation structure; Alberta, Canada

94


Publ. 352, 2012), 341-344.

Hydrological implications of periglacial expansion in the Peyto Glacier catchment, Canadian Rockies CHRIS HOPKINSON1, MICHAEL N. DEMUTH2 & MICHAEL SITAR3


2 Glaciology Section, Geological Survey of Canada, Ottawa, Ontario K1A 0E9, Canada 3 Optech Inc., Vaughan, Ontario L4K 5Z8, Canada

Abstract Multi-temporal photogrammetric and LiDAR-based DEMs collected over the Peyto Glacier (1949, 1966, 1993, 2000, 2010) were analysed to quantify rates of glacial and periglacial volumetric change. During this time, exposed glacier ice area has reduced by 18% from 14.2 to 11.6 km2, while the actively downwasting lateral moraine area has increased by 70% from 0.53 to 0.90 km2. This opposite trend results in an exponential increase in the periglacial areal proportion of actively downwasting surfaces. Mean annual volumetric loss from the glacier surface has been 14 × 106 m3, with active moraine downwasting accounting for a further 0.6 × 106 m3

(4.5%). Moraine volumetric losses from 2000 to 2010 were >6%, with an additional >2% in small hanging glacier and perennial snow patch areas. These results indicate that while Peyto Glacier is undergoing continuous retreat, runoff from periglacial areas ignored in the mass balance record account for up to 8% of contemporary losses from basin storage. LiDAR data were essential to this analysis, as accurate stratification of glacial and periglacial volumetric changes are not normally feasible using traditional field and photogrammetric mass balance techniques. Key words LiDAR; DEM; glaciology; change detection; mass balance

95


Publ. 352, 2012), 345-349.

Sensitivity of topographic slope and modelled watershed soil loss to DEM resolution TRISTAN GOULDEN1,2, CHRIS HOPKINSON2,1 & ROB JAMIESON1

1 Process Engineering and Applied Science, Dalhousie University, Halifax B3H 4R2, Canada 2 Applied Geomatics Research Group, NSCC Annapolis Valley Campus, Nova Scotia B0S 1P0, Canada

Abstract A Digital Elevation Model (DEM) is a critical component for the parameterization of process-based watershed simulation models. The influence of DEM resolution on hydrological or water quality outputs is frequently ignored within watershed modelling studies. This research focuses on the effects of varying spatial DEM resolutions on the determination of slope and how this can influence sediment yield estimates within a process-based watershed model. The 784-ha Thomas Brook watershed in Nova Scotia, Canada was used as a case study. The grid spacing of a LiDAR derived DEM was created at 1, 5, 10 and 20 m and used to generate slope maps and predicted sediment loss with the Soil and Water Assessment Tool (SWAT). It was found that the occurrence of steep slopes increased in fine spatial resolution DEMs while predicted sediment loss decreased. Key words LiDAR; DEM; watershed model; sediment yield; spatial resolution

96


Publ. 352, 2012, 350-353.

Estimation of vegetation hydrodynamic density using high density airborne laser scanning data M. Z. A. RAHMAN, B. GORTE & M. MENENTI

Institute of Earth Observation and Space Systems (DEOS), Delft University of Technology, Delft 2628 BX, Netherlands [email protected] Abstract Available methods for vegetation hydrodynamic roughness estimation in a forest area using airborne laser scanning (LiDAR) data did not take into account undergrowth vegetation and could not be verified using a wide range of forest conditions due to a lack of field data. The aim of this study is to estimate vegetation hydrodynamic density using high density airborne LiDAR for trees in forest patches and isolated trees. Vegetation hydrodynamic density for trees is estimated using a regression model and the tree trunk diameter. The regression model is developed using generated point clouds from simulations of airborne LiDAR observation over simulated forest patches. Tree trunk diameter is estimated directly on the point clouds. Key words vegetation hydrodynamic density; airborne laser scanning; forest; diameter at breast height; Netherlands

97


Publ. 352, 2012), 354-358.

Relationships between snowpack depth and primary LiDAR point cloud derivatives in a mountainous environment CHRIS HOPKINSON1, JOHN POMEROY2 CHRIS DEBEER2, CHAD ELLIS2 & AXEL ANDERSON3


2 Centre for Hydrology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C5, Canada 3 Alberta Sustainable Resources Development, Government of Alberta, Calgary, Alberta T2E 7J2, Canada

Abstract Two LiDAR data sets were acquired over the Marmot Creek headwaters of the Bow River, Alberta, Canada; the first during dry snow-free conditions in August 2007, and the second during snow covered conditions in March 2008. A LiDAR snow depth model (SDM) was derived by subtracting the snow-free digital elevation model (DEM) from the digital snow surface model (SSM). Field crews were deployed coincident with the 2008 LiDAR survey to collect snow depth transects in: (a) low elevation valley locations of shallow and discontinuous snow cover; (b) alpine locations of deep but discontinuous snowpack; and (c) forested locations at intermediate elevations displaying variable depth but more continuous cover. The SDM was validated using the field measurements and then stratified by the three LiDAR point cloud derivatives: elevation, intensity and canopy fractional cover. The SDM performed favourably over the alpine transect areas with no significant bias (r2 = 0.94, n = 137), with the valley transects demonstrating a slight overestimation of 7 cm (r2 = 0.48, n = 310) and the forest transects demonstrating the weakest correlation (r2 = 0.20, n = 402) and a mean over-estimation of 13 cm. Canopy cover creates a challenge for mapping shallow snow depth with LiDAR in mountainous environments, but canopy also reduces the spatial accuracy of GPS field data so a weaker correlation is to be expected. The SDM illustrated increasing snow depth up to tree line at approximately 2250 m a.g.l. with reducing depth and cover in the alpine zone. Overall, high LiDAR intensity values were not well correlated with snowcover at the basin scale, with only 44% spatial correspondence. However, above tree line this increased to 76%, suggesting that LiDAR intensity has some value for snow covered area (SCA) mapping as long as there is no forest canopy to attenuate or split the laser pulse returns. Key words LiDAR; intensity; coniferous canopy; mountain snowpack; change detection

98


Publ. 352, 2012), 359-362.

Delineation of lakes and channels in the Mackenzie Delta, NWT, using airborne LiDAR NEVILLE CRASTO1,2, CHRIS HOPKINSON2,1, PHILIP MARSH3, DONALD L. FORBES4 & IAN SPOONER2

1 Applied Geomatics Research Group, 50 Elliott Road, Lawrencetown, Nova Scotia B0S 1M0, Canada [email protected]

2 Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada 3 National Hydrology Research Centre, Environment Canada, Saskatoon, Saskatchewan S7N 3H5, Canada 4 Geological Survey of Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada

Abstract A terrain-based method using locally adaptive thresholds that adjust to slope and orientation of banks was tested to delineate lake and channel banks in the Mackenzie Delta, NWT, Canada. Results will contribute to an improved understanding of the local hydrology, the development of a hydraulic model and studies on subsidence impacts of planned natural gas extraction projects in the area. In addition to prevalent terrain-based methods that use point elevations alone, an approach based on using a water mask was tested. Water masks can improve the accuracy of terrain-based bank delineation by: (a) suppressing the effect of low signal-to-noise areas; and (b) prioritizing regions around existing water bodies that are most likely to contain sill points. Key words LiDAR; river channel delineation; digital terrain analysis

99


Publ. 352, 2012), 363-366

Estimation of composite hydrodynamic roughness over land with high density airborne laser scanning data M. Z. A. RAHMAN, B. GORTE & M. MENENTI

Institute of Earth Observation and Space Systems (DEOS), Delft University of Technology, Delft 2628 BX, Netherlands [email protected] Abstract This paper aims at estimating a composite hydrodynamic roughness at different scales using airborne laser scanning data. The high density airborne LiDAR is used to improve: (1) the accuracy of land-cover classification, (2) the estimation of vegetation hydrodynamic density (Dv) for trees in forest patches and isolated trees, and (3) a methodology to generate composite hydrodynamic roughness. The study area is divided into several land-cover classes that employ different methods of hydrodynamic roughness estimation. Finally, each individual hydrodynamic roughness value is combined to produce composite hydrodynamic roughness maps at any desired spatial resolution. Key words composite hydrodynamic roughness; airborne laser scanning; land cover; Netherlands

100


Publ. 352, 2012), 367-370.

SWEHydro Model and AMSR-E observations: an effective tool to reconstruct snowmelt runoff timing and magnitude JOAN RAMAGE & KATHRYN A. SEMMENS

Earth and Environmental Sciences, 1 W. Packer Ave, Lehigh University, Bethlehem, Pennsylvania 18015-3001, USA [email protected] Abstract Snowmelt timing and snow water equivalent (SWE) from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) are used as inputs to the SWEHydro model to simulate spring snowmelt runoff in high-latitude, snow-dominated drainages. AMSR-E data are used to determine the timing of melt onset and snow saturation based on changes in brightness temperature (Tb) and diurnal amplitude variations (DAV). Pre-melt SWE data is combined with terrain information and melt rate estimates to calculate runoff. The model uses four parameters: snowmelt rate during and after melt transition (defined by Tb and DAV thresholds), and flow timing during and after melt transition. The model effectively simulates spring freshet, peak timing and magnitude in basins lacking sufficient meteorological measurements. Simulated freshet timing is strongly related to snowmelt timing, and the modelled hydrograph is most dependent on the flow timing parameter. We compare the model response in the Pelly and Stewart tributaries to the Yukon River to evaluate model parameters under varying conditions. Key words AMSR-E; SWEHydro; snowmelt runoff; Yukon

101


Publ. 352, 2012), 371-374.

Regional and temporal patterns of soil moisture during CLASIC using passive microwave satellite observations RAJAT BINDLISH1, THOMAS J. JACKSON1, YONGQAIN WANG2, JIANCHENG C. SHI2,3 & JEFFERY BASARA4

1 USDA ARS Hydrology and Remote Sensing Laboratory, 10300 Baltimore Blvd, Beltsville, Maryland 20705, USA [email protected]

2 Institute of Remote Sensing Application (IRSA), China Academy of Sciences, Beijing 100101, China 3 University of California Santa Barbara, Santa Barbara, California 93106, USA 4 University of Oklahoma, Norman, Oklahoma 73019-0390, USA

Abstract The Cloud Land Surface Interaction Campaign (CLASIC) was conducted in Oklahoma during the summer of 2007, with a primary focus on the interaction between cloud formation and land surface processes, including surface soil moisture. Passive microwave observations were used to study the evolution of soil moisture conditions over the Southern Great Plains and to evaluate the potential of using this data to monitor and map flooded areas. The analyses presented here used the TMI satellite instrument. As part of the investigation, the effect of atmospheric water vapour on the microwave observations was evaluated. Atmospheric water vapour effects can be significant for high frequency microwave observations (as much as 50 K for 89 GHz and 20 K for 36.5 GHz). The effect of atmospheric water vapour decreases significantly for low frequency observations (4 K for 10 GHz). Soil moisture estimates were validated using ground and meteorological observations. The estimated soil moisture was in good agreement with in situ observations (RMSE = 0.044 m3/m3) and reflected the temporal variations resulting from precipitation events. The range and variability of estimated soil moisture was a function of land surface variables (vegetation and soils). Reliable soil moisture estimates will contribute to the study of the interaction between cloud formation and land surface. Key words soil moisture; CLASIC; TRMM; floods; passive microwave


102


Publ. 352, 2012), 375-379.

Polarimetric change detection for wetlands A. SCHMITT1, B. BRISCO2, S. KAYA2 & K. MURNAGHAN2

1 German Remote Sensing Data Center, German Aerospace Center, Oberpfaffenhofen, Münchner Straße 20, Wessling, D-82234 Germany [email protected]

2 Canada Centre for Remote Sensing, Earth Sciences Sector, Natural Resources Canada, 588 Booth Street, Ottawa, Ontario K1A 0Y7, Canada Abstract An exciting development in wetland mapping and monitoring is the use of SAR polarimetry, which uses both magnitude and phase of the backscattered radar signal for information extraction. This approach allows for the accurate delineation of flooded vegetation due to the double bounce scattering mechanism which the phase helps to identify unambiguously. Repeat pass polarimetric data is then used to monitor the temporal change in flooded vegetation. This information is useful for a variety of applications in wetland mapping and monitoring. This paper will present a novel Curvelet-based technique for the enhancement of polarimetric decomposition channels, as well as temporal differences in these channels. Starting with the Freeman-Durden and the Cloude-Pottier polarimetric decomposition of Radarsat-2 data the Curvelet image enhancement and the Curvelet change detection are applied. The results are very promising, although a validation by comparison with ground truth data still has to be done. Key words SAR; polarimetry; image enhancement; change detection; monitoring; water level; flooded vegetation

103


Publ. 352, 2012), 380-383.

Canadian SAR remote sensing for the Terrestrial Wetland Global Change Research Network (TWGCRN) S. KAYA1, B. BRISCO1, A. CULL2, A. GALLANT3, W. SADINSKI4 & D. THOMPSON5

1 Canada Centre for Remote Sensing, Earth Sciences Sector, Natural Resources Canada, 588 Booth St, Ottawa, Ontario K1A 0Y7, Canada [email protected]

2 University of Waterloo, Dept of Geography, 200 University Ave W, Waterloo, Ontario N2L 3G1, Canada 3 United States Geological Survey (USGS), Earth Resources Observation and Science (EROS) Center,

47914 252nd Street, Sioux Falls, South Dakota 57198-0001, USA 4 United States Geological Survey (USGS), Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Rd,

La Crosse, Wisconsin 54603, USA 5 Canadian Forest Service, Great Lakes Forestry Centre, Natural Resources Canada, 1219 Queen St E., Sault Ste. Marie,

Ontario P6A 2E5, Canada Abstract The Canada Centre for Remote Sensing (CCRS) has more than 30 years of experience investigating the use of SAR remote sensing for many applications related to terrestrial water resources. Recently, CCRS scientists began contributing to the Terrestrial Wetland Global Change Research Network (TWGCRN), a bi-national research network dedicated to assessing impacts of global change on interconnected wetland-upland landscapes across a large portion of North America. CCRS scientists are applying SAR remote sensing to characterize wetland components for a subset of TWGCRN landscapes in two ways: changes in surface water extent have been mapped using a multi-temporal set of RADARSAT-2 SAR data collected during April–September 2010 and changes in flooded vegetation were mapped with polarimetric RADARSAT-2 data from the same dataset to determine areas where double-bounce represented the primary scattering mechanism. The combined information from these SAR derivatives provided TWGCRN scientists with an improved monitoring capability for wetlands in these dynamic landscapes. These data are being used in conjunction with other remote sensing and field data to study interactions between landscape and animal (birds and amphibians) responses to climate/global change. Key words Terrestrial Wetland Global Change Research Network (TWGCRN); SAR; climate change; wetland

104


Publ. 352, 2012), 384-387.

Potential for improved crop yield prediction through assimilation of satellite-derived soil moisture data I. E. MLADENOVA1, W. T. CROW1, P. DORAISWAMY1, W. TENG2 & S. MILAK1

1 Hydrology and Remote Sensing Lab, USDA ARS, BARC-West, 10300 Baltimore Ave., B007, Beltsville, Maryland 20705, USA [email protected]

2 NASA Goddard Earth Sciences Data and Information Services Center (Wyle), Code 610.2, Greenbelt, Maryland 20771, USA Abstract Official US Department of Agriculture (USDA) yield estimates are summarized in the monthly World Agricultural Supply and Demand Estimates (WASDE) report released by the World Agricultural Outlook Board (WAOB). WAOB analyses contributing to yield estimates are done using the Global Agricultural Decision Support Environment (GLADSE), which is a comprehensive collection of data and tools that allows for the thorough interpretation of crop model forecasts. Soil moisture is both an essential component of these crop models and a critical data source input into GLADSE. This paper describes an Ensemble Kalman Filter based integration methodology that aims to improve the USDA Environmental Policy Integrated Climate model and GLADSE soil moisture information through the assimilation of a satellite-based surface soil moisture product derived from the Advanced Microwave Scanning Radiometer-Earth Observing System. This research, supported by NASA’s Applied Sciences Program, is a part of ongoing USDA efforts to develop data assimilation systems to improve agricultural crop yield prediction. Key words crop growth modelling; yield; soil moisture; data assimilation; Ensemble Kalman Filter

105


Publ. 352, 2012), 388-392.

Assessing the impact of Invasive Alien Plants on South African water resources using remote sensing techniques CAREN JARMAIN1 & WOUTER M. L. MEIJNINGER2

1 School of Bioresources Engineering and Environmental Hydrology, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa [email protected]

2 WaterWatch, Generaal Foulkesweg 28, Wageningen 6703 BS, The Netherlands Abstract In this study the total evapotranspiration (ET) of Invasive Alien Plants (IAPs), native vegetation and IAP-cleared areas were estimated using the Surface Energy Balance Algorithm for Land (SEBAL) model and MODIS satellite images. Subsequently the impact of clearing IAPs by the Working for Water programme on water availability in two highly invaded provinces of South Africa was quantified. Clearing IAPs has a positive effect on water resources, through a reduction in ET (13% and 6% respectively for the Western Cape and KwaZulu-Natal provinces). We showed that remote sensing data can be used to assess the available water resources. Key words Invasive Alien Plants; water use; ET; SEBAL

106


Publ. 352, 2012), 393-396.

Salt cedar biomass study in Cibola national wildlife refuge XIAOFANG WEI1, SUBRAMANIA I. SRITHARAN1, JOHN OSTERBERG2, JOHN DAVENPORT1 & TERRELL WASHINGTON1

1 Department of Water Resources Management, Central State University, 1400 Brush Row Rd. Wilberforce, Ohio 45384, USA [email protected]

2 Bureau of Reclamation, Denver Federal Center, PO Box 25007, Denver, Colorado 80225, USA Abstract Salt cedar (Tamarix spp.), an invasive species, has occupied most of the riparian areas and displaced the native vegetation in the lower Colorado River Basin, USA, causing some negative results, such as reducing biodiversity, heightening the salinity of the soils, and more notably, consuming a massive amount of water. With respect to the optimization of water management and distribution in the Lower Colorado River, a remote sensing technique has been employed to estimate the accurate amount of salt cedar present in the areas and the water consumed. The paper summarizes the field trip of summer 2009 in Cibola National Wildlife Refuge, Arizona, during which a destructive sampling was carried out to develop the allometric equations for salt cedar and other vegetation in the Refuge. The trees were clean cut and samples were dried in the laboratory to establish the allometric equation, with total basal area having the best performance. Key words biomass; salt cedar (Tamarix); water; Landsat TM imagery

107


Publ. 352, 2012), 397-400.

Basal crop coefficient from remote sensing assessment in rain-fed grapes in southeast Spain ISIDRO CAMPOS1, ALFONSO CALERA1, CLAUDIO BALBONTÍN1, ENRIQUE A. TORRES1, JOSÉ GONZÁLEZ-PIQUERAS1 & CHRISTOPHER M. U. NEALE2

1 Grupo de Teledetección y SIG. Instituto de Desarrollo Regional. Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071. Albacete, Spain [email protected]

2 Civil and Environmental Engineering. Utah State University, Logan, Utah 84322-4105, USA Abstract This paper evaluates the capability of the reflectance-based crop coefficient coupled with a water balance model to estimate crop evapotranspiration (ET) and soil water depletion on rain-fed grapes. A grape orchard located in southeast Spain was studied during the 2009 growing season. Model results were evaluated by comparison with ET measured by a Bowen Ratio and Eddy Covariance systems and soil water content measured with a Capacitance Probe system. Comparison between measured and modelled ET showed a good agreement (RMSE = 0.53 mm d-1) and the greatest difference between measured and simulated water content was 7% in relative error. By testing the model on this type of fruit tree and taking into account the results, the methodology using visible and near infrared remote sensing to obtain a reflectance-based crop coefficient gains robustness and confidence for future operational applications. Key words rain-fed grapes; evapotranspiration; dual crop coefficient; vegetation indices

108


Publ. 352, 2012), 401-405.

Coupling remote sensing and FAO-56 for a distributed water budget model in large areas: HidroMORE ENRIQUE A. TORRES, ALFONSO CALERA, JOSE GONZÁLEZ-PIQUERAS, EVA RUBIO, ISIDRO CAMPOS & CLAUDIO BALBONTIN

Grupo de Teledetección y SIG, Instituto de Desarrollo Regional, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071, Albacete, Spain [email protected] Abstract The approach presented here is based on the capability to derive the actual vegetation conditions in terms of a “transpiration coefficient” from remote sensing imagery. This “reflectance-based basal crop coefficient” (Kcb-vi), derived from multi-temporal remote sensing time series, is assimilated directly in a model that combines the FAO-56 dual crop coefficient approach and a soil water budget. In this way, only remote sensing imagery in the visible and near-infrared regions is necessary for determination of actual evapotranspiration, ET, and the other components of the water budget. Additionally, this approach allows considering the actual vegetation conditions in the ET calculation through Kcb-vi, as well as the possible ET reduction due to water shortage in the root zone, as described in the FAO-56 methodology. This procedure was implemented by a software product, HidroMORE that runs at daily scale on large areas in a spatially distributed way and at a spatial scale fixed by remote sensing imagery. Water budget components, i.e. actual evapotranspiration, irrigation water requirements, deep percolation, root soil moisture and water stress, can be estimated at pixel scale, plot scale, watershed scale or river basin scale. Application on a large area of southeast Spain has demonstrated the capability of this approach. Key words evapotranspiration; dual crop coefficient; vegetation indices; FAO-56; HidroMORE

109


Publ. 352, 2012), 406-409

Estimating Palo Verde irrigation district evapotranspiration using MODIS enhanced vegetation index and micro-meteorological data SUMANTRA CHATTERJEE1,5, SUBRAMANIA SRITHARAN2, DOYLE WATTS3 & THADDEUS TARPEY4

1 Environmental Sciences PhD Program, Wright State University, Dayton, Ohio 45435, USA 2 International Center for Water Resources Management, 111 C.J. McLin Building, Central State University,

1400 Brush Row Road, Wilberforce, Ohio 45384-1004, USA 3 Department of Earth and Environmental Sciences, Wright State University, Dayton, Ohio 45435, USA 4 Department of Mathematics and Statistics, Wright State University, Dayton, Ohio 45435, USA 5 Department of Biological Systems Engineering, University of Nebraska-Lincoln, Nebraska 68583, USA

[email protected] Abstract We developed empirical models to estimate evapotranspiration (ET) from the Palo Verde irrigation District (PVID) in California, USA. The response variable was ET published by the United States Bureau of Reclamation for 2001–2006. Solar radiation was used as the source of energy, and MODIS EVI images as an indicator of crop phenology. Vapour pressure, vapour pressure deficit and wind speed were investigated as indicators of advection. We statistically minimized multicollinearity between combinations of these variables using the Variance Inflation Factor to identify the best models. We monitored the PRESS statistic to identify the final models. To test our models’ accuracy we conducted further cross-validations in which we left out data from one calendar year. Then we estimated yearly ET and compared the latter with the actual value using the Comparative Prediction Indicator. Our results indicate that our models predicted yearly ET from PVID with errors 8% or less of USBR measurements. Key words evapotranspiration; MODIS; Enhanced Vegetation Index; micro-meteorological data

110


Publ. 352, 2012), 410-413.

Comparison of Sap Flux, Moisture Flux Tower and MODIS Enhanced Vegetation Index methods for estimating riparian evapotranspiration PAMELA L. NAGLER1, EDWARD P. GLENN2 & KIYOMI MORINO3

1 US Geological Survey, Southwest Biological Science Center, Sonoran Desert Research Station, University of Arizona, 1110 E. South Campus Drive, FCS Building, Room 129, Tucson, Arizona 85721, USA [email protected]

2 Environmental Research Laboratory of the University of Arizona, 2601 East Airport Drive, Tucson, Arizona 85706, USA 3 Laboratory of Tree Ring Research, 105 West Stadium, University of Arizona, Tucson, Arizona 85721, USA

Abstract Riparian evapotranspiration (ET) was measured on a salt cedar (Tamarix spp.) dominated river terrace on the Lower Colorado River from 2007 to 2009 using tissue-heat-balance sap flux sensors at six sites representing very dense, medium dense, and sparse stands of plants. Salt cedar ET varied markedly across sites, and sap flux sensors showed that plants were subject to various degrees of stress, detected as mid-day depression of transpiration and stomatal conductance. Sap flux results were scaled from the leaf level of measurement to the stand level by measuring plant-specific leaf area index and fractional ground cover at each site. Results were compared to Bowen ratio moisture tower data available for three of the sites. Sap flux sensors and flux tower results ranked the sites the same and had similar estimates of ET. A regression equation, relating measured ET of salt cedar and other riparian plants and crops on the Lower Colorado River to the Enhanced Vegetation Index from the MODIS sensor on the Terra satellite and reference crop ET measured at meteorological stations, was able to predict actual ET with an accuracy or uncertainty of about 20%, despite between-site differences for salt cedar. Peak summer salt cedar ET averaged about 6 mm d-1 across sites and methods of measurement. Key words Tamarix; groundwater; invasive species; Colorado River


111


Publ. 352, 2012), 414-418.

Irrigation scheduling decision support for field-scale, surface irrigation using remote sensing and ground-based data DOUGLAS HUNSAKER1, ANDREW FRENCH1, PETER WALLER2, EDUARDO BAUTISTA1, PATRICK ROYER2, KELLY THORP1, PEDRO ANDRADE-SANCHEZ3 & JOHN HEUN3

1 USDA-ARS Arid Land Agricultural Research Center, 21881 N Cardon Lane, Maricopa, Arizona 85138, USA [email protected]

2 University of Arizona, Dept of Agricultural and Biosystems Engineering, PO Box 210038, Tucson, Arizona 85721, USA 3 University of Arizona, Maricopa Agricultural Center, 37860 W Smith-Enke Road, Maricopa, Arizona 85138, USA

Abstract A spatial soil water balance modelling approach that utilized remote sensing and ground-based data was developed to guide surface irrigation scheduling of farm-size cotton borders in a field experiment in Arizona, USA. The objective was to evaluate spatial estimates of daily crop evapotranspiration (ETc) calculated for small, 4 × 8 m cells within 12 × 168 m cotton borders. Estimated ETc rates during the season compared favourably with ETc data based on soil water content measurements, though underestimating field-based ETc by an average of 0.25–0.46 mm/d. Results suggest that the spatial modelling approach could be a useful decision-making tool for improving irrigation scheduling of surface-irrigated fields. Key words crop coefficient; evapotranspiration; vegetation index; irrigation management; surface irrigation; cotton; Maricopa, Arizona

112


Publ. 352, 2012), 419-422.

Operational irrigation services from remote sensing: the irrigation advisory plan for the Campania Region, Italy GUIDO D’URSO, CARLO DE MICHELE & FRANCESCO VUOLO

ARIESPACE sr.l., Academic Spin-off Company University of Naples Federico II, Centro Direz. Is.A3, Napoli, Italy [email protected] Abstract Starting from the experience of past European projects (Demeter, PLEIADeS) on the development of space-assisted irrigation management, an operational service was started in 2008 in four irrigation districts in the Campania Region, Italy, to provide farmers and water user associations with real-time information on crop water requirements based on Earth Observation and standard methods of FAO Paper 56. The key-points of this procedure are: (a) personalised irrigation advice; (b) timely delivery of the information. Once the data are acquired by the satellite, i.e. at 10:00 h day 1, the raw image is available via FTP within 12 hours at the processing centre. The following processing steps are then applied: geometric correction (based on Ground Control Points), atmospheric correction, calculation of canopy parameters (albedo, LAI, hc). This processing is generally completed within 24 h from image download, i.e. at 12:00 h day 2. At the end of this processing phase, the following products are ready: (1) colour combination maps, (2) Crop Coefficient maps, (3) meteorological data (Precipitation, Reference Evapotranspiration) and (4) irrigation water requirements data. These products are directly delivered to each farmer using Information Technology in two ways: (1) simple text report by SMS; (2) standard report, by MMS and e-mail, including images of the fields in false colours combination and an ETp map. The approach has been validated by using independent measurements of ETa obtained from micro-meteorological instrumentations during different field campaigns. During 2009, the service has reached over 200 farmers, covering an irrigated area of about 4000 ha. Key words crop water requirement; Earth Observation; advisory service in irrigation

113


Publ. 352, 2012), 423-426.

Earth Observation for irrigation and river basin management in an operational way: the SPIDER system ALFONSO CALERA1, ANNA OSANN, GUIDO D’URSO2, CHRISTOPHER NEALE3 & JUAN MANUEL MORENO1 with contributions from other PLEIADeS partners

1 Remote Sensing and GIS Lab, University of Castilla La Mancha, Ciudad Real 13003, Spain [email protected]

2 Department of Agricultural Engineering and Agronomy, University of Naples Federico II, Naples 80138, Italy 3 Department of Civil and Environmental Engineering, Utah State University, Logan, Utah 84322, USA

Abstract Water for food production represents by far the largest share among all water uses and demands. Water management is facing increasing challenges worldwide. Earth Observation (EO)-assisted tools could be suitable in helping better management, because the comprehensive overview provided by EO allows continuous monitoring at the required spatial and temporal scales. But, the products and services derived from EO need to reach different users in a timely and useful way. The user-driven PLEIADeS project is an attempt to create operational EO-assisted tools. The technical core of this project is the System of Participatory Information, Decision support, and Expert knowledge for irrigation and River basin water management (SPIDER), based on GIS web technology. It assimilates EO time series imagery and other ancillary information to provide useful information to a wide range of stakeholders at their required space-time resolution in a non-academic, non-technical, easy-to-use and intuitive form that encourages participation. Key words Earth Observation; GIS web; water irrigation management

114


Publ. 352, 2012), 427-430.

The spatial and temporal variation of crop water consumption and the impact on water productivity in the Limpopo River basin XUELIANG CAI1, POOLAD KARIMI2, MUTSA MASIYANDIMA1 & HILMY SALLY1

1 International Water Management Institute, Southern Africa Office, 141, Cresswell Street, Weavind Park, Pretoria, South Africa [email protected]

2 International Water Management Institute, 127 Sunil Mawatha, Pellawatte, Battramulla, Sri Lanka Abstract A good understanding of crop water use and the associated benefits contribute to improved water management in the changing world. This paper analysed water consumption against precipitation and assessed crop water productivity in the southern Africa Limpopo River basin. A Simplified Surface Energy Balance (SSEB) model was adopted to estimate basin actual evapotranspiration (ETa) using remote sensing and weather measurements. The time series reference ET maps and precipitation data from Tropical Rainfall Measurement Mission (TRMM) were then overlaid together with ETa maps to assess the evolution of water balance components in the basin. The basin average ETa is 779 mm, only 46% of reference ET. The ETa of cropland varies significantly across the basin. The basin crop water productivity is very low, with great variation, which could be explained by low yields, variable water availability, and variant water management levels. Key words crop water consumption; water productivity; remote sensing; Limpopo, South Africa


115


Publ. 352, 2012), 431-434.

Remote sensing techniques as a tool for development of small scale urban runoff model WAI YEUNG YAN, AHMED SHAKER, DARKO JOKSIMOVIC & A. DIALAME

Department of Civil Engineering, Ryerson University, Toronto, Ontario M5B 2K3, Canada [email protected] Abstract The research work aims to investigate different remote sensing image processing techniques to extract relevant information for the development of urban runoff models. The techniques employ the use of stereo IKONOS satellite images to extract 3-D topographic features and conduct supervised image classification on the ortho-rectified images generated from the IKONOS satellite. Impervious surfaces and vegetation cover are extracted using the remote sensing techniques. The results reveal that data extracted from remote sensing techniques can be used effectively in modelling runoff for a small urban catchment for estimation of flood extent. However, the water balance modelling over typical climatic conditions requires further refinement in identification of impervious cover. Key words rainfall–runoff modelling; stereo IKONOS images; sensor orientation; feature extraction; image classification

116


Publ. 352, 2012), 435-439

SEBAL evapotranspiration estimates for the improvement of distributed hydrological model runoff and soil moisture predictions NAWA RAJ PRADHAN1, AARON R. BYRD1, FRED L. OGDEN2 & JAN M. H. HENDRICKX3

1US Army Corps of Engineers, Engineer Research and Development Center, Vicksburg, Mississippi 39180, USA

2 Department of Civil and Architectural Engineering, University of Wyoming, Laramie, Wyoming 82071, USA 3 Department of Earth & Environmental Science, New Mexico Tech, Socorro, New Mexico 8780, USA

Abstract Uncertainties in the initial distribution of soil moisture negatively impact predictability of runoff and future soil moisture state when using physics-based distributed-parameter hydrological models. In this study we tested a novel method for identifying the soil moisture distribution required to initialize the Gridded Surface/Subsurface Hydrologic Analysis (GSSHA) model. Surface Energy Balance Algorithms for Land (SEBAL)-derived actual evapotranspiration (ET) estimates are used in conjunction with an empirical relationship between the ratio of actual to potential ET and the soil moisture on a pixel-by-pixel basis. The resulting soil moisture estimates were used to initialize a GSSHA simulation of the 3000 km2 Kishwaukee River watershed in Illinois. We observed that the derived initial soil moisture distribution improved GSSHA simulation of soil moisture dynamics, reducing the uncertainty in runoff estimation. Key words soil moisture; evapotranspiration; GSSHA; SEBAL; distributed hydrologic modelling; hydrograph; runoff

117


Publ. 352, 2012), 440-443.

Estimating African daily evapotranspiration using MODIS and MSG data ZHIGANG SUN & MEKONNEN GEBREMICHAEL

Civil & Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, Connecticut 06269, USA [email protected] Abstract A methodology is proposed to estimate African daily evapotranspiration (ET) by merging data from the MODIS onboard the polar-orbiting Terra satellite and the SEVIRI onboard the geostationary-orbiting MSG satellite. The estimated daily ET values are compared with the eddy covariance measurements at four sites (3 savanna sites and 1 forest site) in Africa. Results show a bias of around 1 mm/day between daily ET estimates and ground measurements in warm and humid seasons, but a relatively large bias in cold and dry seasons. This bias may come from uncertainties in daily net radiation and instantaneous evaporation fraction estimations. Key words daily evapotranspiration; evaporation fraction; net radiation; soil heat flux; Sim-ReSET; MODIS; Terra; SEVIRI; MSG; Africa

118


Publ. 352, 2012),444-448

Threshold and parameter optimization method of the radar classified Z–I relationship and its application in flood forecasting SONG XINGYUAN & LUO PENG

State Key Laboratory of Water Resources and Hydropower, Wuhan University, Wuhan 430081, China [email protected] Abstract This study improves the classified Z–I relationship, making both thresholds of radar reflectivity and parameters of the Z–I relationship within each group the common parameters, and optimizing those parameters by the measured rainfall data from rainfall stations. By using the radar reflectivity data from 2005–2006 in Wuhan, China, this paper optimizes the parameters, and then compares the precision of the radar rainfall produced by the three methods before and after the Kalman filter adjustment. The results show that the improved classified Z–I relationship gives the best precision of the radar rainfall among all three methods, and also show that the flood forecasting results can be much more precise when using the improved classified Z–I relationship. Key words threshold optimization; radar classified Z–I relationship; Kalman filter; flood forecasting

119


Publ. 352, 2012), 449-453

The impacts of radar-precipitation-estimation on streamflow simulation with HSPF

huijun xu1, Qizhong guo2 & yangbo chen1 1 Natural Disaster Research Center, Sun Yat-sen University, Guangzhou 510275, China

[email protected] 2 Department of Civil and Environmental Engineering, Rutgers University, Piscataway, New Jersey 08854, USA

Abstract The HSPF model was used to simulate watershed hydrology of the Whippany River Basin (WRB) in northern New Jersey, USA. Different types of precipitation data were used as input to HSPF, including data from an individual raingauge, interpolation of gauge measurements, and NEXRAD Radar Precipitation Estimation (RPE). The PEST tool was used for the model parameter calibration. The simulated results indicate that type of the precipitation input significantly impacts the output of HSPF, with RPE particularly favourable. Key words PEST HSPF; NEXRAD; PEST

120


Publ. 352, 2012), 454-458

New generation flood forecasting in China: opportunity, research and challenge YANGBO CHEN

Center on Natural Harzard Research, Sun Yat-sen University, Xingangxi Road, Guangzhou 510275, China [email protected] Abstract This paper presents the idea of a new generation flood forecasting method and its key techniques, introduces the research progress in China, including CINRAD weather radar and precipitation estimations, the physically-based distributed hydrological model (Liuxihe model), and results from use in southern China. The challenges facing operational use of the new generation flood forecasting method in China were summarized as high resolution data acquisition, the uncertainties for flood forecasting, and real-time implementation environment and educational requirements. Key words flood forecasting; physically-based distributed hydrological model; DEM; remote sensing; weather radar; CINRAD; quantitative precipitation estimation; uncertainty

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Publ. 352, 2012)459-463

ASAR/ENVISAT images for the calibration of the wind hydrodynamic effect on Doñana wetlands BELEN MARTI-CARDONA, THANH DUC TRAN, ERNEST BLADE-CASTELLET &

JOSEP DOLZ-RIPOLLES Institut Flumen, Universitat Politècnica de Catalunya (UPC), Jordi Girona 1 D1-208, Barcelona 08034, Spain [email protected] Abstract Doñana wetlands, in southwest Spain, constitute a crucial passage and breeding site for bird migration. A hydrodynamic model of the marshes was developed in order to predict the marshes’ response to proposed restoration actions within Doñana’s catchment. Due to the flatness of Doñana’s topography, the wind-induced water surface tilting can flood considerable areas, detectable through remote sensing. This article describes how the wind drag effect was implemented into the hydrodynamic model, using formulation from the literature. Several ASAR scenes made it possible to observe this phenomenon on Doñana’s ponds. The wind-induced water displacement was simulated using the wind data registered for the 24 h prior to the ASAR acquisitions. The modelled flood patch and that derived from the ASAR images showed excellent agreement for values of the wind-profile exponential coefficient between 0.3 and 0.4. These values are consistent with direct measurements of the same coefficient reported in the literature. Key words Doñana; wetland; ASAR; flood mapping; hydrodynamic modelling; wind drag; wind profile

122


Publ. 352, 2012), 464-467.

Global scale simulation of flood plain inundation with low resolution space-borne data GUY J.-P. SCHUMANN, JEFFREY C. NEAL & PAUL D. BATES School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK [email protected] Abstract With flood risk increasing worldwide, inexpensive and globally-applicable flood management support is becoming very important. This short paper illustrates how low cost and globally available space-borne radar data might offer such support on large scales. From a test case of the summer 2007 floods in England, validation with aerial photography suggests that uncertainties in water levels from wide swath radar imagery, as well as the structure from a hydrodynamic model based on satellite data, can be estimated adequately enough for operating within an assimilation framework. Key words flooding; wide swath SAR; SRTM; low resolution; water levels; uncertainties

123


Publ. 352, 2012), 468-472.

Calibration of rainfall–runoff models based on satellite observations of river width at the basin outlet WENCHAO SUN1, HIROSHI ISHIDAIRA2, SATISH BASTOLA3 & SUSHU WU4

1 College of Water Sciences, Beijing Normal University, Xinjiekouwai Street 19, Beijing 100875, China [email protected]

2 Department of Civil and Environmental Engineering, University of Yamanashi, Kofu Yamanshi 400-8511, Japan 3 National University of Ireland, Maynooth, Co. Kildare, Ireland 4 Jiangsu Hydraulic Research Institute, Nanjing, Jiangsu 210017, China

Abstract In this study, river cross-sectional geometry was extracted from a high resolution Digital Surface Model (DSM). Then the derived information was combined with the Manning equation to describe the relation between discharge and cross-sectional water surface width. By integrating a rainfall–runoff model with this relation, which is used to describe the hydraulic relation at the basin outlet, it is possible to calibrate the rainfall–runoff model using satellite observations of river width. The method is demonstrated through a case study in the Mekong Basin. The results show that it could be an effective approach for discharge estimation in large ungauged basins. Key words large ungauged basins; Manning equation; cross-sectional geometry derived from ALOS PRISM DSM; satellite measurement of river width; calibration of rainfall–runoff model

0$1$+/ Abstracts 31.pdf · Mustafa Gokmen, Christiaan van der Tol, Zoltán Vekerdy, Wouter Verhoef,...

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