THE REMOTE SENSING MODEL FOR REGIONAL EVAPOTRANSPIRATION ESTIMATION OVER HETEROGENEOUS LANDSCAPE

It is a very complicated problem to estimate evapot ranspiration over natural land surface.In this paper,the evapot ranspiration estimation models for dense vegetation and bare soil are presented based on the information of surface parameters firstly:These models are based on information from surface properties like land cover and surface albedo.Then by use of vegetation fraction(the ratio of vegetation projective area to unit area),the regional evapot ranspiration estimation model over the heterogeneous landscape is proposed.As a result of case study over North China,it shows that the accuracy of evapotranspiration estimation is higher and the features of evapot ranspiration over North China are discussed.The validation shows that this model provides good estimation of daily regional ET.