Spatial And Temporal Distributions Of Evapotranspiration In Zhejiang Province Based On MODIS Data

The evapotranspriration (ET) of land surface is an important part of the water budget in soil-air interaction. This study derived the regional ET of Zhejiang province on April2, August2, November4th, and December18th,2006, using the new generation earth observation data MODIS, on the basis of SEBAL modal, which is based on the principle of surface energy balance, and analyzed the spatial distribution of some important characteristic surface land parameters like NDVI, surface albedo, land emissivity and land surface temperature. The error of land surface temperature was analyzed by contrasting with data of homologous MODIS product; as to ET, it was verified by comparing with the data estimating by FAO-PM method, in the situation of lacking observed ET.It can be found that ET has remarkably spatial and temporal differences by analyzing the spatial distribution map of ET. In the matter of time, the ET values in summer, which can come to above ten millimeter, are greater than those in other seasons due to higher temperature; In the matter of space, the ET values are relatively high in the places of plenty of surface water, high temperature or strong wind. The result of study shows that it is feasible to derive regional ET by method of remote sensing. Deriving ET on the basis of remote sensing can provide the necessary support of spatial data for the research on hydrology and water resource at large scale.