應用季節性預報資訊於乾旱時期鳳山溪流域地下水變化探討

In order to effectively manage groundwater resources during the dry periods, this study proposed a methodology to incorporate seasonal forecasting with hydrological models as inputs to simulate the seasonal variation of groundwater. The research area comprised mainly of Fengshan Creek basin (250 km²) in northern Taiwan. In addition, the drought events in recent years were our major focus. Hence the seasonal outlook, issued by Central Weather Bureau of Taiwan (CWB), was incorporated with weather generator (WGEN) and used as inputs for WASH123D to simulate the groundwater level. The results showed that, the accuracy of rainfall forecasting directly affects that of seasonal variation of groundwater level. The variation trends of groundwater level could be predicted as the seasonal outlook is in the interval of gauge observations. In short, this study indicated that, the proposed approach provided valuable information for groundwater resource management.