Future climate change will exacerbate the pressures on scarce water resources and aquatic ecosystems, particularly in semi-arid western North American watersheds Planning to deal with problems of water quantity and quality requires holistic, predictive process-based knowledge of biophysical and biogeochemical systems and the future responses of these systems to climate and anthropogenic forcing. Physical parameters are likely to be altered under future hydrologic regimes, impact basic ecosystem functions. Forecasting the response of streambed composition, stream morphology, nutrient flux, and biotic community to specific changes in factors such as water and sediment supply is typically more narrative than quantitative. Specifically, it is important to understand how heterogeneity generated by sediment transport and deposition generates patterns of surface and subsurface water storage and exchange, stream metabolism, and cycling of ecologically important nutrients. There has been very limited work at the regional scale (multiple watershed) to couple hydrologic models with nutrient loading to develop quantitative estimates of interacting climate and land-use impacts on water quantity and quality.
Results/Conclusions
I will present a framework for predicting water quantity, quality, and timing changes resulting from the combined impacts of climate change and human decision-making and a mechanism for linking these results to organism and community level responses in fluvial systems.