應用決策理論中期望值準則(expected value criterion)處理水文高度不確定性下之調適策略決策問題，其藉由整合機率概念進行水源枯旱風險之計算，提供決策者合理且客觀之量化風險值，以作為後續水資源政策推動參考。以臺南水資源系統為例，將水源枯旱風險定義為缺水率或經濟影響之期望值，而調適策略效益評估結果指出：臺南高雄水源聯合運用(S2)與山上淨水場改善工程(S8)於減緩缺水上有較高之效益，而效益次高之策略則為永康安平再生水(S3)與白河水庫後續更新改善(S4)，以上調適策略若能順利推動，每個策略皆可減緩公共用水缺水率約2.1%至3.0%。

The expected value criterion from decision theory is applied to evaluate the adaptation strategies under hydrological uncertainty. Drought risk of the water source can be calculated from the concept of integration probability, providing decision-makers reasonable and objective quantitative risk assessment for subsequent policy decision making. The water resources system in Tainan is selected as the area of study. Drought risk of water source is defined as a water shortage ratio or expected economic impact. The benefit of adaptation strategies indicates Water Resources Conjunctive Use in Tainan/Kaohsiung (S2) and improvement of water Treatment Plants on Mountains (S8) have a higher benefit in alleviating lack of water, while the strategies with the second higher benefit are Reclaimed Water in Yongkang/Anping(S3) and Rehabilitation of Baihe Reservoir(S4). If the strategies above can be promoted successfully, each strategy will reduce the public water shortage rate by about 2.1% to 3.0%.