Remote Sensing Derived Evapotranspiration Data to Calibrate SWAT Model: A Case Study of Big Sunflower River Watershed, Mississippi Delta.

Abstract.

This study will apply an evapotranspiration (ET) time series derived from remote sensing to calibrate SWAT crop model by minimizing the parameter equifinality. The Soil and Water Assessment Tool (SWAT) hydrologic model was calibrated and validated at the Big Sunflower River Watershed (BSRW; 7,660 km²) in Northwestern, Mississippi. The SWAT crop model was calibrated and validated for corn and soybean yield with the absence of the ET data and compares the model output ET with the ET derived from MODIS data. Surface energy balance algorithm for land (SEBAL) was used to generate monthly ET time series data using MODIS images for a period from 2007 to 2008. The SWAT crop model was further calibrated using MODIS ET and compared the results to evaluate the effects of MODIS ET on SWAT crop model performances. The models simulated results for both scenarios will be evaluated statistically using mean, coefficient of determination (R²) and root mean square error (RMSE) with observed corn and soybean yields. The results of this study will be useful to determine water budget parameters using a modeling approach.  

 

Keywords. Evapotranspiration, MODIS, crop yield, SWAT, remote sensing.