Water resources under climatic stress. An integrated assessment of impacts on water availability and water quality under changing climate and land use

Climate change is one of the major challenges of our time and adds considerable stress to the human society and environment. A change in climate will not only shift general weather patterns (e.g. increasing winter precipitation in Northern Europe and decreasing summer precipitation in Southern and Central Europe), but also might increase the recurrence of extreme weather events such as drought and heavy rainfall. These changes are likely to pose major threats on water resources over the next decades. Direct impacts may include rising temperatures that will affect biological processes (e.g. growth, activities) and chemi-cal (equilibriums and solubility) processes. Changing precipitation patterns e.g. alters nu-trient loads emitted from non-point sources as well as changing low flow conditions alter stream concentrations form point source pollutions. Indirectly, a changing climate impacts major water users such as agriculture and leads to adaptation with possible effects on wa-ter quality. Possible agricultural adaptation strategies include changes in land use intensity, cultivar, crop species, livestock numbers and irrigation regimes. Although there have been a number of studies on the effect of climate change on crop management and productivity, most of them do not consider the environmental implications of these adaptation strate-gies. As agriculture is not only a major user of water resources (rain water and irrigation), but also one of the main contributors to the pollution of surface and ground waters, land use changes and production intensities may severely affect the quantity and quality of wa-ter bodies. In consequence, modifications in land use induced by climate and socioeconom-ic changes might not only threaten the availability of water resources (e.g. as drinking wa-ter or irrigation water), but also influence the compliance with the good ecological and chemical status according to the EU Water Framework Directive. The objective of this project is to develop and apply an integrative and interdisciplinary methodology to address the following main research questions: - How do climate and socio-economic changes affect Austrian land use and management intensities, the induced nutrient losses and consequently the quality and quality of sur-face and groundwater water bodies? - What are the direct and indirect impacts of these changes on chemical and biological processes in surface water? - Which cost-effective agricultural adaptation measures can counteract the adverse direct and indirect impacts of climate change on agricultural production, water resources, and water quality in Austria? - How big are the associated impact uncertainties and how can they be communicated to stakeholders?