Abstract:
In this study,a satellite remote sensing model of deducting sensible heat from surface energy balance algorithm for land(SEBAL)is used. The regional distribution maps of the daily evapotranspiration(ET)during April to August over the eastern part of Northwest China(33-38°N,102-108°E)is estimated,combining NOAA-16 AVHRR data with the microme teorological observations over a wheat field at Dingxi arid meteorological and ecological environment experimental station and regular observations data of 127 weather stations. Based on land use,we evalute the average and standard deviat ion of the de rived ET for irrigate fields,short grass,spring and winter wheat rainfed fields,pine and broadleaf forest,evergreen forest and marsh fields. It is shown that the ET distribution feature is decreasing from the south humid evergreen forest though the semiarid rainfed agriculture region to the north arid desert during the variant plants growing periods. The mean relative error (MRE)is 16.6% evaluated through the derived ET and the measured values estimated using the evaporation dish at 54 stations. The MRE is only 16.2% between the derived results and the measured of L1 7500 CO
2/H
2O gas analyzer at Dingxi station The results show that the derived results is in good agreement with measured values over experimental regions.