| Unexpected environmental accidents have the characteristics of uncertainty, but now the accident research focuses on the emergency treatment later on, it is lack of about the accident forecast visualization simulation in the process of simulation.Research based on the dispersion modeling of pollutants in the sudden environmental incidents, analyses the affect factors of pollutant dispersion in the visual simulation and diffusion process in the study area. It can intuitive judgment pollutants diffusion process and coverage area,and put forward the corresponding emergency decision-making, It has important theoretical value and practical significance.The paper is" Technical Guidelines for Environmental Risk Assessment on Projects"(HJ/T169-2004).for the guidelines, using the classical Gaussian plume model for diffusion simulation model of predictive visualization of atmospheric pollutants, For sudden accidental explosion the radius of predict that is the Netherlands Organisation for Applied Scientific Research Institute TNO multi-energy method model, the modelparameter values using the on-site monitoring or perennial combination of the classicalmodel is calculated. To achieve a visual simulation of the procedure of calculation and response prediction, it use VB as a development language and GIS as a development platform. The main achievements of this thesis are listed as following:(1) Study on prediction model:By the proliferation of a variety of modeling methods of the present domestic and foreignsources of pollution leak. this paper determine the atmospheric diffusion emergency forecasting model for the " Technical Guidelines for Environmental Risk Assessment on Projects "recommend using the Gaussian plume model; radius of the vapor cloud hazards model to determinethe Netherlands TNO multi-energy method to determinehazard radius value.(2) Application of Visual Basic and GIS technology:This paper is VB as a development language, to achieve human-machine interface, fast parameter input window and the preparation of the model code to achieve the fast computation of the prediction model. In the window of parameters of pollution source determine the point source, line source and non-point source. The parameters of pollution source include the name of pollution, the type of pollution source, the discharge temperature of pollutant, the discharge rate of pollutant, the duration time of leak of contaminants and the height of leak of pollution sources. The environmental parameters include wind direction, atmospheric stability, environmental temperature, atmospheric pressure, the average speed of wind and temperature gradient. The type of output using Excel and GIS. Using ArcGIS emergency forecast visualization of the diffusion process map, find thesensitive point, the wind direction axis and the concentration of a section of a moment, using Origin to draw the trend of concentration changes.(3) Model using and the development of emergency response systems:In this paper a chemical company jiexiu city for object, by CH3OH and CH3Cl as the study of virtual unexpected environmental accident,and use Atmospheric dispersion model and VB-GIS technology to simulate the diffusion process diagram, and make a sensitive point, the axis of concentration and a section of amoment of concentration curves, To achive the model in time and space, and propose appropriate emergency measures. and by extension to our country’s existing prediction model of the emergency system and puts forward to the discussion of the direction of development of technical and methodological.(4) The innovation of technical methods:This paper Abandoned the often sudden environmental accidents, emergency treatment measures, instead of using the VB-GIS computer technology to the change of pollutant concentrationvalue of time and space in the diffusion process, the new formation on the suddenfatenvironmental emergency predict a more complete study of the visual simulation. |
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