基于遥感和SEBAL模型的塔里木河干流区蒸散发估算

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

运用1985年、2000年和2010年遥感资料与SEBAL模型估算了塔里木河干流区蒸散发。结果表明:该区蒸散发量较大,介于0～5.11mm/d之间;靠近河道区蒸散发明显大于远离河道区;各土地利用/覆被类型蒸散发大小依次为:水体>耕地>林地>草地>未利用地>居工地,主要与其植被覆盖度和水分供给条件有关;而日总蒸散发大小顺序为:草地>未利用地>耕地>林地>水体>居工地,这与各土地利用/覆被类型面积密切相关。在1985-2010年间,塔里木河干流区日总蒸散发量先减小后增大;上游平均日总蒸散发量为中游和下游的1.27倍和1.42倍。2000年塔里木河干流区日总蒸散发比1985年减少了6.80×104m3,原因是中游和下游日总蒸散发减小,而上游日总蒸散发量却增加了3.02×105m3。2010年干流区日总蒸散发比2000年高6.78×105m3,其中上游和中游日总蒸散发量增加了1.19×106m3,而下游却降低了5.16×105m3,主要受中上游地区绿洲耕地面积扩张,水资源开发量过大,下游来水量减少的影响。

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.