(Proceedings of Symposium HS3006 at IUGG2007, Perugia, July 2007. IAHS Publication 315, 2007, pp. 221)
Owing to the natural and social attributes of floods, assessment of integrated flood risks should include both technical and social assessments. When considering social assessment of risks, three questions typically arise: (1) how high is the ability of humans to endure risk? (2) what risk level is acceptable for humans? (3) to what extent can floods affect society? By considering the transient attribute of flood disaster risk both in nature and considering the transient attribute of flood disaster risk both in nature and society, this paper analyses the basic composition of assessment of integrated flood risks, which consists of risk of casualties of people, economic risk, environmental risk, and potential risks. The paper establishes an assessment index system for the Yangtze River and presents an assessment method for integrated flood risks basedon the Catastrophe Theory. By using an orthogonal formula, the calculation of each index is carried out from the lowest layer to the top layer according to the type of catastrophe to get a risk sequence of the Yangtze River basin during 19952000. The method offers an answer to the question: to what extent can floods affect society?
Catastrophe theory, Flood disaster, Integrated, Social assessment
