Research Article Hydrologic Responses to Land Use Change...

Research ArticleHydrologic Responses to Land Use Change in the Loess PlateauCase Study in the Upper Fenhe River Watershed

Zhixiang Lu12 Songbing Zou1 Zuodong Qin3 Yonggang Yang3

Honglang Xiao1 Yongping Wei4 Kai Zhang5 and Jiali Xie6

1Key Laboratory of Ecohydrology of Inland River Basin Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Science Lanzhou 730000 China2University of the Chinese Academy of Science Beijing 100049 China3Institute of Loess Plateau Shanxi University Taiyuan 030006 China4The Australia China Centre on Water Resources Research University of Melbourne Parkville VIC 3010 Australia5School of Soil and Water Conservation Beijing Forestry University Beijing 100083 China6Key Laboratory of Desert and Desertification Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Science Lanzhou 730000 China

Correspondence should be addressed to Songbing Zou zousongbinglzbaccn

Received 20 November 2014 Revised 12 March 2015 Accepted 16 March 2015

Academic Editor Yongqiang Zhang

Copyright copy 2015 Zhixiang Lu et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

We applied an integrated approach to investigate the impacts of land use and land cover (LULC) changes on hydrology at differentscales in the Loess Plateau of China Hydrological modeling was conducted for the LULC maps from remote sensing images attwo times in the Upper Fenhe River watershed using the SWAT model The main LULC changes in this watershed from 1995 to2010 were the transformation of farmland into forests grassland and built-up land The simulation results showed that forestedland contributed more than any other LULC class to water yield but built-up land had most impact due to small initial loss andinfiltration At basin scale a comparison of the simulated hydrological components of two LULC maps showed that there wereslight increases in average annual potential evapotranspiration actual evapotranspiration and water yield but soil water decreasedbetween the two intervals In subbasins obvious LULC changes did not have clear impacts on hydrology and the impacts may beaffected by precipitation conditions By linking a hydrological model to remote sensing image analysis our approach of quantifyingthe impacts of LULC changes on hydrology at different scales provide quantitative information for stakeholders inmaking decisionsfor land and water resource management

1 Introduction

Changing land use represents the greatest human impact onthe surface of the earth and between one-third and one-half has been altered over the last 300 years [1ndash3] Land usedirectly impacts the hydrologic components of a watershedsuch as evapotranspiration surface runoff groundwaterrecharge and streamflow [4ndash7] Many previous studies fromaround the world have demonstrated that land use signifi-cantly impacts hydrological processes [8ndash15] For exampleGhaffari et al (2010) found that a 345 decrease of grasslandwith increases of shrubland (139) and rain-fed agriculture

(121) led to a 33 increase in the amount of surface runoffand a 22 decrease in the groundwater recharge in northwestIran [8] Nie et al (2011) revealed the effects of urbanizationand agricultural development on the runoff inNorthAmerica[9] and Wang et al (2014) Li et al (2015) and Yao et al(2015) revealed the effects of urbanization land use patternsand changes on the runoff temperature evapotranspirationand surface climate in Chinese landscapes [10ndash12] Lopez-Vicente et al (2013) and Ohana-Levi et al (2015) modeledthe effects of land use change on the runoff and sedimentyield in Europersquos Pyrenees and rainfall-runoff relationshipsin an Eastern Mediterranean watershed respectively [13 14]

Hindawi Publishing CorporationAdvances in MeteorologyVolume 2015 Article ID 676030 10 pageshttpdxdoiorg1011552015676030

2 Advances in Meteorology

Wang et al (2014) assessed the impacts of land use changes onevapotranspiration quickflow infiltration and baseflow inthe upstream regions of the Three Gorges reservoir in China[15] Assessing impacts of land use and land cover (LULC)changes on hydrology is essential for watershed managementand ecological restoration [7 15 16]

In general regional impacts of land use change onhydrology vary from place to place and need to be consideredfor specific circumstances and environments [15 16] TheLoess Plateau of western China is infamous for serious soilerosion and is the main source of sediment in the middlereaches of the YellowRiver and has become the focus of worldattention As early as the 1950s China started soil and waterconservation works on the Loess Plateau in order to improvethe local environment and mitigate sediment accessions tothe middle reaches of the Yellow River and works wereexpanded after the 1970s [17 18] As a consequence land usein the Loess Plateau has undergone great changes Likewisein the past century a range of management measures werecarried out in the Fenhe River Basin on the eastern marginof the Loess Plateau Some research has been done onthe impacts of land use change on basin hydrology [19ndash22] but research on the contribution of individual LULCto the total runoff and the impacts of LULC changes onwatershed hydrology is lacking In particular there is a lackof information for evaluating the benefits of soil and waterconservation in the Fenhe River basin and the whole of theLoess Plateau where it is difficult to distinguish the impactsof LULC changes on hydrology Greater understanding ofthe contribution of individual LULC change to runoff andthe impacts of LULC changes on the hydrology at differentscales is needed to guide comprehensive natural resourcesmanagement in this region

Methods for assessing hydrological impacts of land usechanges in watersheds include comparisons of paired catch-ments statistical analysis and hydrological modeling [523 24] Among these approaches hydrological modelingis the most suitable one for use in scenario studies atdifferent scales Widely used hydrological models in stud-ies on the impacts on watershed hydrology include theHydrologic Simulation Program FORTRAN the Soil andWater Assessment Tool (SWAT) and WaTEMSEDEM [45 9 15] The SWAT model is widely used to assess hydrol-ogy and water quality in agricultural catchments aroundthe world (httpswwwcardiastateeduswat articles) It isreadily available and user-friendly for data input [25]

The overall objectives of this study are to investigate thecontributions of individual LULC change to runoff and todetermine the impacts of LULC changes on the hydrology ofthe Upper Fenhe River watershed by an integrated approachthat combines hydrological modeling and remotely senseddigital maps of LULC changes To avoid the impacts of large-scale water resource development projects on hydrologicalprocesses particularly the water diversion project from theYellow River to Fenhe River at Wanjiazhai in the study areaafter 2002 the period from 1990 to 2000 was selected as thestudy period during which sufficient data are available Thespecific objectives are (1) to investigate the LULC changes ofthewatershed from 1995 to 2010with LULCmaps determined

by remote sensing images in 1995 and 2010 (2) to calibrateand validate the SWATmodel in terms ofmonthly streamflowbased on the DEM soil map land use in 1995 and climatedata from 1990 to 2000 (3) to assess the hydrological effects ofindividual land uses and (4) to simulate responses of hydro-logic components to land use changes at basin and subbasinscales under the same climatic conditionsThe results shouldassist decision-makers in target water resources planning andvegetation restoration on the Loess Plateau

2 Study Area

The Fenhe River is located in the eastern part of the LoessPlateau North China and runs north to south throughalmost all of Shanxi Province [26]The study area is theUpperFenhe River watershed above the Hecha hydrological controlstation which measures the amount of water and sedimententering Fenhe reservoir (Figure 1) The Upper Fenhe Riverwatershed has an area of about 3242 km2 and lies betweenlatitudes 38∘001015840 and 39∘001015840 and longitudes 111∘401015840 and 112∘401015840Elevations in the basin range from 1124 to 2762m andit has an arid to semiarid climate with a mean annualprecipitation of 430mm The precipitation is concentratedbetween the months of June and September and accounts forapproximately 70 of total annual precipitation coming inthe form of high-intensity storms that often cause extremesoil erosion The average annual temperature is 90∘C witha minimum average temperature of minus5∘C in winter anda maximum average temperature of 20∘C in summer Theland use classes of the watershed include farmland forestgrassland water or wetland built-up land and unused landtheir percentages in 2010 were 30 283 3957 139073 and 001 respectively The region is covered withhighly erodible loess-derived soils Major soil series includeloess soil cinnamon soil brown soil and calcium skeletal soil

3 Methodology

A conceptual framework consisting of three stages was devel-oped (Figure 2) (1) transition matrix analysis to describethe transformations of land use from 1995 to 2010 (2)hydrological modeling to simulate hydrological componentsfor two LULC maps under the same climatic conditions and(3) comparison of the contribution of each land use class tothe watershedrsquos water yield and their hydrological effects onsubbasins

31 Transition Matrix The transition matrix of land usechange was calculated as

119861

119894119895=

[

[

[

[

[

[

[

119861

11119861

12sdot sdot sdot 119861

1119899

119861

21119861


2119899

sdot sdot sdot

119861

1198991119861


119899119899

]

]

]

]

]

]

]

(1)

where 119861 is the area of a certain kind of land use 119899 is thenumber of land use types in the study area 119894 and 119895 (119894 119895 =1 2 119899) are the types of the land use before and after

Advances in Meteorology 3

0 10(km)

0 200100(km)

20

7

2

1014

1

22

11

21

13

27

6

29

1712

28

25

32 30

3637

38

26 24

1815

23

1619

3 89

4 5

33 35

Upper Fenhe River watershed

Hecha

Jingle

Fenhe reservoir

20

Taiyuan

Fenhe

Fenhe River basin

River

BeijingS

E

N

W39∘0998400N

38∘40998400N

38∘20998400N

38∘0998400N

111∘40

998400E 112∘0998400E 112

∘20

998400E

DEM27621126

(m)

StreamSubbasinHydrologic station

Precipitation stationMeteorological station

Figure 1 Locations of study area hydrologic stations and meteorological stations

DEM

Hydrological modelingwith SWAT

Climate data LULC dataSoil data

Impacts of LULC changes on the hydrology

Model calibration and validation

Scenarios analysis

Transition matrix analysis

Figure 2 The conceptual framework for analyzing the impacts ofLULC changes on the hydrology

transition respectively and 119861119894119895is area of the land use 119894

turned into the land use 119895 The study period was defined as1995 to 2010 because soil and water conservation practiceswere first implemented from 1988 to 1997 and a second ten-year conservation project was carried out from 1998 to 2007[19 20 27] The LULC maps in 1995 and 2010 representthe surface cover conditions in the latter part of the first

conservation project and after the projects respectively TheLULC map for 1995 was used as input data to calibrate themodel

32 Hydrological Modeling

321 SWAT Model Description The SWAT 2005 model [28]was applied to data of the Upper Fenhe River watershedto assess the impacts of LULC changes on hydrologicalcomponents The SWAT model is a continuous long-termphysically based distributed model developed to assessimpacts of climate and land management on hydrologicalcomponents sediment loading and pollution transport inwatersheds [25] In the SWAT model a watershed is dividedinto subbasins Subbasins are further divided into a series ofuniform hydrological response units (HRUs) based on slopesoil and LULC changes Hydrological components sedimentyield and nutrient cycles are simulated for each HRU andthen aggregated for the subbasins

Hydrological components simulated by the SWATmodelinclude evapotranspiration (ET) surface runoff percolationlateral flow groundwater flow (return flow) and transmissionlosses [25] Evaporation and transpiration are simulated usingexponential functions of soil depth and water content anda linear function of potential evapotranspiration (PET) and


Table 1 Hydrometeorological stations in the study area

Types of stations Name Factors Data seriesHydrological stations Jingle Hecha Monthly streamflow 1990ndash2000

Precipitation stationsBaergou Haizibei Dongzhai Qianmalong GedongziHuaidao Dongmafang Ninghuabao Xinbao TangerDuanjiazhai Ximafang Suopo Jingle Kangjiahui and

Hecha

Daily precipitation 1990ndash2000

Meteorological stations Ningwu Kelan and JingleDaily precipitation and

maximum and minimum airtemperature

1990ndash2000

leaf area index Hargreavesmethod was used to estimate PETwhich was originally derived from eight years of cool-seasonAlta fescue grass lysimeter data from Davis California [29]and its reference crop is similar to grassland which is thedominant land use type in this watershed The surface runoffis estimated using a modification of the SCS curve numbermethod with daily rainfall amounts Percolation is calculatedusing the combination of a storage routing technique and acrack flow model The lateral flow is estimated simultane-ously with percolation using a kinematic storage model Thegroundwater flow (baseflow) into the channel is calculatedfrom hydraulic conductivity of the shallow aquifer distancefrom subbasin to main channel and water table height

322 SWAT Model Inputs and Outputs The input data usedin the SWAT model included a digital elevation model(DEM) soil data digital LULC maps and climate dataThe DEM was derived from the USGS National ElevationDataset with a resolution of about 90m and the soil datawere obtained from the Resources and Environment ScienceData Center Chinese Academy of Sciences with the scaleof 1 1000000 The LULC data for two times (1995 and2010) were used to assess the impacts of LULC change onhydrology and were derived from Landsat TM images witha spatial resolution of 30m using an interpretation methodThe climate data including daily values of precipitation andminimum-maximum temperature from January 1st 1990to December 31 2000 were derived from 3 meteorologicalstations and 16 precipitation stations located in and aroundthe Upper Fenhe River watershed (Table 1)

The outputs of the SWAT model used in this study werehydrological components including precipitation (P) PETactual evapotranspiration (AET) water yield (WY) and soilwater (SW)

323 SWAT Model Calibration and Validation Simulationsusing the 1995 LULC map were used to calibrate monthlystreamflows from January 1992 to December 1995 at twohydrological stations (Jingle and Hecha Figure 1) Aftermodel calibration simulations with the same model param-eters and LULC map data were used to validate monthlystreamflow from January 1996 to December 2000 (Table 2)

324 Performance Evaluation Criteria The model wascalibrated manually and three criteria were used to evaluate

Table 2 The warm-up calibration and validation period for themodel

Periods Warm-upperiod

Calibrationperiod

Validationperiod

Time series 1990-1991 1992ndash1995 1996ndash2000

performance of model calibration and validation TheNash-Sutcliffe efficiency (NSE) is a normalized statistic thatdetermines the relative magnitude of the residual variancecompared to the measured data variance NSE indicateshow well the plot of observed versus simulated data fits the1 1 line Coefficient of determination (1198772) describes thedegree of colinearity between simulated and measured dataand the proportion of the variance in the measured dataexplained by the model Percent bias (PBIAS) measures theaverage tendency of the simulated data to be larger or smallerthan their observed counterparts [29] The calibrationand validation performance for the SWAT model wereconsidered acceptable when 1198772 and NSE were greater than05 The SWAT model performance is satisfactory when NSEis larger than 05 adequate when NSE ranges from 054 to065 and very good when NSE is larger than 065The SWATmodel is rated as satisfactory when the absolute value ofPBIAS ranges from 15 to 25 rated good when from 10 to 15and very good when smaller than 10 [30]

33 Analyzing Hydrological Effects of Land Use Classes Thecalibrated and validated hydrological model was run for eachof the LULC maps (1995 and 2010) with constant DEM andsoil data from January 1990 to December 2000 (11 years)to quantify contributions of individual LULC classes to thetotal discharge and to evaluate impacts of LULC changes onhydrology at the basin and subbasin scales

4 Results and Discussion

41 LULC Changes The LULC maps of the Upper FenheRiver watershed in 1995 and 2010 are shown in Figure 3Grassland farmland and forest were the main land useclasses in the Upper Fenhe River watershed

The results of the transition matrix of LULC changesbetween 1995 and 2010 are shown in Table 3The transforma-tions among farmland forest and grassland were the main


FarmlandBuilt-up land

Water or wetlandGrasslandUnused land

Forest

N1995 2010

Figure 3 Maps for land uses and land cover in 1995 and 2010 in the Upper Fenhe River watershed

Table 3 Transition matrix of land uses from 1995 to 2010 (km2)

2010Types Farmland Forest Grassland Water or Wetland Built-up land Unused land Total

1995

Farmland 90826 1774 7966 113 699 029 101407Forest 968 84049 4588 048 082 002 89737

Grassland 5404 5911 115732 009 207 008 127271Water or wetland 095 006 011 4332 024 000 4468Built-up land 003 004 001 000 1344 000 1352Unused land 000 000 000 000 000 000 000

Total 97296 91744 128298 4502 2356 039 324235

forms of land use changes in the Upper Fenhe watershedthe area of forest and grassland increased and the area offarmland decreased Farmland showed the largest changeIt was transformed into grassland in the northern part ofthe watershed due to the implementation of the ldquograin forgreenrdquo government conservation program that compensatedfarmers for converting arable land to grassland Meanwhiledue to the social development the area of built-up landincreased markedly at the expense of farmland Finally atiny proportion of it was changed into water or wetland andunused land In the southeast a part of the watershed grass-land was turned into farmland Overall the vegetation coverincreased from 1995 to 2010 during periods of increased soiland water conservation measures

42 Model Calibration and Validation Parameter sensitivityanalysis was carried out using the model parameters iden-tified from the instructions for the calibration of the SWAT

model as given in the userrsquos manual [29] The model wascalibrated with a comprehensive model calibration method[30] The results of sensitivity analysis for the Upper FenheRiver watershed and the value of the parameters are shownin Table 4

Comparisons between simulated and observed monthlystreamflow values in the periods of calibration and validationare shown in Figure 4 Good matches were shown betweensimulated and observed values except in 1997 and 2000 Inthese two years the simulated runoff was overestimated forboth Jingle and Hecha For 1997 this may be because thewater stored in the watershed in two consecutive wet years(1995 and 1996) was released in the subsequent year For2000 the overestimation may have happened because 1999was an extremely dry year and water bodies such as smallswamps and lakes were dry and the soil was also very dryThis was followed by heavy rain in 2000 that firstly wettedthe soil filled the dry water bodies and did not form surface


Table 4 The results of parameter sensitivity analysis and calibration

Parameter Definition Hydrologic process or variable affected Rank ValueAlpha Bf Baseflow recession constant Baseflow 1 0084Cn2 Moisture condition curve number Surface runoff 2 30sim92Ch K2 Effective hydraulic conductivity in main channel alluvium (mmh) Concentration of channel 3 10Esco Soil evaporation compensation factor Soil water and soil evaporation 4 06Sol K Saturated hydraulic conductivity of first layer (mmh) Infiltration and soil water 5 0sim2000Sol Z Depth from soil surface to bottom of layer (mm) Soil water 6 0sim3500Canmx Maximum canopy storage (mm) Interception 7 0sim10Sol Awc Available soil water capacity (mmmm) Soil water 8 00125sim05

150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month

Calibration period Validation period

Simulated runoffObserved runoff

Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)

Figure 4 Monthly simulated and observed runoff in the Upper Fenhe River watershed ((a) Hecha station (b) Jingle station)

runoff This study did not take into account impounding ofwater in small water bodies which could have resulted in theoverestimation of the actual runoff in 2000

All NSE and 1198772 values for the monthly calibration andvalidation were above 080 and PBIAS values were in therange of minus15 to 0 (most PBIAS values were in the rangeof minus10 to 0) suggesting very good model performance[30] The overall performance of the model was very good asshown in Figure 4

43 Contribution of Individual LULC Changes to WatershedWater Yield The proportional contributions of five LULCchanges (ie farmland forest grassland water or wetlandand built-up land) and simulated water yield (WY) are shownin Figure 5 Grassland farmland and forest were the mainLULC changes in the Upper Fenhe River watershed andthe sum of their areas accounted for 98 of the total areaTheir contributions to water yield were up to about 98but there was no obvious positive correlation between thearea of individual LULC changes and their proportional

contributions to watershed WY The grassland class includesmainly moderately dense and sparse grassland and very littledense grassland so its water-yielding capacity was largeAlthough the area of forested land was much less than that ofthe grassland its contribution to watershed WY was slightlymore than the grasslandrsquos because forests in this watershedare mainly shrubs and sparse trees In addition the rainmostly came in the form of high-intensity storms whichcould reduce the amount of canopy interception comparedwith light rain This is similar to the results obtained by Haoet al (2004) in the upper Luohe River watershed and Songand Ma (2008) in the Nanhe River basin in the Longxi LoessPlateau [6 7] The area of farmland was between that forforests and grasslands but its water-yielding capacity wasmuch lessThe farmland in the Upper Fenhe River watershedis terraced and used to grow close and straight row-seededwheat and maize which greatly reduce the water yield

By comparing the percentages of the area of each land usetype and their contribution to water yield it was found thatan increase of built-up land was the main cause of increases


3925

2768

3128

041138

(a) Land use in 1995

283

3957

139074

30

(b) Land use in 2010

074117

2148

3878

3783


Water or wetlandGrasslandForest

(c) WY with 1995 land use

3787

074203

2093

3843



(d) WY with 2010 land use

Figure 5 Percentage of each LULC change and its contribution to the total average annual water yields (WY) for the Upper Fenhe Riverwatershed from 1992 to 2000

of runoff although the area of built-up land was very smallThis is because its water-yielding capacity was the highest dueto little initial loss and infiltration and rapid rainfall-runoffprocesses [9 31]

As LULCs changed from 1995 to 2010 the contributionof individual LULC change to watershed WY changed toobut the change process was complex because the WY is anintegrated result of LULCs soil topography and climate

44 Impacts of LULC Changes on Hydrology at the BasinScale The average basin values of P PET AET WY and SWsimulated from each LULC map in 1995 and 2010 are shownin Table 5 Compared to the LULC change baseline year of1995 the average annualWY over the watershed was 013mmhigher in 2010 Similar toWY average annual PETwith LULCin 1995 was 1026mm it increased to 1028mm by 2010 TheAET increased from 391mm for LULC in 1995 to 393mm forLULC in 2010 On the contrary the average annual SW forLULC in 2010 was 071mm lower than that in 1995

Furthermore compared to the LULC baseline year 1995the annual PET AET and SW for each year from 1992 to2000 for LULC change in 2010 changed in a similar manneras the average annual PET AET and SW But in contrast tothe size of the average annualWY for LULC in 1995 and 2010the annual WY for each year in this period did not increaseconsistently For example in years of abundant precipitationsuch as 1995 and 1996 the annual WY for the LULC changein 1995 was higher than that in 2010 This indicated that theprecipitation could affect the impacts of the LULC changes onthe hydrology in this region which was also found by Hao etal (2004) in the upper Luohe River watershed [6]

The comparison of variations of PET and AET andchanges in LULCs suggested that the increase of annual PETcould be mainly attributed to returning cropland to forestand grassland and to urban expansion from 1995 to 2010Further comparison between changes in WY and changesof LULCs indicated that an increase of WY was mainlydue to increases of urbanization which can increase thearea of impervious surfaces increase runoff and decrease


Table 5 Annual basin values of hydrologic features for the Upper Fenhe River watershed on the different land use from 1992 to 2000 (mm)

Year P Scenario with land use in 1995 Scenario with land use in 2010PET ET WY SW PET ET WY SW

1992 54096 98747 42323 6642 4110 98930 42606 6640 40371993 3954 101743 35938 3474 3610 101925 36125 3490 35661994 49339 102946 40919 6796 3868 103140 41200 6804 37631995 7092 100044 41890 21599 5446 100242 42112 21594 53761996 61865 96647 42745 16685 5357 96845 43058 16651 52481997 43726 104862 35969 7613 4958 105060 36102 7682 49031998 44872 108187 40359 5094 4310 108377 40550 5127 42781999 32771 108606 29428 3334 4565 108806 29730 3341 45172000 50118 102010 42442 5884 5454 102187 42683 5909 5352Mean 49694 102644 39112 8569 4631 102835 39352 8582 4560Note P precipitation PET potential evapotranspiration ET actual evapotranspiration WY water yield SW soil water

Table 6 LULC changes and average annual hydrologic features from 1992 to 2000 of three subbasins

Subbasin Number 7 Number 17 Number 35LULC scenario 1995 2010 1995 2010 1995 2010Total area (km2) 1099 1099 975 975 340 340Farmland () 5354 2616 1956 1959 2987 3245Forest () 931 1742 496 4651 1557 1678Grassland () 3698 5535 281 3118 5275 4823Water or wetland () 001 072 229 229 125 124Built-up land () 016 035 045 043 056 13P (mm) 49201 49201 59903 59903 47368 47368PET (mm) 91893 92655 107747 10775 107205 107218ET (mm) 39689 40363 45799 46951 3807 38008WY (mm) 6474 6657 12443 11662 7117 7217SW (mm) 7484 7222 7147 5801 2493 2312

infiltration [9 31] An association between the decreasesof SW and forest grassland and built-up land expansionfrom 1995 to 2010 could be indicated from the comparisonbetween variations of average annual SW and changes inLULC from 1995 to 2010 Expansion of forest grassland andbuilt-up land by replacing themwith farmland could promotewater infiltration and drainage because of well-developedroot systems and prevention of infiltration due to increasesin the areas of impervious surfaces

45 Impacts of LULC Changes on Hydrology at the SubbasinScale Three subbasins (numbers 7 17 and 35 in Figure 1)with obvious LULC changes were selected for analysis of theimpacts of LULC changes on hydrology at the subbasin scaleand the results are shown in Table 6 In subbasin number 7the area of farmland decreased sharply and the areas of forestgrassland water and built-up land increased from 1995 to2010 The PET AET and WY increased and in contrast theSW decreased In subbasin number 17 only the forested areadecreased and grassland area increased a little so the impactson hydrology were that AET increased clearly and WY andSW decreased In subbasin number 35 areas of farmlandforest and built-up land increased and grassland decreasedand WY increased and SW decreased By comparing the

LULC changes and the hydrological responses to them inthese three sun-basins obvious LULC changes may notshow obvious impacts on hydrology which means differentcombinations of LULCs may produce similar hydrologicaleffects Furthermore the impacts of the same LULC changeson hydrology may be different under the conditions ofdifferent precipitation intensity and distribution

5 Conclusions

In this study we aimed to investigate the impacts of LULCchanges on hydrology in Chinarsquos Loess Plateau Majorresearch findings and their implication on practices andfuture research are as follows

From 1995 to 2010 the main land use changes were thetransformations of farmland to forests and from farmlandto grassland and the area of built-up land increased atthe expense of farmland These changes were due to theimplementation of watershed management measures andsocial and economic development For the contribution ofeach LULC to the total WY of the watershed the forestgrassland and farmland areas were the largest contributorswith up to about 39 38 and 21 respectively The landuse that produced the greatest water yield was shown to be


built-up land which was higher than any other land usefollowed by forest grassland and farmland

Accompanying the LULC changes in the Upper FenheRiver watershed increases in PET AET and WY indicatedsoil and water conservation practices increased runoff whilethe expansion of the forest and grassland increased the PETand AET In addition the consumption of SW was increasedby vegetation combined with decreased infiltration becauseincreases of the built-up land resulted in decreases in SWFurthermore the precipitation could affect the impacts ofLULC changes on the hydrologic components in this arid andsemiarid area

The approach used in this study simply determined con-tributions of individual LULC classes to the total dischargeproviding quantitative information for decision-makers tomake better choices for land andwater resource planning andmanagement This approach also provides a solid example ofthe potential of hydrologic modeling using remotely senseddigital LULCs in understanding the impacts of landscapechange onwater provisioning a vital ecosystem service in theLoess Plateau of China It can be widely applied to a variety ofwatersheds where time-sequenced digital land cover data areavailable and to predict hydrological consequences to LULCchanges

Conflict of Interests

The authors declare no conflict of interests

Acknowledgments

This work was supported by the International Science ampTechnology Cooperation Program of China (2012DFA20770and 2013DFG70990) the National Natural Science Founda-tion of China (41201043 and 91125007) the National KeyTechnology RampD Program (2011BAC07B05) and ShanxiProvince Science Foundation for Youths (2012021026-3)

References

[1] J A Foley R DeFries G P Asner et al ldquoGlobal consequencesof land userdquo Science vol 309 no 5734 pp 570ndash574 2005

[2] E F Lambin B L Turner H J Geist et al ldquoThe causes of land-use and land-cover change moving beyond the mythsrdquo GlobalEnvironmental Change vol 11 no 4 pp 261ndash269 2001

[3] N Ramankutty and J A Foley ldquoEstimating historical changesin global land cover croplands from 1700 to 1992rdquo GlobalBiogeochemical Cycles vol 13 no 4 pp 997ndash1027 1999

[4] L M Mango A M Melesse M E McClain D Gann and S GSetegn ldquoLand use and climate change impacts on the hydrologyof the upper Mara River Basin Kenya results of a modelingstudy to support better resource managementrdquo Hydrology andEarth System Sciences vol 15 no 7 pp 2245ndash2258 2011

[5] D N Khoi and T Suetsugi ldquoThe responses of hydrologicalprocesses and sediment yield to land-use and climate change inthe Be River Catchment Vietnamrdquo Hydrological Processes vol28 no 3 pp 640ndash652 2014

[6] F Hao L Chen C Liu and D Dai ldquoImpact of land use changeon runoff and sediment yieldrdquo Journal of Soil and WaterConservation vol 18 no 3 pp 5ndash8 2004

[7] Y-H Song and J-H Ma ldquoSWAT-Aided research on hydro-logical responses to ecological restoration a case study of theNanhe River Basin in Huajialing of Longxi Loess Plateaurdquo ActaEcologica Sinica vol 28 no 2 pp 636ndash644 2008

[8] G Ghaffari S Keesstra J Ghodousi and H Ahmadi ldquoSWAT-simulated hydrological impact of land-use change in the Zan-janrood basin Northwest Iranrdquo Hydrological Processes vol 24no 7 pp 892ndash903 2010

[9] W Nie Y Yuan W Kepner M S Nash M Jackson and CErickson ldquoAssessing impacts of Landuse and Landcoverchanges on hydrology for the upper San Pedro watershedrdquoJournal of Hydrology vol 407 no 1ndash4 pp 105ndash114 2011

[10] Y Wang W Ji X Yu et al ldquoThe impact of urbanization onthe annual average temperature of the past 60 years in BeijingrdquoAdvances in Meteorology vol 2014 Article ID 374987 9 pages2014

[11] Y Li J Fan Z Hu Q Shao L Zhang and H Yu ldquoInfluence ofland use patterns on evapotranspiration and its components ina temperate grassland ecosystemrdquo Advances in Meteorology Inpress

[12] X Yao Z Wang and H Wang ldquoImpact of urbanization andland-use change on surface climate inmiddle and lower reachesof the Yangtze River 1988ndash2008rdquo Advances in Meteorology Inpress

[13] M Lopez-Vicente J Poesen A Navas and L Gaspar ldquoPredict-ing runoff and sediment connectivity and soil erosion by waterfor different land use scenarios in the Spanish Pre-PyreneesrdquoCatena vol 102 pp 62ndash73 2013

[14] N Ohana-Levi A Karnieli R Egozi A Givati and A PeetersldquoModeling the effects of land-cover change on rainfall-runoffrelationships in a semi-arid EasternMediterranean watershedrdquoAdvances in Meteorology In press

[15] G Wang H Yang L Wang Z Xu and B Xue ldquoUsing theSWAT model to assess impacts of land use changes on runoffgeneration in headwatersrdquoHydrological Processes vol 28 no 3pp 1032ndash1042 2014

[16] X Li ldquoA review of the international researches on land uselandcover changerdquo Acta Geographica Sinica vol 51 no 6 pp 553ndash558 1996

[17] Q F Zhang F Q Wu L Wang L Yuan and L-S ZhaoldquoApplication of PCA integrated with CA and GIS in eco-economic regionalization of Chinese Loess Plateaurdquo EcologicalEconomics vol 70 no 6 pp 1051ndash1056 2011

[18] C Shi Y Zhou X Fan and W Shao ldquoA study on the annualrunoff change and its relationship with water and soil conser-vation practices and climate change in the middle Yellow Riverbasinrdquo Catena vol 100 pp 31ndash41 2013

[19] J Zhang ldquoComprehensive treatment for large basin and har-monious development of upstream and downstream-survey oncomprehensive harness engineering of soil and water conserva-tion for upper Fenhe Riverrdquo Shanxi Water Resources vol 21 no4 pp 5ndash9 2005

[20] X Wang and X Nie ldquoAnalysis on the benefit of soil and waterconservation in the upper-reach of Fenhe reservoir-a case studyof comprehensive management to Fenhe during the secondphase in Jingle countyrdquo Journal of Shanxi Agricultural University(Social Science Edition) vol 6 no 3 pp 237ndash240 2007

[21] B Yang ldquoViewing the function of integrated treatment of soiland water conservation conducted in the upper Fenhe Riverfrom sediment discharge variations at Jingle hydrometric sta-tionrdquo Soil and Water Conservation in China no 10 pp 32ndash342007


[22] WMeng SWang and J Niu ldquoUpstream Fenhe River the Basinhumanity moves under the forest cover changerdquo Journal ofTaiyuan Normal University (Natural Science Edition) vol 6 no1 pp 75ndash79 2007

[23] Z Li W-Z Liu X-C Zhang and F-L Zheng ldquoImpacts of landuse change and climate variability on hydrology in an agri-cultural catchment on the Loess Plateau of Chinardquo Journal ofHydrology vol 377 no 1-2 pp 35ndash42 2009

[24] H Li Y Zhang J Vaze and B Wang ldquoSeparating effects ofvegetation change and climate variability using hydrologicalmodelling and sensitivity-based approachesrdquo Journal of Hydrol-ogy vol 420-421 pp 403ndash418 2012

[25] J G Arnold R Srinivasan R S Muttiah and J R WilliamsldquoLarge area hydrologic modeling and assessment part I modeldevelopmentrdquo Journal of the American Water Resources Associ-ation vol 34 no 1 pp 73ndash89 1998

[26] J Sun Y Liu Y Wang G Bao and B Sun ldquoTree-ring basedrunoff reconstruction of the upper Fenhe River basin NorthChina since 1799 ADrdquo Quaternary International vol 283 pp117ndash124 2013

[27] XWang ldquoStudies on ecology and environment improvement ofFenhe reservoir and its upstream water sourcesrdquo China WaterResources vol 16 pp 44ndash47 2008

[28] S Neitsch J Arnold J Kiniry J Williams and K King SoilandWater Assessment ToolTheoretical Documentation Version2005 Texas AampM University College Station Tex USA 2005

[29] Z Lu S Zou Z YinA Long andBXu ldquoAnew suitablemethodfor SWAT model calibration and its application in data-scarcebasinsrdquo Journal of Lanzhou University (Natural Sciences) vol48 no 1 pp 1ndash7 2012

[30] D N Moriasi J G Arnold M W Van Liew R L Bingner RD Harmel and T L Veith ldquoModel evaluation guidelines forsystematic quantification of accuracy inwatershed simulationsrdquoTransactions of the ASABE vol 50 no 3 pp 885ndash900 2007

[31] J Franczyk and H Chang ldquoThe effects of climate changeand urbanization on the runoff of the Rock Creek basin inthe Portland metropolitan area Oregon USArdquo HydrologicalProcesses vol 23 no 6 pp 805ndash815 2009

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Mining


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Geological ResearchJournal of


Geology Advances in


Wang et al (2014) assessed the impacts of land use changes onevapotranspiration quickflow infiltration and baseflow inthe upstream regions of the Three Gorges reservoir in China[15] Assessing impacts of land use and land cover (LULC)changes on hydrology is essential for watershed managementand ecological restoration [7 15 16]

In general regional impacts of land use change onhydrology vary from place to place and need to be consideredfor specific circumstances and environments [15 16] TheLoess Plateau of western China is infamous for serious soilerosion and is the main source of sediment in the middlereaches of the YellowRiver and has become the focus of worldattention As early as the 1950s China started soil and waterconservation works on the Loess Plateau in order to improvethe local environment and mitigate sediment accessions tothe middle reaches of the Yellow River and works wereexpanded after the 1970s [17 18] As a consequence land usein the Loess Plateau has undergone great changes Likewisein the past century a range of management measures werecarried out in the Fenhe River Basin on the eastern marginof the Loess Plateau Some research has been done onthe impacts of land use change on basin hydrology [19ndash22] but research on the contribution of individual LULCto the total runoff and the impacts of LULC changes onwatershed hydrology is lacking In particular there is a lackof information for evaluating the benefits of soil and waterconservation in the Fenhe River basin and the whole of theLoess Plateau where it is difficult to distinguish the impactsof LULC changes on hydrology Greater understanding ofthe contribution of individual LULC change to runoff andthe impacts of LULC changes on the hydrology at differentscales is needed to guide comprehensive natural resourcesmanagement in this region

Methods for assessing hydrological impacts of land usechanges in watersheds include comparisons of paired catch-ments statistical analysis and hydrological modeling [523 24] Among these approaches hydrological modelingis the most suitable one for use in scenario studies atdifferent scales Widely used hydrological models in stud-ies on the impacts on watershed hydrology include theHydrologic Simulation Program FORTRAN the Soil andWater Assessment Tool (SWAT) and WaTEMSEDEM [45 9 15] The SWAT model is widely used to assess hydrol-ogy and water quality in agricultural catchments aroundthe world (httpswwwcardiastateeduswat articles) It isreadily available and user-friendly for data input [25]

The overall objectives of this study are to investigate thecontributions of individual LULC change to runoff and todetermine the impacts of LULC changes on the hydrology ofthe Upper Fenhe River watershed by an integrated approachthat combines hydrological modeling and remotely senseddigital maps of LULC changes To avoid the impacts of large-scale water resource development projects on hydrologicalprocesses particularly the water diversion project from theYellow River to Fenhe River at Wanjiazhai in the study areaafter 2002 the period from 1990 to 2000 was selected as thestudy period during which sufficient data are available Thespecific objectives are (1) to investigate the LULC changes ofthewatershed from 1995 to 2010with LULCmaps determined

by remote sensing images in 1995 and 2010 (2) to calibrateand validate the SWATmodel in terms ofmonthly streamflowbased on the DEM soil map land use in 1995 and climatedata from 1990 to 2000 (3) to assess the hydrological effects ofindividual land uses and (4) to simulate responses of hydro-logic components to land use changes at basin and subbasinscales under the same climatic conditionsThe results shouldassist decision-makers in target water resources planning andvegetation restoration on the Loess Plateau

2 Study Area

The Fenhe River is located in the eastern part of the LoessPlateau North China and runs north to south throughalmost all of Shanxi Province [26]The study area is theUpperFenhe River watershed above the Hecha hydrological controlstation which measures the amount of water and sedimententering Fenhe reservoir (Figure 1) The Upper Fenhe Riverwatershed has an area of about 3242 km2 and lies betweenlatitudes 38∘001015840 and 39∘001015840 and longitudes 111∘401015840 and 112∘401015840Elevations in the basin range from 1124 to 2762m andit has an arid to semiarid climate with a mean annualprecipitation of 430mm The precipitation is concentratedbetween the months of June and September and accounts forapproximately 70 of total annual precipitation coming inthe form of high-intensity storms that often cause extremesoil erosion The average annual temperature is 90∘C witha minimum average temperature of minus5∘C in winter anda maximum average temperature of 20∘C in summer Theland use classes of the watershed include farmland forestgrassland water or wetland built-up land and unused landtheir percentages in 2010 were 30 283 3957 139073 and 001 respectively The region is covered withhighly erodible loess-derived soils Major soil series includeloess soil cinnamon soil brown soil and calcium skeletal soil

3 Methodology

A conceptual framework consisting of three stages was devel-oped (Figure 2) (1) transition matrix analysis to describethe transformations of land use from 1995 to 2010 (2)hydrological modeling to simulate hydrological componentsfor two LULC maps under the same climatic conditions and(3) comparison of the contribution of each land use class tothe watershedrsquos water yield and their hydrological effects onsubbasins

31 Transition Matrix The transition matrix of land usechange was calculated as

119861

119894119895=

[

[

[

[

[

[

[

119861

11119861


1119899

119861

21119861


2119899

sdot sdot sdot

119861

1198991119861


119899119899

]

]

]

]

]

]

]

(1)

where 119861 is the area of a certain kind of land use 119899 is thenumber of land use types in the study area 119894 and 119895 (119894 119895 =1 2 119899) are the types of the land use before and after


0 10(km)

0 200100(km)

20

7

2

1014

1

22

11

21

13

27

6

29

1712

28

25

32 30

3637

38

26 24

1815

23

1619

3 89

4 5

33 35


Hecha

Jingle

Fenhe reservoir

20

Taiyuan

Fenhe

Fenhe River basin

River

BeijingS

E

N

W39∘0998400N

38∘40998400N

38∘20998400N

38∘0998400N

111∘40

998400E 112∘0998400E 112

∘20

998400E

DEM27621126

(m)




DEM





Scenarios analysis













Hecha




1990ndash2000








Calibrationperiod

Validationperiod










Forest

N1995 2010




1995

Farmland 90826 1774 7966 113 699 029 101407Forest 968 84049 4588 048 082 002 89737


Total 97296 91744 128298 4502 2356 039 324235








150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month



Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)








3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


0 10(km)

0 200100(km)

20

7

2

1014

1

22

11

21

13

27

6

29

1712

28

25

32 30

3637

38

26 24

1815

23

1619

3 89

4 5

33 35


Hecha

Jingle

Fenhe reservoir

20

Taiyuan

Fenhe

Fenhe River basin

River

BeijingS

E

N

W39∘0998400N

38∘40998400N

38∘20998400N

38∘0998400N

111∘40

998400E 112∘0998400E 112

∘20

998400E

DEM27621126

(m)




DEM





Scenarios analysis













Hecha




1990ndash2000








Calibrationperiod

Validationperiod










Forest

N1995 2010




1995

Farmland 90826 1774 7966 113 699 029 101407Forest 968 84049 4588 048 082 002 89737


Total 97296 91744 128298 4502 2356 039 324235








150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month



Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)








3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in





Hecha




1990ndash2000








Calibrationperiod

Validationperiod










Forest

N1995 2010




1995

Farmland 90826 1774 7966 113 699 029 101407Forest 968 84049 4588 048 082 002 89737


Total 97296 91744 128298 4502 2356 039 324235








150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month



Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)








3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in




Forest

N1995 2010




1995

Farmland 90826 1774 7966 113 699 029 101407Forest 968 84049 4588 048 082 002 89737


Total 97296 91744 128298 4502 2356 039 324235








150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month



Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)








3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in




150

120

90

60

30

01992-1 1994-1 1996-1 1998-1 2000-1 2000-12

Month



Mon

thly

runo

ff(m

3 s) NSE = 092

R2= 092

PBIAS = minus1

NSE = 085

R2= 090

PBIAS = minus9

(a)

1992-1 1994-1 1996-1 1998-1 2000-1 2000-12Month


150

120

90

60

30

0

Mon

thly

runo

ff(m

3 s) NSE = 091

R2= 093

PBIAS = minus12

NSE = 089

R2= 089

PBIAS = minus6


(b)








3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in


3925

2768

3128

041138


283

3957

139074

30


074117

2148

3878

3783




3787

074203

2093

3843



















5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in










5 Conclusions









Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in







Acknowledgments


References










































Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in





















Volume 2014

Mining


Journal of



Geophysics







Journal of




Advances in











Geology Advances in

Research Article Hydrologic Responses to Land Use Change...

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Transcript of Research Article Hydrologic Responses to Land Use Change...