Research On Risk Assessment And Management Measures Of Flood Disaster

The flood disasters occur frequently in our country, caused enormous loss of life and property, become a serious threat to the stable development of economy and society. To mitigate flood damage and reduce the flood risk, realize the change from flood control to flood management, the comprehensive use of the flood control engineering measures and non-engineering measures is needed. Flood disaster risk assessment can be fully grasp the regional flood situation, have important value to improve public risk consciousness, standardize the rational land use, promote the scientific decision of engineering measures with non-engineering measures. In this paper, based on the existing theory of flood disaster risk assessment, taking the downstream section of Fuzhou River as study area, combining flood numerical simulation methods and geographic information system, evaluated the flood risk from flood disaster hazard and vulnerability these two aspects, and developed appropriate risk management strategies.This article studied the flood disaster systematic theory, analyzes the environment of causing the disasters and natural causing disasters factors and disaster bearing bodies according to the flood disasters systematic theory, also studies the flood hazard, exposure and vulnerability of disaster bearing bodies. Analyze the commonly used methods of risk assessment, choose the numerical simulation method combined with geographic information system for flood risk assessment in the study area.Evaluate the flood hazard applying the numerical simulation method and historical flood method. The numerical simulation method bases on the design flood data and terrain data, the four frequency (0.5%,1%,2%,5%) flood simulation models is built. Taking the inundation depth of simulation results as the main index to evaluate the flood hazard of the study area, the hazard distribution of different flood frequency can be obtained. In addition, the historical flood investigation were conducted, using the2012storm flood level marks and DEM data in ArcGIS, the water depth distribution and flood hazard assessment of the typical historical flood can be finished. The assessment results show these two methods applied in the flood hazard assessment has obtained a good effect.According to the grid thought flood vulnerability is discussed based on GIS. Through the interpretation of satellite remote sensing images and topographic map the land use type and distribution are determined, combined with the flood inundation, the dry land, paddy field, garden land, residential land, land for fisheries, mining land six types of disaster bearing body is chosen. through on-the-spot investigation and reference other research results determined the flood loss rate of the disaster bearing body, combined with the depth of the water distribution data the vulnerability assessment can be completed in ArcGIS, flood vulnerability distribution and its change trend can be obtained. A estimation method of flood losses is discussed by estimating the value of per unit area of disaster bearing body, taking dry land as an example, calculated the flood losses of four different frequency flood.Finally, the current flood disaster risk management measures are discussed in this paper. On the basis of risk evaluation, plans dealing with flood emergencies are made; The point-line combination method is applied to flood evacuation analysis, considering flood water depth, time of arrival, the affected villages distribution, road, etc, the best evacuation route of the village can be calculated by the GIS network analysis function, also the evacuation time of each route can be obtained. These information provide a scientific reference for flood emergency actions.