LAUSR

Abstract Runoff is an important factor in maintaining the normal operation of wetland ecosystems. An effective runoff simulation can provide an important decision basis for wetland protection and ecological restoration. Aiming to make the spatial resolution of remotely sensed precipitation products match the existing high-precision digital elevation model (DEM), this study used multiple linear regression (MLR) and geographic weighted regression (GWR) methods to build a downscaling correction method for precipitation products in the Qixing Wetland Watershed. The TRMM 3B42V7 data were downscaled from 0.25° × 0.25° to 0.05° × 0.05°. Compared with the downscaling correction of the nearest neighbor method, the GWR correction performed better and could noticeably reduce the average relative deviation between the corrected precipitation series and the measured precipitation series and increase the correlation coefficient of the two series. For the MLR correction, the two indicators (the average relative deviation and the correlation coefficient) improved slightly. The downscaled precipitation data were input into the semidistributed hydrological model. The flood simulation results revealed that the GWR-corrected rainfall data could improve the accuracy of flood simulation better than the MLR.