Regional ET Estimation with Remote Sensing
Evapotranspiration (ET) is of great significance for water resources management and planning. Remote sensing can provide surface parameters for ET estimation at regional scale, whereas traditional approaches just provide points measurement. This paper introduces an ET monitoring system using remote sensing (ETWatch), an operational processing chain starting from data pre-processing to application products, utilizing spatial information on climate, soil type, land use, vegetation cover,digital elevation, and remote sensed land surface parameters. SEBAL and SEBS are integrated into ETWatch to estimate surface fluxes on clear-sky condition. The model of surface resistance, which is introduced in the method of Evapotranspiration(ET) with remote sensing, is to fill solve the image gaps because of the cloud and remote sensing data quality. And then Penmon-Monteith is applied to retrieved daily ET base on the time series of surface resistence data and daily meteorological data. The application of ETWatch in Hai Basin was demonstrated for year 2002 to 2005, and a validation is carried by comparing field fluxes measurement and hydrological record with model estimation. The results show that when the energy closure ratio (ECR) of Eddy covariance (EC) technique is above 0.9, average deviation of daily ET(lkm) is below 10%; at the field scale(30m), compared to water consumption from soil-moisture-depletion-method, average deviation of remote sensed daily crop ET is about 12.7%.
Evapotranspiration remote sensing monitoring system surface resistance model
WU Bingfang SUN Minzhang YAN Nana
Institute of Remote Sensing Applications, Chinese Academy of Sciences Beijing, BOX 9718, 100101, P.R China Irrigation and Drainage Center, Minister of Water Resources, Beijing 100052,China
国际会议
北京
英文
187-192
2008-12-08（万方平台首次上网日期，不代表论文的发表时间）