Study On Some Key Problems Of Flood Management

In China, despite the problem of shortage of water resources is deteriorating, the flood disasters has also increased. With the purpose of realizing the sustainable development of disaster area and reducing the flood hazards, the paper established an integrated preventing and mitigating disaster system through analyzing problems of simulation of flood routing, flood utilization, establishing evaluation system of flood disaster, and decision support system of preventing and mitigating disaster of flood detention basin.With support of the national nature sciences fund project and the national 863 project, the paper obtained some achievements, as following:(1) Proposed simplified dynamic simulation method of flood routing based on the analyzing of topographic feature of flood detention basin.In China, the environment of flood detention basin has been more and more influenced by human after decades of rapid development; there are great changes for the land level degree and types of underling surface. However such changes will significantly impact flood routing. Because the terrain becomes gentler and the hard ground is rapidly increasing, the paper proposed a simplified simulation method of flood routing, established simplified simulating conditions, performed dynamic simulation of flood routing using mathematical morphology method, and finally calculated the submersed area based on GIS.(2)Taking flood utilization as purpose, the paper studied the influence of underling surfaces on rainfall-runoff.Based on the data of rainfall simulation, the paper respectively established the nonlinear relationship between influencing factors and runoff coefficient of rainfall flow using LM-BP neural network and improved LM-BP neural network based on genetic algorithm. The results demonstrated that two methods all can accurately predict change law of runoff coefficient under special conditions, so can provide scientific algorithm for predicting gross surface runoff yield.(3)The paper studied the objective of flood disaster evaluation, expounded integrated evaluating thinking, and established "self-recovering" thinking system and evaluation index system of flood disaster.The foreign and domestic researches of flood disaster have focused on various aspects, but not comprehensive enough. So the paper proposed the idea of "self-recovering" of disaster area, and detailed the process of occurring, developing, and disappearing of flood, and corresponded measures adopted by disaster area and outside in order to preventing and mitigating flood disaster.The purpose is to establish foundation for setting up the decision support system of preventing and mitigating flood disaster.(4)Established evaluating system of flood disasterIn order to provide decision support for preventing and mitigating flood disaster, and considering the characteristics of flood disaster such as frequent updating, huge contents, and various sorts, the paper designed flood disaster evaluation system in Web circumstance, combining MVC exploiting mode, and adopting middleware technology with AAF framework.