Post on 26-Jun-2020
Increasing agricultural water efficiency in Mediterranean drylands through accurate assessment of actual ETR of irrigated crops
Richard ESCADAFAL 1, Ahmed CHEHBOUNI 2, Muhammad SHATANAWI 3
1 CESBIO (CNRS, IRD ,CNES, university)Toulouse, France
2 FSS,university Cadi Ayyad, Marrakesh, Morocco
3 Faculty of Agriculture, University of Jordan, Jordan
Centre d’Etudes Spatiales de la BIOsphère
ASADWA Valparaiso 2010 * 2
Overview of ‘water augmentation’ related results from two Euromed* projects
*(funded by the European Commission)
Project IRRIMED
(2003-2007)IRD-cesbio, coord, UofW (NL), UofJ, NCARTT,MWI (JO), UCA & ORMVAH (MA), ACSAD (SY), INRGREF (TN)
Project PLEIADeS (2006-2009) (coord Spain)
IRD-cesbio , UCA & ORMVAH (MA)
Numerous experiments and models performed by a large number of fellow scientists, researchers, PhD students and field engineers => see literature published and list of colleagues:
www.irrimed.org
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Oued Tensift
Irrigated Areas
MarrakechTensift Basin / Arid Plain
Rainfall ~ 240 mm/y
PET ~ 1400 mm/y
Agriculture Uses 85% of Avalaible Water
High Atlas Moutains up to 4200 m above sea level
Moroccan test site
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Pilot area of Marakesh (Morocco)Drastic increase in irrigated areas
93000 ha in 1975
=> 181000 ha in 2002
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Remote Sensing ClimatE
Land UseIrrigation
Soils
Evapotranspiration
Infiltration
Aquifer
Monitoring the irrigation water budget
Information required:- Land Cover type- Vegetation development- Climate- Irrigation practices- Soil properties- etc.
Water consumption of irrigation is a key variable of the water balance of the watershed
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Gazon
ET0 ETc
Culture
Kc
Kcini
Kcmid
Kcend
KsETR
Culture
ET0
Reference
ETc = Kc*ET0
Potential Evapot.
ETR = Kc*Ks*ET0
Real
FAO-56 approach of ETR
Improvements seeked : ET0 & local KCs
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Rg
Vv
Dv
Ta, HR
Rain
Met Stations
Reference Evapotranspiration ET0
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Gazon
ET0 ETc
Culture
Kc
Kcini
Kcmid
Kcend
KsETR
Culture
ET0
Reference
ETc = Kc*ET0
Potential Evapot.
ETR = Kc*Ks*ET0
Real
FAO-56 approach of ETR
Improvement seeked : local KCs
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Eddy covariance (turbulence analysis)
3 D wind speed
Instantaneous vapor content Actual Evapotranspiration at plot level
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Crops measured in Crops measured in MoroccoMorocco
R3
Orange Oliveswheat
Agdal
R3
Saada 1 et 2
AgafayR3 – 2003/04
R3 – 2002/03
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Measuring fluxes in the soil
TDR (water content) thermistance (temperature)
Plaquette de flux (thermal flux )
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6m
6m
Eddy Correlation
Tripod
90 m
84 m
36 m
Sprinkler Nozel
Eddy-Correlation locationN=32 05' 21.4"E= 035 35' 46.7"
10m
30m
Scale Bar
Sprinkler Irrigation System Layout For Alfalfa CropUniversity of Jordan Agriculture Research Station
Jordan Valley
LEGEND
Boundary Border
Line
Measurements on the Jordanian test site
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Scintillometry
Large scale ETR
LLAS
DLAS
zLAS
Transmitter Receiver2ln Iσ
2nC
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Actual ETc versus predicted
Example of cauliflower in the Jordan ValleyKc for Cauliflower in the Jordan Valley
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139
Crop stage (day)
Kc-
valu
e
FAO-Kc
Modified Kc
FAO-Kc
Modified Kc for J.V.
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Actual ETc versus predicted
Example2 alfa alfa in the Jordan Valley
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61
Days from cutting
Kc-
Val
ueFAO -Kc
Modified Kc for J.V.
Many other results, in brief large differences observed (in the order of 30%) usually lower than FAO data ,
if you irrigate « by the book », you waste water
On farm Application : Saada exp. Farm / wheat
Results enhanced method Increase in
YieldWater savingYield
(Mg/ha)Irrigation (m3/ha)
Yield(Mg/ha)
Irrigation (m3/ha)
7.57.5 33703370 2.7 2.7 ±± 10 10 48004800 +170%+170% 30%30%
ResultsResults :
- done by ORMVAHdone by ORMVAH Centre des techniques d’irrigation Saâda - period (3campaigns) period (3campaigns) : 2004-2006
Application of localised irrigation , with Application of localised irrigation , with corrected Kcs from ETC measurements corrected Kcs from ETC measurements
Reference (mean)
Monitoring at farm level with satelliteexample of series of FORMOSAT-2 images acquired over the moroccan test site
Spatial resolution (multispectral mode): 8 m
Revisit time : 4 day (potentially 1 day)
4 spectral bands : blue, green, red, near-infrared
Same viewing angle
Images from Nov. 10 2005 to 10 january 2006
7,4 x 4,3 km² (total size ~ 24x24 km²)
CNES – NSPO – SPOT-image
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18 novembre 2005
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28 novembre 2005
LaboursInstallation de serres
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8 décembre 2005
Installation de serresLabours
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12 décembre 2005
Installation de serresLabours
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16 décembre 2005
Labours
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29 décembre 2005
Récolte
Installation de serres
Récolte (Orge fourrager)
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10 janvier 2006
Irrigation en cours ?
Récolte (Orge fourrager)
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Satellite monitoring of crop development
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Climate = ET0=> Given by a meteo station
Crop coefficient (Kc)
=> Estimated in the field or by satellite
FAO single crop coefficient method
ETR = ET0 * Kc
Vegetation index to estimate Kc in real time
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Potential Needs (ETM) = 13 133 000 m3
Estimated Consumption (ET) = 8 213 000 m3
Standard FAO Kc Remote Sensing Kc
Illustration of the Satellite interest
Closer to Actual Evapotranspiration
Kc
Time
Cumulated Evapotranspiration from 17/12/2002 to 31/05/2003
Kc
Time
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Application to Pumpings estimates
Pumpings
Rain
Soil Water Content
Evapotranspiration
Deep Drainage
Known surface
Irrigation
- 2 simplifying hypothesis in semi-arid plain over one year :
No Runoff (R=0) Over a year ∆S=0
Δ Soil = (Rain + G. Irrigation + Pumpings) – (ET + Percolation + Runoff)
Net Pumpings = ET – (Rain + G. Irrigation)
Net pumpings = Bulk pumpings - percolation
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Consumption estimates Accounted superficial Irrigation
Difference=
A rough approximationof raw pumping
Pumping estimates inside irrigation units
Difference = PUMPINGS
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www.cesbio.ups-tlse.fr/us/sudmed.html
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ComitéComitéScientifique Français deScientifique Français dela Désertificationla Désertification
www.csf-desertification.orgwww.csf-desertification.org
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Abou Networking …
A Global Network of Scientists for Desertification Research
c/o www.european-desertnet.eu (temporary address)