淹水潛勢區之風險分析

Abstract

近來來，全球氣候異常，台灣也深受其害，於夏秋兩季之颱風與豪雨常常造成嚴重的淹水災害進而危害到居民的生命和財產安全，極端水文事件所造成之危險程度和人口數、社會經濟發展呈正相關，因此本研究希望透過風險地圖，提供非工程的解決方法，來達到降低災害的效果。 過去台灣所繪製之淹水潛勢圖，資料只有淹水深度以及淹水範圍這二項，於災害應變時，不容易判別淹水區域是否為受災區域，因此本研究參考不同的風險分析文獻，加入危險度與脆弱度的概念，定義風險等於危險度和脆弱度的乘積，從生命面向著手探討不同的危險度與脆弱度因子對災害的影響，並將不同重現期的淹水模擬結果製作出危險度與脆弱度地圖，並且運用半定量之風險矩陣繪製出風險地圖。 本研究以台南市三爺溪區排作為此次生命面向之風險評估地區，並以村里為最小單位，採取10m的網格，分析六種重現期(2年、5年、10年、25年、50年、100年)，最後分析出高風險村里的分布，以此防災風險地圖作為各機關設置避難路線之參考規劃，提供決策者對淹水災害的預警和發布消息的依據，也能成為位於高淹水風險區域之居民自主防災之資訊來源。

In recent years, Global climate anomaly, Taiwan also. Typhoons and heavy rainfall often cause flooding that result in serious losses of life and property in summer and autumn. The population and development of socio economic is related to hazard of extreme weather. Therefore, this study use non-engineering methods to reduce hazard by risk map. Flood map of Taiwan only have water depth and inundation area in the past, it is difficult to recognize where is the disaster area, therefore, this study reference different research of risk analysis, adding concepts about Hazard and Vulnerability. Delimit Risk = Hazard cross Vulnerability, and use different return period inundation model to produce Hazard map and Vulnerability map.Then, use semi-quantitation risk matrix to produce Risk map. The drainage systems in the Sanyei in Tainan are taken as a case study. Use SOBEK model with a regular grid in 10m resolution, and simulates the return period 2-year, 5-year, 10-year, 25-year, 50-year and 100-year in village level to get distributed of high risk village. The analyzing results can help the city government to realize the most risk area to reduce rescue time, and also let people who live in the high risk area have information to prevent disaster.