A convection-diffusion model to determine the position of heavy metal pollution source in topsoil

In order to research water pollution problem in soil or underground water and determine the position of metal pollution source of certain region, the convection-diffusion model to determine the position of heavy metal pollution source in topsoil is established based on solute migration theory and actual measured data of heavy metal content in topsoil of certain region combined with deterministic solute migration model. The model expounds the method of rotation of coordinates and numerical insulation using reference coordinate system which follows the movement of fluid particle, discusses migration law of soluble pollution in soil or aquifer in function of water flow and solves partial differential equation by least square method to determine the position of pollution source accurately.