A Study On The Grey Numerical Model Of Air Pollution

Urban air environment is a complex system with multi-objectives, multi-layers and multi-factors. Based on grey system theory, air environment systems are analyzed and in this paper an objective grey numerical model of air pollution is built to simulate air pollution diffusion of urban environment, which has a crucial practical significance to flexible management and decision making of the air pollution control.First, the concentrations of contaminations (SO₂ and NO_x) in the atmosphere of Handan city were monitored, and the statuses of the contaminations in the atmosphere were mastered. Meantime a new conception, air ground pollution belt is put forward, whose air pollutions diffusing equation was built. By means of finite difference method, the differential equation of air pollution diffusion is dispersed and got two-dimensional finite difference equation of air pollution. Meanwhile we finished the calculation process by computer program and validated the correctness of the numerical model, and analysed the connection between parameter of model and numerical solution, and protracted the concentration space of contamination diffusion under an unsteady state. In the respect of grey numerical model, introduced the basic theory of the grey mathematics, and analyzed these problems which were how to generalize and grey geohydrologic conditions, set up grey model, test and correct the model and apply model. Based on the foundation of the grey numerical model of two-dimensional finite difference equation of air pollution, tested two kinds of grey solving methods , proved the perfection and correction of the grey solving method.The results showed that the"white"grey solving method is a good and true"grey solution". As application of grey numerical model, a case was analyzed. In the case, the contaminations (SO₂ and NO_x) in the atmosphere of Handan city were simulated by the grey numerical model during heating times and unheating times, and worked out other simulation work by Visual Basic for Windows. It makes the grey numerical model achieve preferable application effect.