Simulation And Visualization Of Water Pollution Diffusion In The Nanjing Central Island Of The Yangtze River

A large amount of pollutants will be released in a water pollution accident with the characteristics of evolving rapidly, dealing with difficulty.It is destructive and a serious threat to the health and safety of the people. Especially in recent years, sudden water pollution incidents are frequent.Establishing the system of water pollution emergency response support, realizing the regional prediction of contaminant transport-proliferation as well as concentration of temporal and spatial distribution of inversion, have become imperative in order to provide regulator for water pollution decision-making basis.Nanjing Central Island of the Yangtze River located in the Nanjing section-of upper reaches of the Yangtze River. There are large amounts of industrial waste-water, domestic sewage and with many polluted rivers flowing into, crosssing outlet along the coast, which seriously threaten the safety of drinking water. Jiajiang water serves in this section is an important local source of water. Once the water pollution incident occurred, it will have a severe impact on the local residents’ normal life and the order of production. Therefore, it’s relevance and urgency to realizethe simulation, forecasting, dynamic simulation and emergency responseof sudden water pollution accident in this region.This paper serves Nanjing Central Island of the Yangtze River as the study area. What’s more, it is based on numerical simulation technology and model, the integrated technology of GIS as well as the technique of dynamic simulation to interpret the processes of transportation and diffusion about water pollutant intuitively. Its contents include as follows:(1) The contruction about concept modeling of Nanjing Central Island of the Yangtze River. According to the natural conditions of Nanjing Central Island of the Yangtze River, based on the principles of visual conceptual modeling, building the concept of Nanjing Central Island of the Yangtze River from the physical layer, spatial relationships, scene layers, abstract and simplify the geographical environment and provide the basis for the simulations of numerical model.(2) The numerical simulation of the combination of soluble and non-soluble pollutants. Based on the study of the processes of physical flowing movement and the characteristics of water environment, calculating and simulating the flow field of Nanjing Central Island of the Yangtze River under the action of wind and water. Then simulateing the processes of transportation and diffusion of dissolved contaminant based on the models of water quality; The paper also portray the drift track of the insoluble pollutants (such as oil spills from vessels) according to particle tracking models and stochastic models.(3) The analogue simulation of diffusion of water pollution. Through the visualization technology of the diffusion simulation about basin water pollutant, we do the modeling simulation of pollutant concentrations for different working conditions andrapidly realizethe regional prediction of contaminant diffusion and the inversion of concentration distribution and provide important reference for accurate prediction of the scheduling decisions of river pollution emergencies in water pollution processes.(4) The building of diffusion and analogue simulation system of Nanjing Central Island of the Yangtze River water pollution. We design and develop the diffusion and analogue simulation system of Jiajiang water pollution, combining simulation and prediction of the needs and characteristics of GIS. Formulate a specific system of GIS-based plug-in framework, use the model of loose-coupling mechanism adjustment, use ArcEngine components to provide the functions of interactionwith the map and querying and use the third party visualization tool libraries VTK for rich and beautifuldynamic visualization based on reflections.