Zoning Of Flood Disaster Risk In Zhejiang Province Based On GIS

Flood disaster is one of the most serious natural disasters. In the world, the economic losses which flood disaster has caused account for about 40 percent. During a hundred years, the number of casualties which flood disaster has caused is more than 9 million. China is one of the countries that often suffer severe flood disaster. In the second half of the 20th century, flood disaster is severe in China, and China is generally suffered severe flood disaster in some years. After 1980s, flood disaster happened frequently, and especially in 1990s, a major flood disaster happened every two years, and the trend was quickly developing. Zhejiang Province has a complex geographical environment, complex topography, precipitation on the nonuniformity of space, the imbalance of time, and the instability of inter-annual. Flood disaster is prone to happens in Zhejiang Province. Zhejiang Province has suffered floods in many years. Flood disaster, especially large floods, can make the flood plain a few years of economic recession, or even ten years. At the present, flood disaster has a increasing trend, and is one of the important restricted reasons to the social economic sustained development in Zhejiang Province.Risk regionalization of flood disaster is an effective non-engineering measure for flood control and disaster prevention which can change from passive position to active position. As an important component of the flood control and disaster prevention system, risk regionalization of flood disaster helps Ministry of Flood Control make a science decision, and effectively avoid the danger, and it helps Ministry of Water Resources make the flood control standards and plan the construction of flood control projects. It can provide technical guidance and serves about flood control and disaster prevention and avoiding-danger for the urban construction, land planning, the production and operation in all industries, people's living and so on.Based on the analysis of natural environment and human environment background in Zhejiang Province, according to the natural disaster system theory, this paper selects evaluation indicators separately from the disaster environment, natural disaster index and body for disaster. From the meteorology, geography, disaster science, environmental science and so on, this paper takes lots of factors such as precipitation, topography, water, GDP and cultivated land into accounting, and make use of AHP method to give weight to each factor. The regionalizing map of flood disaster and the flood vulnerability map in Zhejiang Province are obtained by the spatial analysis of GIS. Through the overlay analysis of GIS for the regionalizing map of flood disaster and the flood vulnerability map in Zhejiang Province, according to the principles drawn up by regionalization, Risk regionalizing map of flood disaster in Zhejiang Province is obtained through data processing for the property database.