Improvement and application of vulnerability assessment methodology for flood hazards in China:using Changsha Prefecture as a case study

China is exposed to a wide range of natural hazards, including earthquake,flood,drought,and so on.The occurrence of hazards is not a phenomenon of recent time;however,understanding vulnerability,especially social vulnerability,is a relatively recent trend.In order to prevent disasters from happening,more attention should be paid on this changeful literature.This paper focuses on social vulnerability assessment,especially on constructing a social vulnerability index I_(sov).Based on Hoovering approach,a methodology with factor analysis and multiple regression analysis is proposed.By this novel methodology,a set of socioeconomic variables are reduced to a few independent factors,and a quantitative model of social vulnerability has been constructed.This model can assist decision-makers in better finding out the real driving factors and dynamic changes of I_(sov).There is a trial application to Changsha.All data are from 1980-2003.With this methodology,a dynamic process of I_(sov) in Changsha region is predicted,and I_(sov) of five districts and four counties in Changsha are compared.