The Design And Implementation Of 3D Simulation System Of Qingyi River

China is facing four issues about current water environment,including much more water?less water?muddy water and dirty water,which come behind with the rapid development of social economy and the impact of human activities.Water pollution problem is becoming more and more serious among these issues,once occurred,it can bring great damage to social stability and economic development.The key to the prevention and emergency treatment of water pollution accident is the simulation and prediction of water quality,the current water pollution accident emergency system is mainly based on one or two dimensional water quality model and express the results through two-dimensional visualization technology.With the development of the threedimensional water quality model and 3D GIS technology,it is necessary to explore the integration method of 3D water quality model and 3D GIS technology,thereby develop a more authentic and accurate three-dimensional simulation system of water quality.Therefore,this paper designs and develops three-dimensional simulation system of Qingyi river water quality,based on the research on the construction of threedimensional water quality model and study area 3D scene?the simulation of water pollution accident and the 3D visualization technology of simulation results,take the area from north ring bridge to Beijing,hongkong and macao high speed as an example.The main contents of this paper are as follows:The basic sports forms of pollutants,the derivation of three-dimensional water quality and the construction of three-dimensional water quality model have been studied in this paper based on the analysis of a large number of literatures,at the same time,the three-dimensional GIS theory?the development platform and the method for three-dimensional GIS are studied and this paper explores the in the integration of these two aspects.The three-dimensional scene of study area is constructed from the terrain and feature two parts,they are constructed by using SketchUP and 3D max modeling software respectively,according to each ones characteristics,then achieve the flow of data between ArcGIS and the software,finally,realize the visualization of threedimensional scene of the study area in ArcScene.The method which is based on the center line vertical line is proposed to realize the grid division of the river surface,based on the analysis of the three-dimensional visualization of river,and then through the inverse distance weighted interpolation algorithm to achieve the river grid elevation interpolation,and ultimately to achieve three-dimensional visualization of the river.According to the measured river profile data and the riverbed data,the river profile is drawn and subdivided by GDI,and finally the three-dimensional visualization of the river profile is realized with the combination of terrain and feature model.The construction of river coordinate system is analyzed and studied to realize the conversion of river surface and profile grid from geographical coordinate to river coordinate system.Firstly,the pollutant concentration value of the grid is calculated through the three-dimensional water quality model,according to the coordinate of river grid in the river coordinate system,and then render the grid according to the water quality standard to realize the three-dimensional visualization of water quality simulation in the study area.Finally,setting the observation time and time interval and realize the three-dimensional visualization of water quality dynamic simulation of Qingyi river by sequence snapshot method.Finally,this paper takes Visual Studio 2012 as the development platform,C# as the development language,SQL Sever 2008 as the database,ARCSDE as the spatial database engine combined with the ArcGIS Engine 10.0 and carry out secondary development,and develop the Qingyi river water quality there-dimensional simulation system,taking the actual data of the river as an example,and the three-dimensional visualization of dynamic migration pollutants is realized.After the trial run,the system has a good three-dimensional visual expression and analysis capabilities.