台灣每逢夏秋兩季,颱風豪雨便常常造成局部地區之災害發生,尤為河川之下游區域及低窪地區,飽受淹水之苦。每當颱風豪雨時,往往造成人民之生命安全及經濟活動之傷害。因此,若能在災害發生前提供預警參考,以降低淹水災害之損失及威脅。 本研究利用FLO-2D 淹水模式以2005年至2009年間五場颱風豪雨事件之降雨量來模擬曾文溪之淹水情形,再以地理資訊系統(GIS)圖層套疊出淹水鄉鎮範圍,並與實際淹水調查情況比較,作進一步分析探討;且由淹水模擬結果,提供未來在淹水模式選擇上之參考。此外,以模擬結果擬定一簡易之淹水預警研判機制,以控制點集水區24小時設計雨型,在一級、二級警戒水位條件下,分析當地可能發生淹水之雨量警戒值,最後即可進一步建立某一警戒水位下之降雨延時-雨量警戒值之關係。 模擬結果顯示曾文溪流域之易淹水區為官田區、大內區、善化區、麻豆區及山上區等。而控制點集水區在一級、二級警戒水位下,1、3、6、12、24小時之警戒雨量值分別為67mm、73mm、78mm、85mm、95mm及118mm、127mm、137mm、144mm、165mm。
Taiwan during summer and autumn, typhoons often cause heavy rain in some areas it's a disaster, especially the lower river area and low-lying areas suffered the pain of flooding.Whenever a typhoon rainstorms, often resulting in people's lives and economic activities of the injury. Thus, if the pre-disaster to provide early warning information, in order to reduce disaster losses and the threat of flooding. In this study, FLO-2D flood model in 2005 to 2009, five typhoons and heavy rainfall events to simulate rainfall flooding Tsengwen the case, then geographic information system (GIS) layer overlaying a range of flooded towns, investigation and comparison with the actual flooding, for further analysis to explore; and simulation results by the flooding, in flood mode provides the choice of the future reference. In addition, in order to develop a simple simulation of flood warning judged mechanism to control the point of the catchment area 24 hours design storm, in the first, second warning level conditions, the analysis of possible flooding of the local rainfall warning value, the last that establishing a warning level can be further under the rain delay - the value of the relationship between rainfall warning. Simulation results show that the Tsengwen River flood prone area as mandarin area, within a large area, Shanhua area, Madou area and mountain areas. The control point in a catchment area, two under the warning level, 1,3,6,12,24-hour alert rainfall values were 67mm, 73mm, 78mm, 85mm, 95mm and 118mm, 127mm, 137mm, 144mm, 165mm .