台灣地區降雨時間空間分布本就極為不均，實際可使用之水資源卻不多，水資源的有效整合管理為永續利用的重要工作之一。河川伏流水(Hyporheic water)於伏流水層中流動，包含部分地表水，為地表地下水交換區域，具有較易取得與較佳水質的優點，伏流水可用水量開發與管理需合併地表水與地下水同時考慮，伏流水的蘊藏量以及如何取水可達到最佳效益等問題，一直是伏流水開發受關切與爭論的重點。本研究規劃為期三年期的研究時程，研究目標是以指標評估方法結合數值模式，聯合分析不同尺度河川伏流水豐枯時期地表地下水交換量與動態機制，發展台灣本島地區大尺度伏流水潛勢及量化評估方法，選擇示範河川輔以地表水及飽和/非飽和地下水模式分析，配合部分現地與實驗室試驗，量化評估豐枯水期地表地下水交換量與影響機制。伏流水潛勢評估將以指標評估方法做為篩選工具，以圖層空間資訊轉換為指標因子，配合克利金(Kriging)地質統計插值法，評分加權獲得伏流水開發潛勢分布。數值模式將以具有地表水與地下水水力動力機制耦合模擬模式為主，針對所篩選具潛能之河川沿線進行小尺度數值模式分析，以量化各河段不同因子條件下，地表地下水交換量。此外，以河川地表水需求水量限制條件下，推估伏流水適合取用水量。研究分析流程與成果預期可提供枯旱或洪泛時期，水資源調配管理的重要參考依據。 ;The nonuniform precipitation in Taiwan have made limited usage of water resources. Such difficulty leads to a challenging task in integrating available water resources for efficient and sustainable management. Hyporheic water flows under a river or stream and the area is the groundwater and surface water interaction zone. The development and management of hyporheic water for water resources requires interdisciplinary knowledge from hydrology and hydrogeology. Over the years, the storage and optimal use of hyporheic water have been the important issues for development of hyporheic water. The dynamics of water interactions in hyporheic zones are fundamental to quantify the storage and optimal use of hyporheic water resources. This three-year study aims to develop a procedure that couples index overlay and numerical models to assess the dynamics of hyporheic water flow for dry and wet seasons in river basins of Taiwan. The index overlay is for identification of large-scale sustainability of hyporheic water resources. A coupled surface water and saturated/unsaturated groundwater models is then used for selected sites to assess dynamics of surface water groundwater interactions in wet and dry seasons. The index overlay method uses selected weighting maps generated by Kriging geostatistical interpolation algorithm. Integrations of the maps than yield the distributions of sustainability for hyporheic water resources. Numerical simulations of surface water groundwater interactions require a physically based model that can reproduce the dynamics of surface water and groundwater interactions. The objectives of the river-scale numerical modeling are to quantify effects of hydrogeological properties on hyporheic water fluxes and dynamics along a river. Additionally, the strategies of hyporheic water management will be systematically analyzed. The procedures and results of this study are expected to provide key references for water resource management and allocations in drought and flood periods in Taiwan.
