A GIS-based Research On Urban Vulnerability Assessment Of Flood

In the era of rapid urbanization, city has become the main concern of disaster mitigation around the world. Urban disaster has the characteristic of multiple kinds, complex reasons, severe impact, and delayed response, and it’s of most important to improve the ability of urban disaster prevention and mitigation for national security and sustainable development. Since 21st century, the process of urbanization in China has significantly accelerated, and the cities as densely populated area, are facing increasing risk of a variety of disasters. Yangtze River Delta region is widely distributed socially and economically developed cities, but it is also a flood-prone area. Therefore, it is a critical task to explore an effective way of food risk management for the alleviation of disaster impact in Yangtze River Delta region.Disaster is the result of interaction of hazard factors and vulnerability. Vulnerability is the premise to understand the essence of disasters and the field in which people can do something to make a difference in disaster prevention and mitigation. The hazard factors are difficult to control. Therefore, to decrease the vulnerability is the most effective method to reduce the losses caused by disasters.In order to improve the capability of flood-prone city to resist disaster, this paper carries out research on vulnerability assessment by establishing assessment index system and assessment model. This article draws extensively on the theoretical model of vulnerability domestic and abroad and discusses influencing factors of urban flood vulnerability on the basis of HOP model. After that, the paper chooses social and physical assessment factors with given weight and analyzes urban flood vulnerability by using comprehensive assessment model.Firstly, present understanding and research of disaster vulnerability is introduced, as well as the main assessment methods and conceptual models. Besides, the tendency of GIS application in disaster vulnerability and the community-based mitigation work in recent years is reviewed. On this basis, the paper chooses Gulou district of Nanjing city as object of study and establishes a spatial information database by using high-resolution remote sensing image and GIS tools. Meanwhile, three communities (Fuhougang, Mataijie and Dafangxiang) are chosen for exploring flood vulnerability assessment method at the scale of community. Then the flood vulnerability of Gulou District is calculated and illustrated in the map. The results show that:(1) of the total study area, area of high flood vulnerability accounts for 32.8% which mostly locates in the west and low vulnerability 33.6%; (2) at community scale, the spatial features of vulnerability could be reflected by population distribution; (3) The use of satellite data and GIS tools is efficient, comparatively easy to repeat and relatively low in cost per mapping unit. Finally, the characteristics of flood vulnerability of Gulou District are summarized and corresponding suggestions are proposed.