地层下陷重点集水区水源涵养力推估及最适地下水-中华水土保持学会.PDF

1 地層下陷重點集水區水源涵養力推估及最適地下水補注 區位篩選之研究 廖垂麟[1*] 張文彥 [1] 林昭遠[1] 摘 要 台灣雲林地區之主要產業為需水量高之養殖業及水田，在地面水缺乏與分配不均 下，地下水成為其主要之用水來源，然無節制地超量抽取地下水導致地層下陷嚴重，加上近年 極端降雨事件頻繁，地層下陷區亦具高潛勢淹水區位，如何利用環境指標推估地層下陷重點集 水區之水源涵養力及萃取適當的地下水補注區位，對地層下陷重點集水區極為重要。本研究以 雲林縣之虎尾溪集水區為樣區，利用土地利用圖及土壤圖套疊而得之曲線值(curve number) ，推 估集水區之水源涵養力空間分布，經分析開發前後 CN 值之差則可找出集水區易發生超滲逕 流之區位，另配合漥蓄區位萃取及斷層圖則可篩選適宜的地下水補注熱點，可營造具沉砂滯 洪、舒緩地層下陷、遊憩、生態景觀、灌溉及消防等多功能之截蓄保水設施。 關鍵詞 ：地層下陷、水源涵養、地下水補注、曲線值 Water storage capacity estimation and optimum groundwater recharge site screening for the significant subsidence watershed Chui-Lin Liao [1*] Wen-Yan Zhang [1] Chao-yuan Lin [1] ABSTRACT The main agricultural products of Yunlin County in Taiwan are the aquaculture and paddy field, which are higher water consumption. Due to water resources deficit and uneven allocation, the groundwater became the main source of the industries. However, the overuse of groundwater pumping without limitation results in serious land subsidence. In addition, recently the extreme rainfall events occurred frequently, areas of land subsidence were also vulnerable to high potential floods. How to estimate the capacity of water storage and extract the optimum sites of groundwater recharge for the significant subsidence watershed using environmental index is crucial. The Huwei Creek watershed in Yunlin County was selected as study area. The curve number (CN) derived from land use and soil map was applied to understand the spatial distribution of water storage. According to the changes of CN in a development watershed, the hotspots of excess runoff can be effectively deli