Analysis of flood disasters from 206 BC to 1949 in China
Zhenhua Liu
Department of Municipal Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China, 310018
Flood disasters produces not only direct economic losses but also serious environmental problems, the government attaches great importance to flood disasters prevention from ancient times to the present. A variety of analytic methods are adopted, for example mathematical model analysis, chart analysis, qualitative and quantitative analysis. Some mathematical models are constructed by means of statistical analysis of historical data for flood disasters, such as mathematical model for flood cycle each dynasty. There are the following results. First, there are 1037 times flood disasters from 206 BC to 1936, once every 2.07 years. According to analysis of mathematical model for flood cycle each dynasty from 206 BC to 1936, the flood cycle is the declining concave curve, except for the Five Dynasties. Second, in modern history, the most number of catastrophic floods is the Yellow River reaching 8 times, the Yangtze River 5 times. Finally, water pollution caused by floods can not be ignored. In 2012 92 percent of untreated rural sewage was discharged dispersedly.The vast majority of pollution load on the ground runs into directly riverway through stormwater runoff. Water wells are easily contaminated for germs and parasite. We should pay attention to water pollution caused by floods and combine organically flood control with water environment protection.The government coordinates closely ideas, rule of law, technology and investment with rural residents for governing rural sewage to reduce the risk of water pollution caused by floods.