REMOTE SENSING OF ACTUAL EVAPOTRANSPIRATION AT BASIN SCALE IN THE NORTHERN TIBETAN PLATEAU AREA

摘要

Evapotranspiration(ET), as one of the most uncertain components of the water cycle, was derived in the Nagqu river basin of the northern Tibetan Plateau based on multi-sensor remote sensing data and field observations under clear-sky condition. Improved land surface albedo, improved downward shortwave radiation flux and reconstructed normalized difference vegetation index (NDVI) were coupled into the topographical enhanced surface energy balance system (TESEBS) model to estimate actual ET. The model-estimated results were compared with those determined by the combinatory method which were treated as actual ET. The results indicated that the model-estimated ET agreed well with actual ET with correlation coefficient, mean bias error and root mean square error of 0.836, 0.087 and 0.140 respectively.