圖書典藏及影音數位平台

台灣地區自民國84年推動地層下陷防治執行方案以來，已累積多年的地下水位及地層下陷監測資料，且已建置多口分層監測井，提供每月所累積之地層下陷壓密與地下水位變化資料。近年來部份測站的地下水位雖未呈現明顯下降趨勢之週期性震盪變化，但地層下陷量卻仍緩慢增加。有鑑於地下水位變化與地層下陷量呈現複雜交互關係，本計畫將探討地下水位與地層下陷交互關係之文獻蒐集與探討，並建立載重及抽水作用下地層下陷數值模式；以濁水溪沖積扇為例根據地層下陷潛勢模擬結果，配合地下水位變化趨勢，進行地層下陷警示之評估探討與流程建立，以供地下水管理之參考。

This study first collected and analyzed the groundwater level data and land subsidence data in the Zhuoshui River alluvial fan, and then examined the correlation of layered groundwater levels in vertical and horizontal directions. The correlative analysis of layered groundwater levels could be used to check the reliability of hydrogeologic setting in vertical direction, and demonstrate the distribution of different soils in horizontal direction. Based on calibrated and verified soil parameters, three land subsidence probability models were used to conduct different time-scale assessments of land subsidence potential including long-time, real-time, and annual estimations. The long-time land subsidence assessment is suitable to engineering policy planning but can be substantially influenced by the uncertainty of pumping rate. In addition, for the real-time land subsidence probability model, land subsidence potential could be underestimated and real-time groundwater level could not be obtained. Therefore, the annual-rolling land subsidence probability model was appropriate for warning analysis of land subsidence potential. The annual-rolling land subsidence probability model was used to assess the land subsidence potential the Zhuoshui River alluvial fan in 2016 and identify warning area of land subsidence. If the pumping well is located in the land subsidence warning area, the groundwater resource management requires to be conducted by integrating groundwater level variation with land subsidence potential. However, the groundwater level variation is only considered to manage groundwater resource while the pumping well is not located in the land subsidence warning area. In addition, this study also developed and evaluated a land subsidence model simultaneously considering groundwater pumping and surface loading involving static loading of engineering structure and dynamic loading of traffic.