面對氣候變遷的衝擊、極端氣候的因素，除乾旱、暴雨發生的可能性變化，氣候降雨型態與過去大不相同。由於氣候變遷的衝擊，各標的用水衝擊增大，本研究目的在評估受氣候變化影響與不同的降雨型態下的影響，對農業灌溉及迴歸水利用可能發生之情況。利用水文序率方法，加入影響降雨型態之條件機率，進而模擬未來可能發生降雨分佈型式，在目前研究區域內的灌溉水源供需情況下，延續不同降雨降度及分佈情形對整體灌區的有效降雨量之影響情形，若以此探討可能產出之農業迴歸用水量，對於農業生產影響及水源調配之可行性，以供農田及水利相關單位於耕作或乾旱發生期間，用水調配之參考。重要工作項目如下： (1)資料收集與文獻回顧； (2)石門水庫灌區降雨量與作物需水量之關係分析； (3)考量石門水庫灌區除了水庫供水系統外，納入其他相關農田灌溉系統支援； (4)水文序率模擬：導入降雨影響參數，模擬氣候變遷之雨量變化。 (5)灌溉期程中農業迴歸水量及利用的探討。 (6)報告編撰。在現有研究區域內的灌溉水源供需情況下，探討不同降雨降度及分佈情形對整體灌區的有效降雨量之影響情形，農業期作種植期程產生之迴歸用水對於日後農業灌溉或缺水調度的影響，以供農田水利相關單位未來面對有關應變處理時之資料支援、農耕對策能進行更準確之評估。 According to the impact of climate change and extreme weather condition, the change possibility of drought or rainstorm has occurred. No matter in dry or in wet season, the top mission of hydraulic office is control enough water quantity to use anytime. Rain pattern and form are quite different than usual. The purpose of this study is try to discuss the influence of irrigation return flow under climate change and different rainfall pattern. One of the main water sources of agriculture irrigation is channel, the other is rainfall. The main character of rainfall can separate into quantity, strength and frequency. There are very important for space-time distribution influence. The method of hydrology statistics and rainfall variation condition were used to estimate the possible future rainfall distribution pattern. Under the condition of irrigation demand in study area, different rainfall pattern was corresponded to different effective rainfall. The possible volume of agriculture return flow will be an important information of water resource allocation for the policy of grovnment office. The main study procedures are as below: 1.Data collection and literature review. 2.Analysis the relationship of rainfall and corps demand in the Shihman reservoir irrigation area. 3.Establish the irrigation water resource supply and demand system. 4.Hydrology estimate. Import the rainfall variation coefficients and estimate the difference of rainfall. 5.Discuss the using and volume of irrigation return flow in corps irrigation period. 6.Report writing. 研究期間：9805~ 9812
