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The estimation of surface evapotranspiration (ET) with satellite dataset is one of the main subjects in the understanding of climate change,disaster monitoring and the circulation of water vapor and energy in Tibet Autonomous Region (TAR).This research selects satellite images on January 11,April 6,July 31 and October 19 in 2010 as the representative of winter,spring,summer and autumn respectively,estimates the distribution of daily surface ET based on the surface energy balance system (SEBS) along with potential evapotranspiration (PET) and ET derived from Penman-Monteith (P-M) method.The results are obtained as follows.(1) The seasonal distribution of ET and PET basically decreases from the southeast part to the northwest part of TAR.Though ET or PET have similar spatial distributions,there are still exists some difference to estimate the extreme values especially the maximum value in the middle and southeastern parts of TAR.No matter what kind of methods we taken,the maximum value of ET and PET always appears in summer,followed by autumn or spring while that in winter is smallest.