Numerical simulation of groundwater flow and nitrate transport in an agricultural watershed (New Brunswick)

Agricultural practices are one of the largest anthropogenic sources of groundwater nitrate contamination. Nitrate is a major source of contamination because of its high mobility and persistence in the environment. In the present study, agriculture-groundwater interactions in a portion of the Black Brook watershed in north west New Brunswick are investigated.; Nitrate transport is simulated using a numerical modelling approach that links GIS, a lumped parameter root zone model, and a three dimensional flow and transport model. Climate and land use data are used in the lumped parameter model to compute the concentration of nitrate leaching from the root zone. The results obtained are used as input for the flow and transport model ( FRAC3DVS), which predicts the concentrations of nitrate at monitoring wells as a function of time.; The modelling approach is used to investigate the impact of several hypothetical land use changes in the subwatershed containing the Village of St. André municipal well. (Abstract shortened by UMI.)...