目前臺灣地區之橋梁因颱風及豪雨而受災，其主要原因在於土石流與洪水沖刷造成之破壞。因此，本研究首先建立橋梁受土石流與洪水沖刷潛勢評估之流程，以利未來颱風來臨時，預先評估橋梁受災之可能性。此外，本研究以累積雨量與最大降雨強度發生時之雨量，藉由雨量推估方法中之克力金法(Kriging)，求出橋梁所在位置之雨量資訊，並結合土石流潛勢指標與洪水沖刷潛勢指標，分析出橋梁因雨量而受損之臨界線後，再以兩個歷史颱風之降雨量驗證此臨界線之正確性。 本研究並藉由評估橋梁受土石流與洪水沖刷潛勢所需之資料，擬定災損橋梁資料庫功能，並藉由專家訪談確立系統需求，最後進行各功能模組之驗證。此資料庫亦可提供橋梁災損相關資訊記錄之功能，如: 水位、雨量、堰塞湖資訊、災後照片等，並以地理資訊系統展示，使災損橋梁災情資訊與周遭環境條件能得以完整保存。 本研究之成果包含(1)建立橋梁受土石流與洪流沖刷潛勢之評估流程，(2)建構橋梁受土石流破壞與洪流沖刷破壞之臨界雨量線，以及(3)建置災損橋梁資料庫。本研究之成果對後續有關橋梁方面減災、防災之工作，應可達先期預警之成效。 Impacts of debris flows and floods scouring are the two major factors that cause bridge damages in Taiwan. For precaution purposes, this research established two evaluation processes for assessing possible hazards of bridges caused by these two factors. In addition, this research incorporated the Kriging method to estimate the amount of rainfalls at the bridge site. Along with the indices generated by the evaluation processes, two critical boundary lines of rainfalls were drawn for future reference based on the rainfalls due to typhoon Morakot. The critical boundary lines were tested against two historical typhoons for validation. This research establishes a system which focuses on building an inventory for the bridges damaged by previous disasters in Taiwan. The system also stores information of possible factors which might relate to the damage, such as water levels, rainfalls, and near-by dams or reservoirs, and all the above information can be displayed by a geographical information system (GIS) in the system. Results of this research include (1) establishing evaluation processes of hazards of debris flows and flood scouring, (2) generating two critical boundary lines of rainfalls for hazards of debris flows and flood scouring, and (3) establishing an inventory of bridges damaged by disasters. These results should be very helpful for the bridge management agencies to take precaution measures for disaster prevention related to bridges.
