Modelling surface energy fluxes based on multi-temporal remote sensing data at different scales

摘要

The Surface Energy Balance Algorithm for Land (SEBAL) is a widely accepted and valid method to model actual evapotranspiration (ET_(act)). This study focuses on impacts of different preprocessing routines and different sensor data on SEBAL output data. The model was applied to scenes contemporaneously recorded by ASTER and MODES. Two input parameters, LST and albedo (α), one intermediate modeling output, net radiation (R_n) and the resulting ET_(act) were exemplarily investigated at both scales. The study area was the irrigation system of the Khorezm region, Uzbekistan.Varying agreements among the parameters themselves and the different acquisition dates were found. LST showed similar value ranges for both sensors, but scattered differently. In comparison to ASTER derivatives, a systematic underestimation of MODES a consequently resulted in overestimations of R_n. Comparisons of the ET_(act), finally demonstrated the necessity to adjust field conditions assumed at the anchor points of the SEBAL model to the pixel size of the respective sensor.