水層特性對於地下水污染物傳輸的影響與動力式參數值之推求

Abstract

本論文的主要目的，在利用模式探討水層特性對於地下水中污染物傳輸的影響，並推求一階動力式與Monod動力式所需要的參數值。在污染物傳輸的模式中，若能考慮到水層非均質、非等向及側向延散效應，則模擬結果應更能接近實際的分佈狀況。研究結果顯示，在非均質情況當中，污染物濃度分佈會因局部高透水性區域而造成偏移的現象，斗閘系統若沒考慮此非均質效應會無法有效收集與處理部分高濃度的污染團；在忽略側向延散效應的情形下，污染團的形狀會趨向扁平狀而在水流方向拉長。在非等向的情況時，因為Kx/Ky的比值大於1，使得污染團往橫向（y方向）偏移的程度減小，相反的，若Kx/Ky的比值小於1，偏移的程度則增大。在參數推求方面，本論文所建立的數值方法，可以求得較精確的Monod動力式參數值，若將這些參數值代入模式之中並考慮水層特性對濃度分佈的影響，應可以得到較佳的模擬結果。

The objectives of this thesis are to investigate the influences of hydrogrologic characteristics on the migration of contaminants in a confined aquifer, and to estimate the first-order and Monod kinetics parameters. Considering the effects of aquifer heterogeneity, anisotropy, and lateral dispersion, the results of contaminant transport modeling can be more representative for the real distribution. This study shows that under the influence of heterogeneity, the contaminant plume spreads and migrates unevenly. The funnel-and-gate system may fail to capture and treat contaminants if the effect of heterogeneity is not considered. In the absence of lateral dispersion, contaminants tend to migrate along the flow direction. In the cases of anisotropy, the hydraulic conductivity in the major (flow) direction is higher than that in the minor direction, causing the plume to travel more along the flow direction. Regarding parameter estimation, the numerical procedure established in this thesis can obtain more accurate parameter values. These determined parameters can be employed along with the aquifer characteristics to give better representation concerning the simulation of plume migration.