氣候變遷對大漢溪及新店溪流域防洪系統潛在衝擊影響之研究

A Study of the Potential Impact of Climate Change on the Flood Protect System for Da-Han Stream and Shih-Dan Stream

謝龍生(Lung-Sheng Hsieh) ； 柳文成(Wen-Cheng Liu) ； 童慶斌(Ching-Pin Tung)

《農業工程學報》 50卷3期 (2004/09) Pp. 32-47

https://doi.org/10.29974/JTAE.200409.0003

摘要

本研究之主要目的係針對研究流域防洪系統，評估未來短中長期各種可能氣候變遷情境條件下，河川洪峰流量對於集水區防洪系統之衝擊影響。於研究過程中，選取淡水河大漢溪及新店溪流域爲區域，首先利用現況調查及觀測資料蒐集，進行流域降雨分析及建立適用於集水區之水文模式，並進一步整合氣候變遷分析之成果，以探討未來各種可能氣候變遷之預設情境對於研究區域重要控制點尖峰設計流量之變化趨勢，進一步與過去水利主管單位所公告之河川尖峰設計流量及現有堤防防洪能力進行比較，以評估其衝擊影響。研究結果顯示，不論是以平衡試驗氣候變遷預設情境，或是在SRES氣候變遷預設情境下，其河川流域最大保護標準洪峰流量將有增加之趨勢；針對因氣候變遷所引致河川洪水增加量對流域現有防洪系統之衝擊影響，本研究進一步從現有堤防防洪能力、法規設計標準及災害管理系統等方面進行探討，提出具體之潛在衝擊影響，惟氣候變遷影響評估具有相當高之不確定性，因此在應用上，建議採用多個GCM氣候變遷模式預測情境之趨勢分析，而預測變化量之參考價值相對較低，不宜直接應用於決策。此外，本研究已建立適用於氣候變遷對集水區防洪系統衝擊影響之評估方法，未來將可推廣至其他流域，以做爲各種氣候變遷趨勢對全台防洪系統衝擊影響之整體性評估。

關鍵字

氣候變遷 ； 防洪系統 ； 河川洪峰流量 ； 衝擊影響 ； 不確定性

並列摘要

The main purpose of this study is to analyze and to assess the impact on flood protection system of watershed by flood discharges under various scenarios of short, mid, and long-term climate changes. The Da-Ham Creek and Shih-Dan Creek were chosen as the study areas. Observed data in the study area such as precipitation and discharge data were collected to analyze rainfall frequency and to setup the suitable hydrology model. The results of climate change scenarios were analyzed to investigate the possible changes in flood discharges at important control points in the river systems using the hydrology model. The simulated discharges were compared with the design discharges of the Water Conservancy Department to evaluate the defense ability of the present flood control system and the potential impact on watershed. The results showed that the flood discharge consistently exhibits a rising trend under both the balance test and SRES simulation scenarios for short, mid, and long-term climate changes. For the increasing of flood situation, this study evaluated the potential impact from three aspects including present ability for flood protection, laws and regulations for design standard, and hazard management system. Because of the high uncertainty in impact assessment of climate change, we suggested that several GCM analyses be adopted in the application. The methodology to assess the impact on flood protection system caused by climate changes had been established and should be applicable to other river basins. Therefore the integrated impacts of climate changes on the flood protection system in Taiwan can be performed.

並列關鍵字

Climate change ； Flood protection system ； Flood discharge ； Hydrology model ； Simulation