圖書典藏及影音數位平台

九二一震後大甲溪流域環境驟變，目前流域尚處於災後調整期，復建工作估計約需數十年才能恢復震前景觀，而氣候變遷與極端降雨加重水土災害外，又衍生水土資源管理難題，亟需以流域角度進行風險評估，並提出適宜之對策。為加強大甲溪流域之維護管理，提高水利建造物之安全，本計畫提出洪災風險分析架構，並針對流域進行全面性風險評估，包含地質與地震檢討、安全監測資料分析、防洪構造物結構安全評估、警戒與警報系統評估、溢潰堤演算、以及災損評估與緊急應變計畫等，此外本計畫亦納入水利建造物安全性檢測成果，最後針對「水利建造物檢查及安全評估辦法」相關規定進行檢討並提供建議改善項目，以建立完善之風險評估、安全檢查與安全評估制度。以下簡要摘錄本計畫工作成果。

The natural environment of Dajia River Basin have changed drastically due to the Chi-Chi earthquake in 1999. The environment should be returned to the condition before the earthquake after several tens years restoration projects. However, the global climate change and extreme rainfall exacerbate the debris and flood disasters which increase the diffculty of water resources management. Thus, a flood risk assessment based on basin scale is required to establish the optimum regulation strategy. To enhance the management of Dajia River Basin and the safety of flood defence structures, this project presents the framework of flood risk analysis and applies it on the whole catchment. The flood risk assessment includes (1) assessment of geology and earthquake influences; (2) analysis of monitoring data; (3) investigation of the safety of flood defence structures; (4) evaluation of early-warning system; (5) simulation of dike failure; and (6) review of emergency plan. Moreover, the outcome of the report of “The Safety Analysis and Evaluation of Dikes on Dajia River” will be incorporated into this project. Based on the above works, the regulations for safety inspection of flood defence structures will be reviewd to establish a consummate system for risk assessment, safety inspection and evaluation