Estimation and Validation of Land Surface Evaporation Using Remote Sensing and Meteorological Data in North China

Estimation and Validation of Land Surface Evaporation Using Remote Sensing and Meteorological Data in North China

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

There is a growing interest in quantifying regional scale actual evapotranspiration (ET) for water resource management. Using moderate-resolution Imaging spectroradiometer (MODIS) data, in combination with meteorological records, an integrated approach is proposed to estimate daily ET over 1-km grid covering North China. The Surface Energy Balance System (SEBS) is adapted to partition the sensible heat from latent heat. A gap-filling method for ET estimation during cloudy intervals is accomplished by a combination of SEBS outputs and Penman-Monteith equation. The proposed scheme, named ETWatch, is calibrated and evaluated using measurements from four flux sites in the semi-humid regions with different soil types, land cover, and climate conditions in North China. The gap-filling method reproduces observed fluxes with satisfied correlation, yielding about a 22% MAPD in Yucheng agriculture site. The improved method could be used to study the impact of different agricultural water consuming patterns in North China.