由於台灣近年每逢颱風來襲所夾帶之豪大雨，屢屢造成供水系統之原水濁度飆高，遠超出淨水場可處理能力，因此建立穩定且永續之供水備援系統實刻不容緩。淺層含水層因同時具有降雨、河川與地下水側向補注等來源，以河畔取水形式可於豐水期取得乾淨水源，枯水期可截留部分伏流水，且經由土層之入滲過濾，可降低河川水污染物及細菌濃度，為可行之開發或備援水源方案。為評估地下水流數值模式MODFLOW 應用於評估現場各項水文變化量之適用性，本研究利用解析模式驗證數值模式之適用性，分別以Grigoryev(1957)、Hantush(1965)、Wilson(1993) 與Hunt(1999)等四種解析模式，評估MODFLOW 應用於模擬抽水井河畔取水之適用性，利用 Joshi(1988)驗證水平集水管模式。本研究提出於林邊溪與曾文溪河畔，設置寬口井進行水源開發，水文地質參數之敏感性分析有助於現場模式驗證，抽水井形式之敏感性分析則可應用於出水方案設計。藉由現場試驗推估水文地質參數，利用地下水流數值軟體MODFLOW 建構現場數值模型，模擬取用目標出水量時，河畔取水對地下水位之影響。 Taiwan is hit by typhoons along with torrential rains in recent years, the raw water for the water system would usually rise to a level of high turbidity, far beyond the capacity of the water purification station. Therefore, it is of great urgency to establish a steady and sustainable water supply backup system. The shallow aquifer is sourced by rains, rivers, and groundwater side recharge. By pumping near the riverbank, it is able to obtain clean water in wetting season and also intercept part of the groundwater during the drying season. Furthermore, the seepage on the soil stratum as well as the seepage is able to decrease the contamination and bacterial concentration of the water from rivers. Thus, it can be considered as a developable backup water supply program. To evaluate the applicability of MODFLOW being used for all hydrological variations on the site, the study makes use of analytical models to verify its applicability. Assessment the effect of the pumping activity to the river seepage, using four analytical models that were developed by Grigoryev (1957), Hantush (1965), Wilson (1993), and Hunt (1999) to evaluate the applicability of MODFLOW being used for simulating pumping near riverbank. Furthermore, utilizes the analytical mode of Joshi (1988) to verify the horizontal collection well mode. The study proposes large wells to be built for water source development in the Lin-pin River and Zeng-wun River. To undergo sensitivity analysis for hydrological geology parameters that can help to verify the mode of the site, the corollary process of sensitivity analysis for the pumping well form can be applied in the water supplying program design. These sites are used to estimate the data on hydrogeology conditions. The study uses the groundwater software MODFLOW to create the site numerical model, which will indicate the influence of groundwater levels from water development.
