花蓮溪沖積谷之地下水模擬與鳳林地區之地下水資源評估

Evaluation of Groundwater Resources in Feng-Lin Area by Modeling Hua-Lian Alluvial Valley

許少華(Shao-Hua Marko Hsu) ； 劉建榮(Chien-Jung Liu) ； 林伯聰(Bro-Thong Lin) ； 廖培明(Pei-Ming Liao)

《農業工程學報》 52卷3期 (2006/09) Pp. 64-75

https://doi.org/10.29974/JTAE.200609.0007

摘要

本文透過地下水流數值模式與現地試驗針對花運溪沖積谷之地文參數進行初步推估，並以地下水源僅做爲地表水源不足時之備用水源為原則，透過模式模擬枯水水文年鳳林地區之地下水水位經抽水後的回復能力，來分析鳳林地區的地下水永續可開發量。模式部分，以MODFLOW(PMWIN)配合200l年之水文資料修正模式參數，並以2002~2003年的現地地下水水位變化資料驗證模式參數之可信度。現地量測部分，則透過萬里溪上下游流量差異推估溪流底床之透水係數，作為模式參數給定與微調之參考。此外，並針對花蓮溪全域與各支流分區進行參數敏感度分析以及水平衡收支量(water budgets)的探討，發現含水層的水力傳導係數與溪流底床的透水係數爲此區域影響地下水水位的主要因素。各支流上游對花運溪沖積谷合水層之地下水側流補注僅對各支流分區有其重要性，對全域的平均地下水位則影響不顯著。

關鍵字

花蓮溪 ； 地下水水位 ； MODFLOW ； 敏感度分析 ； 水平衡收支量 ； 永續可開發量

並列摘要

Ground water parameters of Hua-Lian River basin were evaluated by comparing numerical results of MODPLOW (PMWIN) and field data. Different scenarios were performed by the calibrated model to determine the available quantity of groundwater resource for development in Feng-Lin area. The criterion for determining the available quantity of pumping is no significant impact on decreasing groundwater level in yearly basis. The discharge differences between the upstream and downstream of Wan-Li River were used to determine the river-bed conductance. Sensitivity analysis of major parameters and water budgets for the whole aquifer and all sub-region aquifers were performed, which shows that the conductance of river-bed and hydraulic conductivities of aquifer are the major parameters dominating the flow and level of groundwater. External inflow of ground water from tributary valley cannot be neglected in each sub-region aquifer, but is not important in the perspective of whole Hua-Lian River region.

並列關鍵字

Hua-Lian River ； Groundwater level ； MODFLOW ； Sensitivity analysis ； Water budget ； Safe yield