The Research On 3D Visualization System Of Dam-break Flood Routing

There are different levels of security risks in numerous reservoirs in China. And recently, frequent extreme weather makes dam-break flood easily, which causing large casualties and property losses. For understanding the flood routing mechanism furtherly and providing the effective auxiliary means for disaster reduction, how to make use of 3D geographic information technology and visualization technology, combined with the numerical simulation model, so as to express informations of flood routing, has important practical value.In this paper, the information display technology and real-time simulation of the dam-break flood evolution process will be studied. Aim to the expression of flood routing information and lack of basic geographic data, the Google Earth is used to construct our 3D geographic information system, which could provide rich geographic elements to simplify data process. And MIKE21, a free surface flow model, is applied to calculate to solve the problem of low precision. Besides, Python scripts will convert result data into KML files, and store information into MySQL database. Our system provides some functions by loading the KML files, calling database, combined with the Google Earth API technology. These functions include 3D scene roaming, the dynamic demonstration of evolution process, data management, flood information query. To meet the demand of real-time simulation, this paper puts forward an improvement strategy of fluid simulation based on two-dimensional smooth particle hydrodynamics. A kind of neighboring particles searching method based on dynamic grid is presented to reduce the search complexity. The combination of virtual particles and punishment method is used to handle boundary conditions. And we simplify the process to reconstruct fluid surface. With OpenSceneGraph, the real-time flood simulation in large-scale scenarios can be realized.Based on building the 3D visualization system of dam-break flood evolution, a small reservoir is used as an example to simulation. This example shows that our system can conveniently show the dynamic process of flood routing, provide interaction query of evolution information and other functions. Besides, the system can gain more visually information of to show the details of evolution process, which provides more effective technology to analyze for the relevant researchers, and auxiliary decision support for flood control and mitigation.