近年來發生於都市地區的水災,所造成的損失與影響程度卻有更較以往的水災嚴重的趨勢,而由於國內水災研究長期以來,多注重自然異常氣候現象與河川本身的自然易致災性的研究,較缺乏對於人文系統的了解,因此較難以因應近年水災災情的變化。本研究的目的為歸納至今都市地區水災的現象,以及探討過去數十年都市化過程產生的人文易致災性與其對水災的影響。 本研究包含兩個主要的研究主題,即「都市水災」與影響都市水災的「人文易致災因子」,前者以近40年來台北盆地內26場重大水災事件為對象,以水災轉變的比較分析與案例研究的方式討論台北盆地的「都市水災」特性現象;第二個部分則以近年水災頻傳且急遽都市化的汐止地區為例,建立一可結合航空照片、統計資料、淹水損失估算、洪峰增加率計算的模型,模擬三個不同時期汐止地區的都市發展狀態(民國75年、83年、90年)及其對應的水災事件(琳恩颱風、溫妮颱風、象神颱風),比較分析都市化產生的人文易致災因子。 研究成果摘要如下:台北盆地民85年後的水災,其特性如型態、淹水位置、災情皆顯現出「都市水災」現象,與其他亞洲都市如東京、福岡、漢城相同;都市化造成四項主要的人文易致災因子,分別為土地開發方式、防洪公共工程、資產密度、資產抗洪能力,這些因子皆具有增進都市招致災害可能性,使都市承受災害的能力下降,並隨著都市化過程累積的特性。
Recent years, impact of flooding damage in urban area is getting more serious and complicated than the past. However flood research in Taiwan emphasizes on natural hazards and natural vulnerability of rivers rather than human system in structure of natural disasters. The aim of this study is to generalize characteristics of happening flood disasters phenomenon, and to find out human vulnerability factors accumulating through decades of urbanization and those effects toward floods in order to response happening disasters. Therefore, this study contains two research topics, “urban flood” and “human vulnerability factor” toward urban flood. In the first part, disasters history research is adopted for discussion of “urban flood” by analysis of 26 major flood events in Taipei Basin since 1960 to 2000 and case study. The second part takes disastrous and rapidly urbanized Shijr area as an example, analyzes each “human vulnerability factor” through comparison between simulating development conditions (1986, 1994, 2001) and corresponding typhoons (1987 Lynn, 1997 Winnie, 2000 Xangsane) in three different periods of time in a model which can integrate aerial photo maps, data resource, damage loss estimation and peak flow increase rate calculating. It concludes that: flood disasters in Taipei Basin since 1996 gradually reflects “urban flood”, and the characteristics such as flood types, inundated locations and flooding damage are also shown apparently in certain Asian city like Tokyo, Fukuoka and Seoul; furthermore, “human vulnerability”, which might arouse possibility of flood disasters, weaken ability against flood disasters, and accumulate through urbanization of its character, contains four main factors cause of urbanization as follow: way of development, public flood-control construction, density of property spatially, ability against urban flood of property.