Estimation of Actual Evapotranspiration by Complementary Theory-Based Advection-Aridity Model in the Tarim River Basin, China

AbstractIn this study, the complementary relationship between actual evapotranspiration (ETa) and potential evapotranspiration (ETp) was verified in the Tarim River basin (TRB) in northwest China. The advection-aridity (AA) model that is based on the complementary relationship (CR) was used to calculate ETa. Spatial and temporal trends in the estimated annual ETa and the factors that influenced ETa were investigated. The multi-year average ETa in the TRB for the period from 1961 to 2014 was 178.5 mm. There was an overall significant increasing trend (at a rate of 10.6 mm/10a) in ETa from 1961 to 2014; ETa increased at a rate of 22.9 mm/10a from 1961 to 1996 and decreased at a rate of 33.9 mm/10a from 1996 to 2014. Seasonally, ETa was strongest in summer, followed by spring and autumn. The spatial distributions of the annual and seasonal ETa were mostly consistent, with higher ETa values in the northeast, northwest and southwest of the TRB, and lower ETa values in the mostly desert lands in the central and...