對氣候上，台灣中部地區年雨量約有1700mm~1800mm，理論上，應無缺水之虞。實際上，受限於降水集中在梅雨季、與颱風季的5-9 月，而10 月至次年的3 月為乾季，其中春雨（1-3 月）約佔本區全年總降水量的10%。就降水總量言，並不具絕對的重要性，但當梅雨及颱風雨不顯著時，春雨便顯得格外重要，如果前一年的颱風、梅雨雨量不足，且無春雨適時的補充，那麼形成乾旱的機率將大幅增加，不但嚴重影響一期稻作的秧期，連工業及民生用水都有缺乏之虞，此時，春雨對於水資源的調配將扮演舉足輕重的角色。因此，若能有效掌握春雨的預報，將對水資源的調度提供預警與對策擬定提供助力。本研究即針對上述需求進行研究，產出資料另支援本計畫之子計畫二、三。降雨採用克利金法對於量化趨勢可能性進行預測，並且透過區域面積遞減因子探討降雨空間分佈。在流量預測方面則利用GWLF，進行集水區豐水期與枯水期流量統計特性分析，並在氣候變遷情況下，擬定各種策略情境進行乾旱時期地區水資源模擬與相關策略研析，以期對於預警調配制度提供決策訊息之參考。 Annual precipitation is about 1700mm~1800mm in the middle of Taiwan. Water is not lack of this region in theory. But most of the precipitation concentrates in the plum season and typhoon season (May ~ September), the rainfall between Jan. and Mar. comprises about 10% of the annual rainfall amount. If plum rains and typhoon rains brought little rainfall, the amount for spring rains will be more than important than the past. Then the opportunity of a drought for the region gets more and more. The result will not only affect the planting of rice in the beginning of the year, but also cause lack of domestic water and industrial water. So, if we can predict the amount of spring rains in time, it will improve the allocation of water resources for decision makers. This study will be done for the above purposes. The output data will also support sub-plan II and III as one of their input source. The discussions and applications for our study can be spilt into : (1)The Kriging method will used to predict the rainfall amount and probability. The rainfall distribution will also discuss with local area gradually decrease factor. (2) The GWLF model will used to predict the stream flow. Analyze the statistics property of stream flow during both wet and dry season in study basin. (3)Assume scenario forecasts to simulate the local area water resource allocation policy during drought period. These results will be the reference for drought alert and water allocation policy. 研究期間：9908 ~ 10007
