台灣現有淹水潛勢圖在洪水保險之應用探討

Abstract

灣的特殊地理位置和地形導致了每年遭受颱風洪水困擾，再加上高密度的人口與經濟發展，頻繁的天氣災害給民眾造成了巨大的財務損失。為減少洪災造成政府的財政負擔，可對淹水的高風險地區推行洪水保險。許多國家都有推行洪水保險，現以美國，日本等國家發展相對完善，台灣現行的颱風洪水險為火災附加險，並無完整的洪災保險制度。為訂定完善的洪災保險制度，需進行淹水地區、災損的探討。現階段淹水潛勢圖，並沒有對降雨延時進行太多的討論，雖有不同的降雨延時造成的淹水潛勢，但並不了何種降雨延時會造成最大的淹水。另雖有公佈淹水潛勢圖，但並無量化的淹水損失資料，以致洪災保險的推行困難。為更準確地評估淹水情形，本研究先利用三角形歷線，SCS歷線，和PRF三種出流歷線，製作了降雨延時-強度-淹水體積圖。探討不同延時造成之損失影響，另根據國家災害防救科技中心提供的新北市淹水圖（24h，48h）， ArcGIS軟體、淹水損失-深度關係，以三重區為例計算了各個鄰里的淹水損失面積和損失金額。藉此分析，進一步了解台灣現有淹水潛勢圖在洪水保險之應用可行性，並提出建構淹水潛勢圖，如欲配合作為淹水保險之基礎時，所需考量之建議，以作為未來相關分析參考。

Taiwan's special geographical location and topography results caused to many typhoon flooding problems, with the high density of population and highly development of economics, and frequent weather disasters caused huge financial losses for the public to afford. To reduce the financial burden caused by the floods, flood insurance can be considered in high-risk areas. Among all countries implemented flood insurance, United States, Japan are relatively well developed. existing typhoon flood insurance in Taiwan is an additional insurance of the residential fire insurance, which is not a sound flood insurance, so that flood areas and flood losses need to be discussed. Figures of flood potentials is made without carefully thinking about rainfall duration, as the figures provide the flooding depth of 24h and 48h ,but lack of the information of which rainfall duration causes the maximum flooding volume. On the other hand, the figures provide the areas of the city, as there are no data to quantify flood damages, flood insurance is difficult to implement. To assess the flood situation more accurately, first this study produced a Rainfall duration– Intensity-Flood volume chart with three kinds of outflow calendar line, including the triangle calendar line, SCS calendar line, and the PRF calendar line. Then based on the flood potential maps (24h,48h) of the New Taipei City provided by NCDR, using Arcgis software and the relationship of flood damages and flood depth, calculate the amount of flood damages and losses of each neighborhood area, taking Sanchong District as an example. According to this practice, this study expects to suggest a framework to construct flood map, on the purpose of utilizing them for issuance application.