Research On Simulation Of Gaussian Plume Model Of Atmosphere Dispersion Based On GIS

With the rapid economic development of Shanghai, the pace of industrial and agricultural production is accelerated in recent years and various air pollution problems follows, especially emergency air pollution. The occurred emergency air pollution probability heightened which still seriously threaten the lives of the local people. Hence, promotion the research and development and strengthen the emergency monitoring are of great importance work in environmental protection.The atmospheric pollution dispersion model is a kind of time and space complex-type environment models that describes the transportation, diffusion and dilution of atmospheric pollutants and it is a powerful measure for environmental assessment and prediction. In the past years, emulation technology was widely applied in systems that simulate and analyze serious air pollution incidents through establishment of mathematical models both at home and abroad. But, these systems are difficult to integrate specific business systems with the EPA because of their professional platforms.The methods and theories of some atmospheric dispersion models were firstly discussed in this paper, as well as their advantages and disadvantages. On the basis of our laws and regulations under the application-level, Gauss model was chosen to simulate space-time concentration distribution of atmospheric pollutants.Subsequently, the basic principles and methods of Gaussian model are highlighted in the next section. In the emergency air pollution incidents, instantaneous exhaust emissions are usually influenced by the wind direction and speed to form plumes in the atmosphere. And the place where accident occurs is often as the coordinate origin in the Gaussian model. To solve above questions, Gaussian plume dispersion model was exploited to simulate and predict the concentration distributions of air pollutants for Dachang zheng in Baoshan District, the famous chemical town. Consequently, simulation of the emergency air pollution dispersion in Dachang zhen was implemented combining with Gaussian plume model and GIS tightly. Several approaches were conducted. (1) To customize various dispersion parameters and conditions by users, such as atmospheric stability, underlying surfaces, lateral dispersion coefficient and so on. (2) To determine the place accident occurs as a coordinate origin and establishes Gaussian Plume coordinates. (3) To transformation from Gaussian coordinates to Geographical coordinates. (4) To screen calculation points using fan-shaped graphics. (5) To calculate value of points based on Kriging interpolation method. (6)To protract concentration contour.