FORURENS: Models and stable isotopes to quantify sources of nutrients transported by rivers to the sea: atmospheric deposition, land sources

This project will examine scenarios of changes in nutrient fluxes to the sea from atmospheric deposition and land-based sources. Integrated studies will be conducted at two river basins draining to the Norwegian Skagerrak coast; the eutrophic system Vansj ø/Hobøl and the oligotrophic system Tovdal River. The scenarios are linked to 'worst case, best case' possibilities with regard to changes in fluxes of atmospheric and land-based sources of nutrients in response to land-use change, management practices, a nd changes in emissions to the atmosphere. The project will draw extensively on results from earlier projects. New data will be collected on stable isotopes of N and C to quantify relative source strengths of nutrients. The data will be aggregated at the river basin scale by use of the models TEOTIL, INCA-P, INCA-N, HBV, MAGIC and MYLAKE. The project will be closely linked to ongoing national projects such as CLUE (NORKLIMA), and to marine projects on sugar kelp (Hav og kysten). This interdisciplinary pro ject has experts from all relevant sectors, will be of three years duration, has a budget of 2400 kNOK, and is a cooperative effort of NIVA, BIOFORSK, NVE and IFE in Norway and University of Reading, UK, and University of Virginia, USA.