- 學位論文
兼顧環境流量之跨流域水資源運用－取法都江堰之引水概念
Incorporating Environmental Flows into Crossing-Basin Water Resource Operations - an Inspiration from the Dujiangyan
摘要
台灣過去常以建設水庫來解決水資源不足的問題，然而現今社會環境保護意識抬頭加上缺乏良好建庫位址，導致新建水庫困難，曾文越域引水工程即是因應美濃水庫無法興建而產生的替代方案；面對水資源開發不易的情形，發展良好的水資源管理策略就更形重要。本文以曾文越域引水為研究案例，探討不同時期的不同引水量對台灣南部民生與各種標的用水、以及荖濃溪流域與曾文溪流域的生態環境之影響，一旦我們必須以曾文越域引水來解決台灣南部水資源問題時，希望本文能提供一個較不損害生態環境利益，又能減少人類缺水狀況的可行方案，解決用水爭議。 本文以遺傳演算法模擬越域引水與水庫操作，同時併入引水比例與水庫蓄水量於遺傳演算法中搜尋最佳解，最佳化的目標包括：荖濃溪人類用水、荖濃溪生態環境用水、曾文水庫人類用水與曾文水庫生態環境用水；人類用水參考現行荖濃溪與曾文水庫各標的之計畫需水量，生態環境用水則以環境流態因子為評定標準，結合曾文水庫運用規線MT10規線評估人類缺水程度與環境流態因子，在設定權重下，整體滿意程度最高之解為最佳解，解集合中包括3個引水比例與36個水庫蓄水量共39個決策變數，其中引水比例的設計是來自都江堰的啟發。模式以民國64 ~ 87年荖濃溪與曾文水庫的流量資料進行操作，結果得到平均年引水量為21434萬立方公尺，比原計畫引水量少623萬立方公尺，並且對荖濃溪人類用水、荖濃溪生態環境用水與曾文水庫生態環境用水都有顯著改善，對曾文水庫人類用水貢獻度則較差。 文中也給予各個最佳化目標不同權重分配之組合，觀察權重更動後各個最佳化目標的變化，結果顯示權重的變化可以適當反應於結果中。本文的最佳化模式可以提供做為水資源管理者於決策時的參考。
並列摘要
This thesis studies Tseng-Wen Reservoir Transbasin Diversion by considering impacts on both water usage and environmental integrity simultaneously. The Tseng-Wen Reservoir Transbasin Diversion Plan proposes to divert water from the Launong River into Tseng Wen Reservoir. This study attempts to provide management strategies on water diverting rate and 10 days reservoir operation for an optimal solution of both water usage of southern Taiwan and environmental integrity of these two river basins by using genetic algorithm (GA). I developed water diverting rates at three flow conditions inspired from Dujiangyan, and 36 storage levels for reservoir to evaluate the optimal solution from GA simulations that minimizes water deficiency and maximizes environmental integrity. Historical flow data of Launong River and Tseng Wen Reservoir from 1975 to 1998 were compiled into six indices for the GA simulations with their associated weights. The GA simulation results show that the optimal water diversion is 0.05 of the low flow (flow less than 20 million cubic meter/10 days), adding 0.39 of the median flow (flow between 20 million and 100 million cubic meter/10 days), and adding 0.37 of the high flow (flow between 100 million and 200 million cubic meter/10 days). The water diversion is 0 because of the turbidity while the flow over 200 million cubic meter/10 days. Under this optimal operation, the results of the water deficiency at Launong River, and the environmental integrity at Launong River and Tseng-Wen Reservoir are better than the original plan.