The Study Of The Flood Disaster Risk In Nanning City

Nanning city is the capital of Guangxi province, and it is also the political, ecnomical and cultural centre in this region. Flood disaster happens high frequently, and it causes much disaster loss which restricts the continuable development of the city. The article studys the flood disaster risk based on Nanning city which is referenced and practical significance to constitute the policy of controlling flood and reducing hazard.The article explains the basic characteristic and content of the flood risk analysis; introduces the nature and socieconomy character of Nanning city, and analyses the cause of the flood disaster in the side of the nature and the behavior of the human and the projects preventing and controlling flood. Considering the random uncertainty of the height of the dike top and the wind and making random variables to be normal distribution by the method of JC , the article calculates the risk rate of the flood flowing over the dike in Nanning city and the relation of the flood frequency and the risk rate, and analyses the fuzzy risk rate according to the theory of the fuzzy mathematics; estimates the loss of life using the method of the experience analysis, and establishes the relation of the forecast alarm time and the life loss; based on the statistics data of the past flood disaster, predicts the flood loss using the method of the flood disaster recurring in the some future year, establishes the relation of the flood frequency and the economy loss, and this method is extended to the other regions ,and analyses the benefit preventing and controlling flood of the dike, and using the analysis method of the permissibility risk, analyses the risk value of the flood disaster; carries out the method of assessing the classification of the flood disaster loss, and confirms the weight of all indexes using the AHP method, and assesses the classification of the disaster loss of the "2001.7" flood in Nanning city by the fuzzy pattern theory, and this method is applicable in assessing the classification of the other disaster loss. In the end, according to the study result of the article, it carries out the strategy thought of controlling flood and reducing hazard combining with the actuality of controlling in Nanning city.