干旱区黑河流域复杂地表蒸散量遥感研究

在全球水资源日益匮乏的情况下，利用遥感技术估算区域蒸散量为合理利用和分配水资源提供了一种快捷有效的方法。目前基于地表能量平衡的卫星遥感蒸散模型日益成熟，在这一背景下，充分利用以往在黑河地区开展的遥感模拟研究成果，针对西北干旱区黑河流域复杂地形特点，估算了该流域2004年度的蒸散量并给出了在不同土地利用条件下蒸散分布的数量差异。结果表明，流域年蒸散总量估算值在整个流域及其上、中、下游各予区域上，基本满足水文学区域水量平衡关系。同时应该指出，在地表景观分异强烈的地区，采用中分辨率遥感资料会对地表“混合像元”观测存在“平均”作用导致蒸散量的低估。

Estimation of Evapotranspiration from Satellite Remote Sensing Data over the Complex Terrain of the Arid Hei River Basin of Northwestern China

Under the condition that the global water resource is increasingly short of, evapotranspiration （ET） estimated by remote sensing techniques provide a kind of fast and valid method to make use of and assign the water resource reasonably. Now the existing remote sensing ET schemes based on land surface energy balance method is becoming ripe, and exactly under this background this paper took full advantage of the former research results over the Hei River Basin and estimated the total ET amount in 2004 aiming at the complex terrain characteristics of this area and compared the differences of ET amount under the different land use conditions. The analysis shows that the water balance rela- tionship is basically satisfied by the derived regional ET either over the entire basin area or over different partial regions from the upper to the middle and lower reaches of Hei River Basin. There is need to note that the ET derived from MODIS data may be underestimated due to ＂aver- age＂ effect of MODIS sensor on land surface properties over the region with strong spatial variation of landscape.