Vulnerability Assessment Of The Rainstorm Floods In Pudong Of Shanghai Based On The Scenario

With global climate change and rapid urbanization process,natural disasters have been being major issues and severe challenges which human society and economic development faces. There is a high concentration of population and economy in the urban regions, so might cause great loss by natural hazards. Floods are one of natural hazards with high frequency, wide damage,high disaster. With the increasing floods with frequency, intensity and breadth, how prevention and mitigation of disasters become a hot issue which international society common concerns now. In fact, it shows that pre-disaster flood risk management is most important, which is also the most important basis to take policies and measures for disaster prevention and mitigation. Vulnerability assessment is important basic ways of risk assessment, which is an important basic research of international disaster prevention and mitigation.The paper utilize a revised SCS model to calculate heavy rain runoff in Pudong New District for the six return periods which are 20 years, 50 or 100 years, 200 years, 500 years and 1000 years. According to DEM of Pudong, we result in the water depth of submerging for different return periods, there is respectively: 3.78m, 3.91m, 3.98m, 4.02m, 4.06m, 4.09m. Base on the grid, we re-classify and extract the inundation depth maps for different return periods. Combined field surveys with exit references of the disaster loss rates for natural residential village, farmland, industrial and warehouse land-use, public land-use in different submerged depth of water, we map the overall vulnerability level distribution of four types of land uses in six return periods.Through vulnerability maps of six return period, we result following: (1) The scope and intensity of the vulnerability of heave rains flood is increasing from 20 to 1000 years, while 200 year return period flood vulnerability is a turning point, and Influencing areas of vulnerability are alsoincreasing rapidly;(2)The overall vulnerability of Pudong New District at different return periods shows only low and high level vulnerability areas, due to the classification of vulnerability level. While from 20 to 100 years, the level of vulnerability is among the low, middle and high vulnerable areas, for high where mainly distributed in the town of Gaoqiao, Gaoxing,Beicai, Zhangjiang, Heqing, Chuansha, for low vulnerable areas are mainly located in the streets and near high vulnerable areas; From 200 to 1000 years, the areas of vulnerability of four kinds of land use accounted for 26%,30% and 32% of the Pudong New District. Middle and high level areas mainly locate in the towns of Pudong,low level areas are mainly along the streets of Pudong. (3) Through analysis of four kinds of land-use, vulnerability levels for six return periods are:â‘ farmland is always high vulnerable zones at six return periods ;â‘¡middle vulnerable areas are natural residential villages from 20 to 100 years; low vulnerable areas are located in industry and warehouse land-use, and public land-use;â‘¢200 to 1000 return periods, middle vulnerable areas are located in natural residential villages and a small part of industry and warehouse land-use, and public land-use; but low vulnerable areas are mainly located in industry and warehouse land-use , and public land-use. According to the situation of the Pudong flood vulnerability assessment, the paper puts forward specific countermeasures and measures to reduce the vulnerability of floods in the Pudong.