臺灣博碩士論文加值系統

本研究之主要目的，乃針對特定污染源區域之最佳監測井網設計下，決定抽水井位置來提高監測井網偵測污染物之機率。其研究步驟乃是先以一般監測井網最佳設計之方法來確定監測井網之最佳位置，並利用本研究中計算各個格點單一污染物偵測機率之方法，求出每一格點之污染物偵測機率，再由已決定之最佳井網中選取偵測機率較高之數個井點來施加抽水，以達到引導水流及改變污染物傳輸方向之目的；而最佳井網中抽水點位置與個數之決定，則必須滿足安全洩降之限制以及達到最大偵測機率或最少設置總成本之目標。經由在監測井上加以抽水之方式，本研究期望能在有限經費的限制之下減少監測井網之設井數目，並提高或至少維持對污染物之偵測機率。
本研究所建立研究方法之步驟包括：（1）假設研究區域之水力傳導係數場呈對數常態分佈來產生大量組數之隨機水力傳導係數分佈；（2）針對不同之可能污染滲漏源以及隨機產生之水力傳導係數場，利用水流模式MODFLOW及污染物傳輸模式MT3D來模擬污染物之濃度分佈情況；（3）利用簡單之統計機率觀念來計算每一格點對污染物之偵測機率，以作為設置監測井網及選定抽水點之依據；（4）比較抽水井之設置與否對監測井網偵測機率之影響。
最後，本研究利用一個三維之假設性場址來說明本研究方法應用之情況，經分析應用結果後可獲致以下之結論：（1）於偵測機率較高之候選監測井點施以抽水，可改變水流之方向並引導污染物之傳輸途徑趨於流向監測井處，因此可提高監測井對污染物之偵測機率；（2）欲達到提高偵測機率目的而進行之抽水，將會導致地下水位之洩降增加，恐有地層下陷之虞，故應考慮在不致造成地層下陷的安全洩降內採用適當之抽水率；（3）本研究另於抽水井點下游處加設一補注井，以探討其設置對監測井網之影響，結果發現補注井之設置不僅可使抽水處之洩降微幅減小，更因下游邊界的地下水位提高而使得污染物流向下游邊界之趨勢減緩，進而增加了污染物流向抽水井點處之機會，而使得抽水監測井處之偵測機率提高。

The main purpose of this research is to develop a methodology for designing an optimal monitoring network of a site-specific polluted location. The methodology introduces the utilization of pumping- monitoring wells to increase the probability of detecting contaminants. The first step is to decide the optimal locations of monitoring wells by general methods for monitoring wells design, and compute the detecting probability of each cell by the method developed in the study. The monitoring wells of higher detecting probability are then chosen for pumping in order to achieve the purpose of guiding groundwater flow and change the transporting direction of contaminants. To decide the locations and numbers of pumping wells, constraints of allowable drawdowns at given locations must be satisfied. The objective function is to maximize the detecting probability or minimize the total cost.
The steps of the developed methodology include: (1) assuming the hydraulic conductivity field of the research region be lognormal and generating lots of the random hydraulic conductivity fields; (2) according to the different sources of pollutants and the random hydraulic conductivity fields, generating lots of distributions of contaminants by MODFLOW and MT3D models; (3) calculating the detecting probability of each cell by using simple concept of statistics in order to decide the locations of monitoring and pumping wells; and (4) investigating the influence of setting up pumping wells.
Finally, a hypothetical problem of three dimensions is used to illustrate the developed methodology. The conclusions are: (1) The direction of groundwater flow can be changed and contaminants can be guided to monitoring wells by pumping at monitoring wells of higher detecting probability and, therefore, the detecting probability of monitoring wells can be increased; (2) Pumping will lead to a higher drawdown, so we should choose appropriate pumping rates in order to satisfy the constraints of allowable drawdowns; and (3) This research also sets recharge wells in the downstream beneath the pumping wells to investigate the influence to the monitoring network and we can find that the installation of recharge wells doesn’t only decrease the drawdown at pumping point, but also increase the detecting probability.

第一章導論
1-1 前言………………………………………………………1
1-2 文獻回顧………………………………………………2
1-3 研究目的、方法與步驟………………………………3
第二章模式介紹
2-1 MODFLOW 模式…………………………………………5
2-1-1 地下水水流方程式……………………………………5
2-1-2 初始條件………………………………………………6
2-1-3 邊界條件………………………………………………6
2-2 MT3D模式………………………………………………7
2-2-1 控制方程式……………………………………………7
2-2-2 初始條件………………………………………………8
2-2-3 邊界條件………………………………………………8
第三章抽水監測井之設計
3-1 最佳監測井網之決定…………………………………11
3-2 抽水井點之選擇………………………………………13
第四章假設性範例
4-1 各格點之單一偵測機率值……………………………15
4-2 抽水對單一監測井點偵測機率之影響………………16
4-3 抽水對多口監測井組偵測機率之影響………………17
4-4 結果與討論……………………………………………18
第五章結論與建議……………………………………
5-1 結論……………………………………………………20
5-2 建議……………………………………………………21

陳冠志，「異質性土壤中二相流及溶質傳輸行為之研究」，國立成功大學資源工程學研究所碩士論文，2001。
Everett, L. G., Groundwater Monitoring, General Electric Com- pany, Shenectady, New York, 1980.
Massmann, J., and R. A. Freeze, Groundwater contamination from waste management sites: The interaction between risk-based engi- neering design and regulatory policy, 1, Methodology, Water Resour. Res., 23(2), 351-367, 1987a.
Massmann, J., and R. A. Freeze, Groundwater contamination from waste management sites: The interaction between risk-based engineering design and regulatory policy, 2, Results, Water Resour. Res., 23(2), 368-380, 1987b.
McDonald, M. G., and A. W. Harbaugh, A Modular Three- Dimensional Finite-Difference Ground-Water Flow Model, USGS, United States Government Pring Office, Washington, 1988.
Meyer, P. D., A. J. Valocchi, and J. W. Eheart, Monitoring network design to provide initial detection of groundwater contamination Water Resour. Res., 30(9), 2647-2659, 1994.
Storck, P., A Three-Dimensional Method for The Design of Ground-water Monitoring Well Networks, M.Sc. thesis, Univ. of Ill., Urbana, 1997.
Zheng C., and P. P. Wang, A Modular Three-Dimensional Multi- species Transport Model, 2000.