EVALUATION OF BIAS CORRECTION METHODS FOR FUTURE RIVER DISCHARGE PROJECTION

Abstract

 The objective of this study is to apply the differential split-sample test (DSST) to evaluate appropriate bias correction methods for future river discharge projection using the present climate GCMs data for dry and wet years and observed data for validation. A distributed flow routing model (1K-FRM) is used to obtain the dry and wet years in the present climate experiment by inputting the runoff generation data output from MRI-AGCM3.2S, a 20 km spatial resolution general circulation model (GCMs) developed by the Meteorological Research Institute, Japan. The Nan River Basin in Thailand is selected and several kinds of bias corrected inflow to Sirikit reservoir located at midstream of Nan River Basin are evaluated for a time period of 1979-2003. An effective bias correction method is proposed with suitable statistical performance considering a non-stationary condition for applying the bias correction methods to future discharge estimation.