Managing the effects of agricultural practices on groundwater quality

The development of methodologies able to study and to protect groundwater from contamination is an important task. The tools should have the character of managing instruments and be innovative with respect to the conventional modeling of nitrogen transport in groundwater. The methodology, proposed in this paper, is based on a mathematical model describing both water flow and nitrogen migration in saturated and unsaturated part of an underground domain. The mathematical model is governed by two equations describing the two-dimensional water flow through a porous matrix in a vertical plane and the transport and dispersion phenomena in the unsaturated and saturated zones. The equations are solved numerically using a finite difference approach. The model is applied to a study area, which comprises a part of the Po river basin, south of Modena, bounded by the Secchia and Panaro rivers, both tributaries of Po. This area is intensively used for civil, industrial and agricultural purposes and intensive cattle and pig breeding takes place on the south section of the study area. The influence of the agriculture is focused on the groundwater quality resulting in high nitrate concentrations that reach unacceptable values.