中文摘要：

区域蒸腾蒸发量是重要的地表水分运动过程，水土保持措施改变了下垫面特征，从而影响了这一过程。为了揭示不同水土保持措施下的区域蒸腾蒸发特点，本文选取黄土高原丘陵沟壑区韭园沟治理流域以及其对比流域裴家峁，运用基于能量平衡原理的SEBAL遥感模型，计算了不同下垫面的蒸散发量，结果表明：研究区地表反照率多集中于0．1—0．2之间；不同水土保持治理度下的流域归一化植被指数NDVI呈现出不同的季节变化特点；净辐射集中在400—800Wm^-2，感热通量集中在50～200Wm12之间，土壤热通量集中在100—200Wm^-2之间；治理度高的韭园沟流域日蒸腾蒸发量略小于裴家峁流域，不同土地利用类型下的日蒸腾蒸发量顺序为坝地〉果园及林地〉草地〉梯田〉坡耕地。文章最后，作者从多个角度对计算结果的合理性进行了分析，表明SEBAL模型估算的流域蒸散发是可信的。

英文摘要：

Watershed evapotranspiration is an important process of surface water movement. Water and soil conservation measures influence this process by altering properties of the underlying surface. To reveal evaportranspiration characteristics of watersheds different in adoption of water and soil conservation measures, two watersheds, Jiuyuangou and Peijiamao in a hill-gully region of the Loess Plateau, were selected as subjects for estimation of evapotranspiration from different underlying surfaces using the energy balance based SEBAL remote sensing model. Results show that the surface albedo of the study area varied mostly in the range of 0.1 - 0.2 ; the NDVI of the watershed under different water and soil conservation managements displayed different seasonal variation; the net radiation fluctuated in the range of 400 -800W m-2, the sensible heat flux of 50 - 200W m-2, and the soil heat flux of 100 - 200W m-2 ; the daily evaportranspiration of Jiuyuangou, which is better managed in water and soil conservation, is slightly less than that of Peijiamao. Lands different in land use followed the order of check dam 〉 orchard 〉 woodland 〉 grassland 〉 terrace 〉 slope land in daily evaportranspiration. Analysis of rationality of the calculation from various angles suggests that the estimation of watershed evapotranspiration using the SEBAL model is reliable.