Modelling nutrient pollution in the Danube River Basin : a comparative study of SWAT, MONERIS and GREEN models

The Water Framework Directive requires the development and implementation of river basin management plans for improving the ecological status of freshwater bodies throughout Europe. The scientific community supports this process by developing decision-support tools for identifying the principal sources of water pollution. Integrated Basin Models provide a transparent framework to assess the dominant processes affecting nutrient emissions pathways and retention. Models, however, are imperfect representations of the real world, and are conditioned by structural uncertainty, implicit in the description of biophysical processes and data uncertainty, implicit in the environmental data upon which the models were developed. Hence, decision makers must plan management actions on the basis of the best available, however still incomplete, knowledge. The comparison of independent assessments may offer insights that are useful for decision-making, e.g. for identifying knowledge gaps, identifying data uncertainties, consolidating investigation results, and increasing stakeholders' acceptance