Catchment modelling for quantification of Swedish nutrient transport to the sea and effects of measures

Modelling techniques provide a way to synthesize and quantify the contributions from various nutrient sources. A hydrological-based model (HBV-NP) has been applied at different scales to investigate geographical distributions of the leaching pattern and explore the effects of countermeasures. Nutrient load has been modelled for the whole of Sweden (about 450 000 km 2 ). Additionally, the model has been used to elaborate specific measure programmes to reach the Swedish nutrient goals for the river catchments Motala Stream (15 500 km 2 ) and Ronnea (1900 km 2 ), and for interactive modelling, based on a dialogue between various stakeholders and modellers at the local scale (350 km 2 ).