Grey Differential Model of Groundwater Pollution

Contaminant transport in underground system usually occurs in varied flow fields and in anisotropic and heterogenous media. Because the applicability of analytical solutions is extremely limited for such conditions, and the distribution and transport of pollutants in groundwater are controlled by physics and chemistry and biology courses, which include advection, mechanical disperse, molecule spreading, adsorption, solve and suck, biodegradation function, numerical techniques are essential for underground pollution modeling. Among the numerical techniques, the gray numerical method has become very popular and is recognized as a powerful numerical tool. The gray numerical method, particularly for pollution modeling, may be preferable to other methods. In this paper, based on the grey theory, the velocity and dispersion coefficient and attenuation in groundwater are considered as uncertainty parameters and expressed as gray parameters. A grey differential equation of contaminant diffusion in groundwater is built. And the equation has special structure. The truncation error of finite differential method in solving the model is corrected. According to the model, distribution values of pollutant concentration under sudden pollutant discharged can be obtained directly, which can provide abundant and useful water quality information for the plan and control of water pollution.In this paper, gray numerical model is applied to simulate groundwater pollution. The results indicate that this method provides the references for the forecast of pollutants and the management and evaluation of groundwater resources.