本研究主要利用地下水位歷線與沉陷檢測資料，配合水井普查統計資料及土層材質與組織結構等相關資料，用以推求壓縮指標以及滲透係數 。研究範圍僅侷限於受壓飽和含水層，此層之土壤組織大多以砂和礫石為主。藉由構建地層下陷近似模式之解析解，進一步以受壓飽和含水層平面面積與地下水位變化率來取代抽水量難以估算的瓶頸，受壓飽和含水層平面面積之估算採用徐昇氏多邊形法。 推求壓縮指標以及滲透係數的範例，應用在屏東及雲嘉地區等16個觀測站。壓縮指標之計算結果顯示，「細砂」約略分佈在0.05~0.1 ；「粗砂」在0.03~0.05的範圍內；「礫石」則在0.03以下。滲透係數之計算結果，大致符合實驗室透水試驗各土層材質的試驗數據。 藉由分析比較壓縮指標及滲透係數的變異數 ，判斷此二係數的離散程度。並考慮地下水位歷線相關因子以及沉陷檢測資料對於壓縮指標及滲透係數之影響分析。 The objective of this study is to investigate the Compression index and the Permeability in groundwater. The analysis is based on the information of the groundwater hydrographs, detected data of land subsidence, groundwater well investigation and the related data of land soil. The current project is restricted to confined saturated aquifer and the composition of this layer is mostly sand and gravel. The estimation of compression index and permeability is based on the analytical solution of the approximate model of land subsidence. However, the surface area of confined saturated aquifer and the groundwater level gradient are used to solve the difficulty in estimating the pumping discharge,the surface area of confined saturated aquifer is estimated by the Thiessen polygons method. The algorithm of estimation of compression index and the permeability is applied to 16 sites in Pingtung, Yunlin and Chia-yi regions. The results of these sites show that the value of compression index is 0.05 ~ 0.1 for the fine sand, 0.03 ~ 0.05 for the coarse sand, and below 0.03 for the gravel. However, the computed value of permeability is almost the same with the experimental result of permeability test. The diversity of compression index and permeability can be determined by analyzing their variance. The impact analysis on compression index and permeability also take into consideration in this study, especially with the correlate factors of groundwater hydrographs and detected data of land subsidence.
