Changes in land use and climate are both likely to adversely affect water cycle dynamics, however the potential impact of these changes are rarely quantified in regional watersheds. The PI's propose to explore complex climate-land-water interactions at scales that matter using an integrated modeling approach. Their proposed research will provide insight into the impacts of climate and land use changes separately, and then synergistically, on the spatial and temporal variation of water fluxes throughout regional Great Lakes watersheds. The models will also provide a framework to study the complex processes that control the interactions between surface water and groundwater at a watershed scale. High-resolution stream flow measurements and land use estimates will constrain process-based flow models. Pilot models of two experimental watersheds that drain into the Great Lakes will be refined to predict spatial and temporal dynamics of the water cycle fluxes. The proposed work has high intellectual merit because few studies have: (1) adequately addressed the interaction of climate and land use on water dynamics, (2) fully integrated three-dimensional groundwater and surface water flow models, (3) applied high-resolution stream flow data in a process model framework to estimate recharge rates for different land covers, and (4) developed mechanistic models of land-climate-hydrology interaction at the experimental watershed scale. The proposed work will have significant broader impacts. First, the results will help explain complex relationships between climate, land use and the water cycle at scales where decisions are commonly made. Second, scenarios of land use and climate change will be explored to provide information to local, state, regional and federal agencies. Third, the proposed education activities will provide students with a broad understanding of important climate-land-water interactions through a multidisciplinary environment. Finally, community stakeholders will be provided with information on how their actions impact water cycle dynamics.
