Climate Change and Ground Water

This article summarizes the theory of climate change and the relationship of climate-change forcing to hydrologic and aquifer processes. It focuses on regional aquifer systems and on the methods to link large-scale climate-change processes to ground-water recharge and to simulate ground-water flow and solute transport in a warmer, 2xCO2 climate. The article reviews methods currently available to generate climate-change forcing and to simulate regional aquifer systems under ensuing hydrologic conditions. In addition, it outlines the development of a methodology to quantify the effects of climate change and of changes in ground-water use by population growth on hydrologic response. An example illustrates a specific procedure and our current capabilities and limitations to assess the potential impacts of a warming climate and population growth on regional-scale aquifer systems. The results indicate that aquifer exploitation strategies must take into account climatic variability and climate-change patterns. During protracted drought, the competition between human and ecological water uses is sharply accentuated. Changes in ground-water use may affect aquifer response more profoundly than climate change associated with modern global warming.