COUPLING RLWE MODEL WITH DISTRBUTED HYDROLOGICAL MODEL FOR WATER BUDGET SIMULATION IN THE TONLE SAP LAKE

Tonle Sap Lake (TSL) plays an important role not only as a source of water resources, but also as a part of the Mekong River (MR) ecosystem. Therefore, assessment of current situation and possible future change of water budget in TSL is needed for water resources management and conservation of ecosystem of this region. In this study, we propose the methodology for simulating water budget of the TSL which can incorporate the interaction between the lake and surrounding hydrological system by coupling the River Lake Water Exchange (RLWE) model and the Yamanashi distributed Hydrological Model (YHyM). The performance of coupled model was verified by comparing simulated and observed daily water volume of TSL. Then the impact of precipitation change on TSL hydrological system was analyzed as a trial application using the coupled model. The results indicate a decrease of maximum water volume of TSL under future scenario which is mainly due to the reduction of water flow into the TSL from MR.