トンレサップ湖流域におけるGPCPの特徴とその利用による水文・水理モデルの改善

抄録

  The Tonle Sap Lake in Cambodia is the largest fresh water lake in Southeast Asia. Hydrological and hydraulic models are powerful tools to understand water flow in the lake basin. However, due to poor measuring density of gauge-based precipitation in Cambodia, it is difficult to develop accurate models. In this study, Global Precipitation Climatology Project (GPCP) was used as satellite-based precipitation, and as a result of examining its characteristics, we found that GPCP tends to be larger values than gauge-based precipitation in the lake basin. Therefore, the hydrological and hydraulic model used GPCP after adjustment to improve model accuracy. The accuracy of the simulation of the hydrological and hydraulic model was evaluated by NSE. As a result, by using the adjusted GPCP for the hydrological and hydraulic model instead of gauge-based precipitation, the average NSE of the runoff discharge from seven watersheds, which is the simulation result of the hydrological model, was improved from 0.39 to 0.49, the NSE of the water level at Kg. Luong, which is the simulation result of the hydrological and hydraulic model, was improved from 0.93 to 0.97.