Effect of changing anthropogenic and climate conditions on BOD loading and in-stream water quality in Europe

Catchment scale modelling of water and solute transport and transformations is a widely used technique to study pollution pathways and effects of natural changes, policies and mitigation measures. There are, however, only a few examples of global water quality modelling. This paper provides a description of the new continental-scale water quality model WorldQual and the analysis of model simulations under changed climate and anthropogenic conditions with respect to changes in diffuse and point loading as well as surface water quality. Biological Oxygen Demand (BOD) is used as an indicator of the level of organic pollution and its oxygen-depleting potential, and for the overall health of aquatic ecosystems. The first application of WorldQual is to river systems of Europe. The model itself is being developed as part of the EU-funded SCENES Project which has the principal goal of developing new scenarios of the future of freshwater resources in Europe. Using WorldQual the influence of climate and anthropogenic changes on European water resources can be compared. The results indicate that changes in loading and in-stream concentrations following socio-economic changes and seem to override the effect of climate change.