Spatial-temporal inversion of evapotranspiration in the Weihe River Basin and its response to human activities
[Objective]Human activities such as land use change,land engineering construction,and industrial and agricultural production have an important impact on surface evapotranspiration by changing the underlying surface properties,but the quanti-tative research on human driving forces is currently very limited.[Methods]Based on MODIS remote sensing images and meteor-ological data,the Surface Energy Balance System(SEBS)model and trend analysis method are used to explore the spatiotemporal evolution characteristics of evapotranspiration in the Weihe River Basin over a long time series from 2009 to 2019,and the response of evapotranspiration to human activities is quantitatively evaluated using the residual analysis method.[Results]The result showed that:(1)The fitting coefficients(R2),root-mean-square error(RMSE),and mean relative error(MRE)of evapotranspiration(ET)estimated by the SEBS model to the measured values obtained by the water balance method are 0.78,0.84 mm,and 34.1％,respectively.(2)From 2010 to 2018,the net decrease of cultivated land in the Weihe River Basin is about 1 622.5 km2,with a growth rate of-2.91％,mainly flowing into grassland;the net increase of construction land area is about 785.75 km2,with a growth rate of about 15.55％,mainly flowing into cultivated land,and the unused land had the least transfer.(3)The area where human activities have a promoting effect on ET in the Weihe River Basin accounts for about 45.41％of the total area,with the area where the contribution rate is above 80％accounting for about 30％;the area where hu-man activities have a suppressing effect on ET accounts for about 4.24％,with the contribution rate in the Guanzhong area above 80％.[Conclusion]The result show that:(1)The SEBS model has good applicability in the study area.(2)On the time scale,the actual evapotranspiration shows a fluctuating upward trend year by year,with a change rate of about 0.019 mm/a;on the spa-tial scale,the actual evapotranspiration shows a zonal distribution pattern of high in the southeast and low in the northwest.(3)During the study period,human activities has different driving effects on surface evapotranspiration,with the areas where evapo-transpiration is promoted mainly distributed in the middle reaches of the Jinghe,Beiluohe rivers and some areas upstream of the Weihe River,and the areas where evapotranspiration is suppressed mainly distribute in the Guanzhong area.
evapotranspirationhuman activitiesSEBS modelresidual analysisWeihe River Basin
国家科技期刊平台
NSTL
万方数据
维普
