Over the next decades, environmental and societal changes are expected to affect many drivers of river water quality and the ecological status of running waters may be strongly impacted. To deal with these changes, a decision support framework is needed that enables us to manage river water quality in a consistent and comprehensive way. The goal of this project was to develop a prototype of such a framework, to test it in selected case studies, and to assess how water quality may be influenced by future climate and societal changes.
Four socio-economic scenarios and eight management alternatives have been designed and analysed for two medium-sized catchments in the Swiss Plateau (Gürbe, Mönchaltorfer Aa). The results clearly suggest that future water quality and the ecological status are predominantly determined by human activities in each catchment as reflected in the socio-economic scenarios and the management alternatives. Climate change has generally a much weaker influence except for water temperature
For management, the results imply that tackling today’s problems will also alleviate most of the foreseen problems in the future – at least if we limit the time horizon to the middle of the 21st century. The effects of the warming climate on maximum stream temperature can be compensated by restoring the riparian vegetation, but this does not prevent the increase of average water temperatures.