有效雨量之意義深廣且重要，人工灌溉僅為補充天然雨量的不足，常見有些無水利設施之看天田，仍然維持農作物之生長，可見有效雨量為灌溉的重要性。但近年來由於氣候變遷，降雨型態已不復以往，大多呈現降雨強度大且集中之現象，但整體降雨總量卻變異不大，此現象嚴重影響可利用的有效降雨量多寡，未來勢必造成直接影響整體灌溉策略，故本計畫目的在於探討不同降雨分佈型態對有效降雨量之影響程度，分析兩者之相關性。 Effective rainfall is a very significant component for crop requirement can supply demand of irrigation water in paddy field, special without irrigation facilities. Due to the climate change, the rainfall distribution pattern has been changed nearly decade. The rainfall trend appears intensity is strong and concentrated but not changes baldly in total precipitation. It is an acute problem for estimating how much effective rainfall can be used and affecting the strategies of irrigation in future. The purpose of this study is to analysis the relationship in rainfall distribution pattern and effective rainfall by the stochastic method. 研究期間：9606 ~ 9612
