EVALUATION OF SATELLITE BASED PRECIPITATION AND ITS USAGE FOR FLOOD FORECAST AT BASIN SCALE

Abstract

This study aims to investigate the applicability of Satellite Based Precipitation (SBP) combined with rain gauges as input to a distributed hydrological model (DHM) for flood forecast. SBP was evaluated at different scales in upper Chao Phraya basin against available local gauge network in Thailand. The procedure includes the usage of Root Mean Square Error (RMSE) to assess the accuracy of SBP and Relative Error (RE) to evaluate the degree of estimation. Furthermore, RE values were utilized to obtain correction factors at each rain gauge per season. DHM was run during 2007-2010 to validate spatial and temporal accuracy of improved SBP. The river discharge simulations using corrected SBP could reduce the overestimation gaps when compared to observed discharge in target period. It was noticed that SBP can enhance precipitation’s pattern by using local gauge network. The obtained results show possibility to apply this procedure to other humid vegetated basins and also using other SBP dataset. We believe that this method can be useful not only for flooding risk assessment but also to support enhanced dam operation.