Population Risk Dynamic Assessment For Flood Disaster Based On Multi-agent Simulation

Flood disasters including flood and waterlog have always been one type of disasters that bring the most serious loss to the world including China, and have an inestimable effect on lives and properties in China, as well as having resisted and restricted the healthy development of society. When facing with flood disaster, the government at-tempts to analyze, identify and predict each stage of the whole process of flood disaster based on the obtained disaster information, such as dynamic development trends, dis-aster risk and situations, etc. Meanwhile, emergency rescue measures will be adopted for each stage of flood disaster, in order to maximum the effect of rescue measures and minimum the loss of disaster. Therefore, risk assessment, especially population risk assessment of flood disaster is an important basis for government to make decisions on emergency rescue. Because of the complex dynamics that presented on disaster risk in the whole process of flood disaster, it would have a very important practical significance on dynamically assessing the population risk.Flood disaster is a typical "Nature-society" complex system, that consists of haz-ard environment, inducing factors and hazard-bearing bodies. From the perspective of system, the risk including population risk of flood disaster is the result on the macro, resulting from the interacting mechanism among components of flood disaster system. Therefore, applying Multi-agent Simulation (MAS) method of complex system model-ing method to population risk assessment of flood disaster is an important development direction of risk assessment. The MAS applies modeling method on the micro to model the complex system of flood disaster in a way of "from bottom to top". Through accom-plishing modeling each component of system on the micro, the macro attribute (popula-tion risk) of flood system could be presented from the whole. More importantly, MAS could organically combine the existing risk assessment achievements with the solving on dynamic assessment on population risk. Under the premise of considering the com-plexity and dynamic of system, applying MAS to construct the complex system of flood disaster and dynamically assess the population risk will be the keys and difficulties of this paper.Based on the existing research achievement on risk assessment and the studying on the features of flood disaster, this paper models each component of the complex system, that results into generating four kinds of agent:agent union of hazard environment, agent union of inducing factor, agent union of hazard-bearing body as well as agent union of risk analysis. Also, the interior structure and procedure of each kind of agent and the communication mechanism among agents are respectively designed. Studying on rainstorm-type flood, given the rules of agents of the system that satisfy rainstorm-flood scene, the population risk dynamic assessment model of rainstorm-type flood is built. Considering Lushan County, Henan Province as the studied area, the population risk of the whole process of rainstorm-type flood will be dynamically simulated and the simulation results will be analyzed and evaluated, for verifying the effectiveness of the constructed model in this paper.The research achievement of this paper could effectively reveal the dynamic changes of population risk in the whole process of flood disaster, and this method has a broad prospect.