The connections between climate, surface water, and groundwater means that assessing impacts of spatiotemporal variation in land-use/land-cover and climate on water resources requires an integrated approach. Physically based numerical models that include both surface water and groundwater processes can account for these dynamic connections. We will discuss the development of an integrated, regional-scale, groundwater-surface water model in HydroGeoSphere to assess historical effects (pre-1950) and future scenarios (post-2050) on land-use/land-cover and climate change on the hydrological regime in central Alberta. The ~6000 km2 study area is part of the lower headwaters of the Red Deer River and contains two large lakes popular for recreation. The area has multi-sector development pressures including agriculture, tourism, rural development, and unconventional hydrocarbon development which impact groundwater and surface water resources and their interaction. We will use the model to assess the cumulative impacts of land-use/land-cover and climate change on the hydrogeological regime, including changes in recharge, storage, groundwater flow directions, interactions with lakes and rivers, and evaluating lag times between changes at the surface and evidence for responses in the groundwater system. We will also investigate the potential long-term impacts of these alterations to groundwater quality, the availability of high-quality groundwater, and surface water quality. Understanding the connections between the hydrogeological regime and cumulative impacts of climate and land-use/land-cover changes at the surface can help inform water management decisions and help predict future risks to water security.
