Improvements of regional evapotranspiration model by considering topography correction

摘要

A remote sensing regional evapotranspiration (ET) model was built on the basis of topography correction (slope, aspect and elevation), herein. A variety of satellite data which have visible, near-infrared and thermal infrared remote sensing data can be used by this improved model. Combined with conventional ground meteorological information, it can estimate regional distribution of ET under different climate and terrain conditions, expanding the scope of application. This research indicates that application of medium or high resolution satellite data to calculate regional ET under undulating landform should consider the impact of terrain. The analysis of the impact of the ET results simulated by the model in combination with terrain factors (altitude, slope, aspect) show that the ET results will overestimate about 30% in high altitude and shady slope region if the terrain is not taken into account. It improves the accuracy of ET estimates and has important reference value for the work of the regional water balance and regional agricultural climate research.