Two-dimensional Simulation of Nitrate Transport in an Agriculture-intensive Region

A two-dimensional steady-state solute transport model is developed to simulate movement of non-point sources of pollution in anisotropic porous media. The migration of chemicals dissolved in groundwater is governed by advective-dispersive processes which are also affected by the velocity of the flowing groundwater. Therefore, groundwater flow equation is solved for hydraulic gradient and hydraulic conductivity to approximate the average linear velocity of the fluid. The advection-dispersion is used to approximate the spatial and temporal distribution of non-reactive dissolved chemical in a flowing groundwater. A computer code is developed in MATLAB to solve the groundwater flow and solute transports equations by finite difference methods. The developed program is verified with soil-tank experimental data. The solute transport model is used to simulate non-point source of nitrate pollution in an agriculture-intensive region. Finally, the model outputs are analyzed to understand the factors that influence the pollution transport in the study area.

Point and non-point sources of pollution, solute transportation, advective-dispersive processes, porous media, finite difference method.