圖書典藏及影音數位平台

彰化與雲林位於濁水溪沖積扇，為台灣主要地層下陷區，其中彰化地區在99年度最大下陷速率約6.4公分/年，持續下陷面積約138.9平方公里，且下陷面積持續增加。為減緩彰化地區的地層下陷問題，尋找替代地下水的水源為重要項目之一。因此「烏溪水資源開發分期推動計畫」於民國94年開始推動，於民國96、97年進行烏溪鳥嘴潭攔河堰初步規劃，進行場址的地質調查與區域地下水文調查，民國98～100年進行工程可行性規劃、環境影響評估、民意調查等工作。烏溪鳥嘴潭人工湖預定工址位於草屯鎮北勢里(如圖1)，此人工湖主要為了滿足草屯及彰化地區民國120年之公共供水所需，冀望藉由烏溪地面水與彰化現有地下水源聯合運用，取代彰化地區部份地下水資源之取用，以使該地區之地下水資源能獲得休養，並減緩地下水超抽引起之地層下陷問題。 鳥嘴潭人工湖之設置截取了烏溪上游的水源，其對地下水資源的補注將可能造成負面之影響，也可能引起如集集攔河堰造成濁水溪下游之農業灌溉地表水減少，與河床沉積物減少引起之橋墩外露等問題。考量鳥嘴潭人工湖之設計與供取水情形對彰化地區地下水資源與地層下陷問題的影響尚未有較完整的評估工作，因此本計畫擬針對鳥嘴潭人工湖的建立，對彰化地區的地下水資源與地層下陷問題做進一步的分析與評估，辦理二年期計畫。

In order to mitigate the subsidence problem in the Changhua County, seeking new water resources to replace the groundwater use is the most important issue. Therefore, the development of the Niaozueitan Artificial Lake in Wu River is proposed. The artificial lake is planed to supply the public water use in the Caotun Township and Changhua County in 2021. The increase surface water supply can decrease the groundwater pumping of Taiwan Water Corporation and increase the groundwater level; thus, mitigate the land subsidence problem. The influences of the development of the Niaozueitan Artificial Lake on groundwater resources and land subsidence problem are not yet estimated. Therefore, this project focuses on dealing with these works and provides a two-year project to evaluate the influences and draws a strategy for preventing the subsidence problems in the Changhua County. The works in this project includes two years. The first year is focused on collecting the basic data and information, evaluating the influences on groundwater resources and on land subsidence in the Changhua County after the development of the Niaozueitan Artificial Lake. The basic maps in the Changhua County will be prepared for the numerical modeling of both groundwater flow and subsidence models. The scenarios for the decrease or stop pumping of groundwater of the Taiwan Water Corporation will be drawn up and input to the models to evaluate the influences on groundwater resources and land subsidence. The second year is focused on evaluating the climate change effect. Climate change can increase the temperature and change the quantity and intensity of rainfall, thus, affects the groundwater resources and further influences the land subsidence. Therefore, the climate change effect will be considered in the models to evaluate the influences after the development of the Niaozueitan Artificial Lake. In the end, the drift of strategies for the management of groundwater and land resources will be provided to prevent the subsidence problem in the Changhua County.