利用SEBAL模型对沙拉沐沦河流域蒸散发的分析  

Study on Evapotranspiration in the Shalamulun River Basin Using SEBAL Model and MODIS Data

作　　者：杨肖丽[1] 任立良[1] 袁飞[1] 雍斌[1] 江善虎[1] 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098

出　　处：《干旱区研究》2010年第4期507-514,共8页Arid Zone Research

基　　金：国家重点基础研究发展计划973项目(2006CB400502;高等学校学科创新111引智计划项目(B08048)

摘　　要：以2001年7月10日的MODIS数据为数据源,采用基于地表热量平衡的SEBAL模型估算位于半干旱地区的沙拉沐沦河流域的实际蒸散发量,综合分析蒸散发量与土地利用/覆被、地表温度、植被指数、高程、坡度和坡向的关系。结果表明:该流域的夏季日实际蒸散发量空间差异比较大,从0mm到6.57mm,平均蒸散发约2.90mm;蒸散发的空间分布不均匀,流域边缘林地覆盖区的蒸散发最高,中部和流域出口所在的草地、耕地分布区相对较低。实际蒸散发量与地表温度和归一化植被指数高度线性相关;不同的土地利用类型具有不同的日平均蒸散发量,林地的日平均蒸散发量最高,其次为耕地,建设用地最低。Apart from rainfall and runoff,evapotranspiration （ET） including water evaporation from soil surface and vegetation transpiration represents a fundamental process of hydrological cycle and a key element of water resources management,particularly in semiarid and arid regions,because it affects the partition of energy and water fluxes over earth surface.ET is one of the important components of hydrological cycle in semiarid regions and cannot be directly measured.Estimate of regional ET is of a crucial need for climate studies,weather forecasts,hydrological surveys,ecological monitoring,and water resources management.Traditionally,ET is computed as a residual in water balance equations,from estimates of potential ET or,indirectly,from field measurements at meteorological stations.Recently,however,some researchers have begun to use scintillometers,RS data and hydrological models to estimate regional ET.The current study focuses on deriving daily actual ET values from Moderate Resolution Imaging Spectroradiometer （MODIS） images over the Shalmulun River Basin in Inner Mongolia,China.The SEBAL model based on the Surface Energy Balance Algorithm for Land is applied in this study.In this model,a small number of empirical relations are needed only,and there are also many other advantages.In the SEBAL model,surface albedo,NDVI and surface temperature could be derived from RS data.Semi-empirical relationships are used to estimate the emissivity from Normalized Difference Vegetation Index （NDVI）.The atmospheric transmittance and atmospheric emissivity could be estimated from meteorological data,such as air temperature and humidity.Elevation,slope and aspect of land surface could be extracted and computed from the digital elevation model （DEM）.Landsat Enhanced Thematic Mapper Plus （ETM＋） images in July 6,2001 are used to detect the land use/cover types in the study area.The spatial distribution of daily ET in the study area is estimated.In addition,the effects of surface temperature,NDVI,elevation,slope,

关 键 词：蒸散发量 空间分布 SEBAL模型 植被指数 土地利用类型 沙拉沐沦河流域 半干旱区 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]