Simulating 50 years of land management and groundwater flow

• Elevated nitrate (NO3) concentrations in both ground and surface water are a common problem in regions with intensive agriculture such as Flanders.

• Fertilizer restrictions have in many catchments been awarded with reduced NO3concentrations, but not everywhere. In catchments with substantial NO3-rich baseflow, the response may be delayed due to long travel times of historically contaminated groundwater travelling through oxidized parts of the aquifer systems.