Abstract
The Integrated Flood Analysis Model (IFAS), a distributed hydrological model, developed by the International Center for Water Hazard and Risk Management (ICHARM) was utilized to assess runoff from a flood event using two satellite-based rainfall products: Global Satellite of Mapping Precipitation (GSMaP): Near Real Time (NRT) and Tropical Rainfall Measuring Mission (TRMM):3B42RT V7. The devastating Thailand flood of 2011 in the Upper Nan river basin (13,000 km2) was selected as a case study. The temporal and spatial distribution of the satellite rainfall products were statistically evaluated using volume bias, peak bias, root mean square error (RMSE), correlation coefficients (CCs), and the coefficient of determination (R2). The statistical performance of simulated flood runoff using the GSMaP NRT and 3B42RT rainfall products were also analyzed by the Nash–Sutcliffe efficiency index (NSE), CCs, and the RMSE. This study found that both satellite-based rainfall products demonstrated weak CCs and R2 values at most ground-based rain gauges with respect to daily rainfall intensity. Runoff simulation results from the IFAS model demonstrated better performance from the 3B42RT than the GSMaP NRT product (NSE: 0.79, CCs: 0.90, and RMSE: 18.03 mcm), despite the smaller pixel resolution of 3B42RT.
