Impacts of land use and flow on nitrate concentrations and fluxes of an upland river system in north east Scotland

The effects that an altered flow regime may have on mean annual nitrate concentrations and fluxes in a sub-catchment of the River Dee, N.E. Scotland are assessed. During the wettest year in the recorded history of the subcatchment, the mean annual nitrate concentration increased at most by 16% but fluxes increased by upto 50%. A simple model has been developed to relate the concentration and flux to the percentage of cultivated land and flow. The model provides estimates of the maximum and minimum concentrations and fluxes for a given proportion of cultivated land.