Successful reduction of diffuse nitrogen emissions at catchment scale: example from the pilot River Odense, Denmark

0

Courtesy of IWA Publishing

Land-based total nitrogen (N) loadings to Danish coastal waters have been markedly reduced since 2000. This has been achieved by general measures reducing discharges from all point sources and N leaching from farmed land supplemented with more local and targeted mitigation measures such as restoration of wetlands to increase the catchment-specific N retention. In the catchment of River Odense, restoration of wetlands has been extensive. Thus, in the major gauged catchment (485 km2) eleven wetlands (860 ha) have been restored since 2000. A comparison of data on N concentrations and loss from a gauging station in the River Odense with data from a control catchment (772 km2), in which a significantly less intensive wetland restoration programme has been undertaken, showed an excess downward trend in N, amounting to 124 t N yr−1, which can be ascribed to the intensive wetland restoration programme carried out in the River Odense catchment. In total, the N load in the River Odense has been reduced by 377 t N yr−1 (39%) since 2000. The observed downward trend is supported by monitoring data from two wetlands restored in 2001 and 2004 in the River Odense catchment.

Customer comments

No comments were found for Successful reduction of diffuse nitrogen emissions at catchment scale: example from the pilot River Odense, Denmark. Be the first to comment!