地下水最佳化抽取模式及管理方式之探討

Optimal Allocation and Regulation of Groundwater Pumping

陳漢穎(Han-Ying Chen)

指導教授 ： 游景雲

國立臺灣大學/工學院/土木工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101426

摘要

地下水資源的使用可以增進社會福祉，惟若管理不當可能對環境造成難以挽回的傷害。因此，數十年來科學家對於地下水管理研究不少，而理想的管理應包含三個步驟：適當抽取量的評估、水權的分配以及相關規範之擬訂。現實上，水文地質條件變化甚大，再加上抽水造成之洩降錐產生外部性，使得農民抽水時互相影響且可能負擔不同成本。本研究以雲林縣虎尾鎮為例，目標為最小化模擬區域之總成本或成本變異數，從而增進社會福利或公平性。透過對地下水系統之分析，能夠大致判斷對於個人或社會來說，各水井之抽水行為應如何調整才能達到目的，而本研究提出之GA-MODFLOW偶合模式可以達成上述目標並作為政府規劃最佳化抽水模式之參考。然而，農民未必願意遵守，故在規劃抽水模式後仍需考慮可能之不合作行為對於社會及個人之影響並規範。理論上，在灌溉水量及產量固定的條件下，農民只有在違規行為能降低成本時，才能獲取更大利潤，因此政府可以根據違規者成本變小的程度來加強監控，並根據目標函數變壞的程度制定相應的懲處措施。由於實際違規行為可能十分複雜難以完整涵蓋，本研究中僅個別考慮某一人在某一天違規的情況，而與成本變化相似的是，根據水文地質條件、水井位置及抽水模式的不同，每位農民的違規行為對社會或個人的影響不盡相同。

關鍵字

地下水管理 ； 洩降錐 ； 最佳化 ； 抽水模式 ； 抽水管理 ； 基因演算法 ； MODFLOW

並列摘要

Groundwater management has been discussed for past decades due to benefits and potential harm on the environment. A sound management should consist of three parts: determination of appropriate exploitation, allocation of water rights, and regulations. According to hydrogeology and the cone of depression, it may cost farmers diversely to pump in reality. For this study, Huwei Township, Yunlin County is selected and the goal is to gain social welfare or improve fairness by minimizing the total or variance of pumping cost in the simulated region. Through the analysis of the groundwater system, how pumping behaviors should be adjusted could be roughly determined. A GA-MODFLOW coupled model proposed in this research is able to find an optimal pumping schedule to achieve the goal. However, non-cooperation occurs and the im-pacts of violations should be deliberated. As the total irrigation amount and production are assumed constant, farmers earn interest only when their costs are reduced after viola-tions. The government could focus on these “hot spots” based on the decrease in the vi-olator’s cost and punish the violations based on the increase in total or variance. Similar to diverse costs, farmers’ violations cause different influences on the society or individual according to varied hydrogeological conditions, locations and pumping schedules.

並列關鍵字

groundwater management ； cone of depression ； optimization ； pumping schedule ； pumping regulation ； Genetic Algorithm ； MODFLOW

參考文獻

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