River discharge projection in Indochina Peninsula under a changing climate using the MRI-AGCM3.2S dataset

Abstract

River discharge in Indochina Peninsula region was projected using a distributed flow routing model (1K-FRM) with kinematic wave flow approximation for three climate experiments: the present climate (1979-2008), the near future climate (2015 - 2044), and the future climate (2075-2104). Topographic data used for the flow routing model is 5-minute spatial resolution data which was processed from scale-free global stream-flow network dataset. The flow routing model 1K-FRM was fed with general circulation model (GCM) generated runoff data for three climate experiments. The GCM dataset used was the latest 20km spatial resolution general circulation model (MRI-AGCM3.2S), which was developed by Meteorological Research Institute, Japan Meteorology Agency. The changes of flow in Indochina Peninsula region under climate change were analyzed by comparing simulated river discharge for the present climate, the near future climate, and the future climate experiment. Analysis results show clearly changes of annual mean discharge, mean of annual maximum discharge and mean of annual minimum discharge with the degree of changes different according to location. The changes, which were detected in the near future climate conditions, become clearer in the future climate conditions. In some locations, the increase of flood and drought risk was found.