頁籤選單縮合
題 名 | 以不同思維探討旗山溪土砂災害之清疏問題=A Different Perspective on the Dredging of the Chishan River after Debris Disaster |
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作 者 | 周湘儀; 吳孟修; | 書刊名 | 水土保持學報 |
卷 期 | 47:1 2015.03[民104.03] |
頁 次 | 頁1247-1257 |
分類號 | 434.273 |
關鍵詞 | 旗山溪; 伏流水; 清疏; Chishan River; Interflow; River dredging; |
語 文 | 中文(Chinese) |
中文摘要 | 2009年侵襲台灣之莫拉克颱風,其長延時及高強度之暴雨造成旗山溪集水區上游多處崩坍,大量土砂進入河道,使政府須編列經費辦理野溪清疏之工作,惟清疏後之河道易因颱風豪雨事件而再度淤積,故土砂災害後野溪清疏之議題仍有討論空間。為此,本研究篩選颱風前、後降雨量相近之暴雨事件,並比較其水文歷線變化,結果顯示淤積土砂可增加地下水貯存並遲滯洪峰。由實地調查發現,未清疏河段因淤積土砂導致流量歷線延長,可增加入滲補助下游流量之現象。上述結果反映未清疏河段可有效涵養水源,如同非拘限含水層,扮演著水資源涵養之重要角色,此為因應氣候變遷下大自然為吾人所做之最佳調適策略,故土砂災害後河道內淤積土砂清疏之必要性有待重新思考。 |
英文摘要 | Typhoon Morakot with long duration and high intensity rainfall caused several landslides at the upstream watershed of Chishan River in Taiwan. The central and local governments have spent lots of budgets for dredging due to debris deposited on the river channel. However, the dredged sites are easily refilled by the recurrent debris following the next heavy rainfall events. The issue which involved river dredging for the debris disaster areas is still disputable. The storm events with similar rainfall amount occurred on the pre- and post-Typhoon Morakot were selected in this study. Rainfall hyetograph and runoff hydrograph of Chishan River from both events were compared. It shows that the debris in the river could enhance subsurface storage and result in a decrease discharge. In the dry season, field investigations show that water resources stored in the creeks without dredging could become seepage to recharge the downstream discharge. The results showed that the creeks without dredging could be served as an unconfined aquifer layer and playing important roles in water storage. For the viewpoint of water resource cultivation, the phenomenon of original creeks deposited by the debris might be a way of adaptation strategy made by the nature in response to climate change. Hence, the necessity of dredging in the creek channel after debris disaster should be reconsidered in a specific watershed. |
本系統中英文摘要資訊取自各篇刊載內容。