Research Of Urban Flooding Numerical Simulation System And Its Visualization Based On Cloud Platform

With the global climate change and the enhancement of human activities,extreme rainfall events often occur in recent years.The disaster caused by urban flooding has attracted more and more attention,coupled with the increasing urbanization process.As an important tool to study the problem of urban flooding,the numerical model of urban flooding can provide an important scientific basis for disaster simulation and early warning.Scholars at home and abroad have done a lot of effective research on urban flooding model and software development,but there are not many software that can simulate the whole process of urban flooding,and there are very few independent intellectual property rights in China.The water conservancy numerical simulation system based on cloud platform has been emerging,but most of them are developed and built under the client/server(C/S)architecture mode.These researches do not make full use of the convenience brought by the rapidly developing network technology,and fail to reflect the advantages of cloud computing and the concept of cloud services.To solve the above problems,a set of urban flooding numerical simulation system based on cloud platform was developed in the mode of browser/server(B/S)with the help of HTML5,WebGL,cloud computing and other rapidly developing network technologies.The main research work and achievements are summarized as follows:(1)Based on the finite volume method,the two-dimensional shallow water equation high-resolution numerical model suitable for urban surface confluent flow simulation and the one-dimensional hydrodynamic model suitable for urban complex river network and pipe network flow simulation are established respectively.The coupling mechanism between the models is studied deeply,and the lateral and vertical coupling are realized.A more complete hydrological-hydrodynamic coupling model of urban flooding is established considering the effect of rainfall and infiltration,and the whole process of urban flooding is simulated.Through a series of simulation examples,it is proved that the model is reliable.(2)By using HTML5,JavaScript,WebGL and other technologies,a three-dimensional visualization system of flow field in the network environment is established from a three-dimensional perspective,which can display the flow field details of multi-element synchronous superposition in the browser.This paper presents a new method to display the results of hydrodynamic model calculation by using WebVR technology,and designs and develops a 3D virtual reality system of flow field.In this paper,a method of using texture styled particles instead of 3D sphere is proposed to optimize the performance of browser rendering flow field.Taking the three-dimensional visualization of the flow field in the Oujiang River Estuary as an example,the research results are proved to be of practical value in engineering.(3)According to the idea of front-end engineering and the open source ecological community,a 3D WebGIS solution based on Vue.js is proposed.Based on the results of urban flooding model and the visualization results of flow field,an urban flooding numerical simulation system is developed based on the cloud platform under the B/S architecture,which can complete the whole process of urban rain flood numerical simulation with the help of browser without installing software.The application of the research results in practical engineering is demonstrated in detail from the aspects of automatic modeling,remote computing,and flow visualization and so on.It is proved that the system can be effectively applied to the actual project of urban flooding from the two aspects of model simulation and system visualization.