An evapotranspiration (ET) model based GIS using LANDSAT data and MODIS data with improved resolution

摘要

In this work, we integrate a popular remote sensing technique with ArcGIS to build a tool bar, named rGIS-ET, for estimating regional evapotranspiration (ET) from Landsat data and MODIS data with improved resolution. The development of rGIS-ET enables quick processing of large amount of remote sensing and other spatial data. It also provides user-friendly interfaces for modelling, output display and result analyses. Both surface temperatures and albedo were key parameters for calculating ET using Surface Energy Balance Algorithm. We adopted algorithms for estimating surface temperatures and albedo of winter wheat and summer maize field from MODIS data at 250 m spatial resolution to improve the resolutions of ET map of MODIS. We apply improved rGIS-ET to eight plain counties of Shijiazhuang city, a typical agricultural region in North China Plain, to demonstrate its utility for calculating regional ET and evaluating agriculture water resource usage. The improved ET map of MODIS could represent the spatial variation of crop ET much better than that without improved.