| 摘要: | 摘要 越南在快速城市化之後淡水的需求增加了，在Hadong區地下水更是一個非常重要的水資源。根據Hadong區政府的發展規劃，於2020年時這一區域的淡水需求量將達到約114,000 m3/day，因此需要對地下水資源進行有效的評估和管理。本研究利用三維有限差分模型VISUAL MODFLOW(VMOD)，輸入當地的地形，水文和氣候數據，建立該模型模擬河東區顆粒含水層的地下水流動，其中包含一個全新世的含水層(qh)和更新世含水層(qp)。利用31口井為期6年的地下水水位監測數據，以及利用現有技術將區域水力傳導係數和儲蓄係數的估計值納入模型，分別假設穩態和暫態條件律定此Hadong模型。模擬結果顯示，最佳抽水策略下此含水層所能提供的最大地下水供給量為124,830 m3/day，此供給量的來源由大至小分別來自Day River(35.97%)、研究區外(29.89%)、qh含水層(26.88%)、Nhue River(6.56%)和qp含水層(0.71%)。Hadong區政府預測：在2015年時淡水需求將達到91,320 m3/day，在2020年時達到114,552 m3/day，在2025年和2030年時分別達到128,298 m3/day和134,300 m3/day。模型預測地下水供給情況為：2015年和2020年為順差26,150 m3/day和10,278 m3/day；但在2025年和2030年時將呈現逆差3,468 m3/day和18,864 m3/day。 Abstract Groundwater is a very important water resource in Hadong area. The rapid urbanization of Hadong increases the need of fresh water. According to the development strategy of Hadong city government, the fresh water demand of this area will be around 114,000m3/day in 2020. Therefore, evaluation and management of groundwater are required, and are studied herein using a three-dimensional finite-difference model which is based on the VISUAL MODFLOW (VMOD) and utilizes the local topography, hydrogeology, and climate data. This model simulates the groundwater movement in the granular aquifers in Hadong area, which consist of a Holocene aquifer (qh) and a Pleistocene aquifer (qp). Six-year groundwater level data of 31 monitoring wells, the hydraulic conductivity distributions and storage coefficients estimated using available techniques are incorporated into the model. The calibration of the Hadong model are made assuming both steady-state and transient conditions. Based on the optimal pumping strategy modeled the maximum groundwater available from the qp aquifer is 124,830 m3/day, which is supplied by Day River (35.97%), the adjacent areas (29.89%), the qh aquifer (26.88%), Nhue River (6.56%), and the qp (0.71%). The predicted water demand will be 91,320m3/day in 2015, 114,552m3/day in 2020, 128,298m3/day in 2025 and 134,300m3/day in 2030. There will be groundwater surplus for 2015 by 26,150m3/day and for 2020 by 10,278m3/day. But there will be groundwater deficits in 2025 by 3,468m3/day and 2030 by 18,864m3/day. |
