Estimation of area-averaged evapotranspiration in ejina oasis base on EC matrix flux measurements and footprint analysis

The acquisition of area-averaged evapotranspiration (ET) over complex land surfaces is crucial to develop ET estimation models and improve the accuracy of remote sensing ET products. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) flux matrix located in Ejina oasis provided a unique opportunity to apply an aggregation scheme for area-averaged fluxes. Based on HiWATER flux matrix observations in Ejina oasis and a high-resolution land cover map, the area-averaged ET over the Sidaoqiao kernel experimental area in Ejina oasis was estimated using a flux aggregation method that had been built with footprint analysis and multiple regression analysis. The results showed that the refined flux integration technique used in this study is a potential method for the determination of area-averaged fluxes over heterogeneous surface fluxes.