Study On The Theory And Application Of The Evacuation Decision-Making For Preventing Flood Disaster

The flood disaster loss is the most serious calamity in all natural calamity of our country. With the development of urbanism and society-economy, the loss caused by flood is more and more serious. The paper study the basic principles of the flood calamity assessment under GIS, flood calamity evacuation and evacuation decision based on analysis of the property feature and mechanism of flood calamity aroused break-dam.The break-dam flux is calculated by Fread formula based on analysis of the mechanism of break-dam. The connectedness of flood submerging region is analyzed by using boundary tracking based on 8-connected. Based on the result of boundary tracking, the coordinate positions of boundary points are found. After boundary points in group are dealt by sequence, area filling can be completed. Distance in the mathematical morphology is applied in flood spreading, and the distance from one point to place of break-dam in the flood submerging region can be calculated. The flood submerging range and depth are simulated by using flood submerging model based on DEM and flux of break-dam. The idea of flood disaster analysis based on "point-line combination" is put forward. The roads are regarded as "line" in the large area of flood submerging range; The submersed villages and refuges are regarded as "point", and the submersed villages are regarded as start-point, refuges are regarded as end-point. A random model is put forward to calculate the road right based on characteristic of evacuation, the static road model is simulated by Dijkstra algorithm. The concept of wagon flow random degree is introduced in dynamic route analysis, and according to this random degree, warning levels are plot out three grades, which are showed by green, yellow, red signal lamp. The road right is calculated again based on warning level. Based on characteristic of flood disaster evacuation, principles that refuges are not affected by flood, victims do not need evacuate frequently, and refuges near some traffic hinges are put forward. The sustainable development mode of refuges under the nature-manpower duality is put forward based on existent problems in developmental process of refuges. Based on jieke theory, jieke theory of evacuation resettlement area system is put forward, and numbers of victims that enter into resettlement area are restricted by on-off model of jieke. The subjective weight and objective weight, i.e. AHP and entropy method,are combined together as synthetical evaluation index in flood disaster evacuation synthetical assessment model. According to GIS use in flood disaster evacuation system, the projects that satisfy some limited conditions are picked out through the overlay algorithm of hierarchical maps in GIS. The theory and basic concept of matter-element model and fuzzy similarity nearness degree are introduced, fuzzy similarity nearness degree matter-element model is applied for selecting the optimal scheme. Final, the paper outlines some aims principles and guidelines for developing DSS, and data base, model base, knowledge base, method base and text base, from point of view of combined GIS with DSS. The whole frame of the Changxingdao flood disaster evacuation decision system based on GIS is established, which provides foundation for further study.