Remote Sensing and the SEBAL Model for Estimating Evapotranspiration in the Tarim River

The paper estimates evapotranspiration of the mainstream by using remote sensing data in 1985,2000,and 2010 respectively and SEBAL model in the mainstream of Tarim River.The results show that evapotranspiration in the area ranges from 0 to 5.11 mm /d;the evapotranspiration of the area close to the river was significantly higher than the area away from the river;the land use types associated with evapotranspiration are listed in the order of water bodies farmland woodland grassland unused land home-work sites,which is mainly related to its vegetation coverage and water supply;the total daily evapotranspiration islisted in the order of grassland unused land farmland forestland water bodies home-work sites,which are closely related to the land use types.During 1985-2010,the total daily evapotranspiration in the Tarim River basin decreased firstly and then increased;the average total daily evapotranspiration in the upstream is 1.27 times that of the middle-stream and is 1.42 times that of the lower-stream.The total evapotranspiration in the Tarim River basin in 2000 decreased by 6.80×104 m3 compared with in 1985,because the total daily evapotranspiration in the middle and lower reaches decreased while the upper reaches increased by 3.02×105 m3.The total daily evapotranspiration in the mainstream of the river in 2010 is 6.78×105 m3 higher than that in 2000,with the upper and middle reaches up by 1.19×106 m3 and the lower reach down by 5.16 × 105 m3,which is mainly due to the fact that rapid expansion of cultivated land and excessive exploitation of water resources in the middle and upper reaches resulted from water decrease in the downstream.