Modelling nitrate transport in deep aquifers: comparison of model results and field measurements

The nitrate distribution in deep aquifers is being studied. Simulations were carried out for a study area in the cast of The Netherlands (40 x 30 km(2)). Model results are compared with data from the Groundwater Quality Monitoring Network. Based on preliminary runs modifications in the model are proposed. In a second series of runs these modifications are evaluated. A major factor is the vertical nitrate distribution. The steep vertical concentration gradients shown by the field data can only be simulated if vertical dispersion is reduced to the level of molecular diffusion. Several setups of the denitrification parameter arc considered.