Regional Climate Projections for the Great Lakes Region with Application to Integrated Surface and Groundwater Modeling

In this presentation the impact of climate change on water resources in the Great Lakes region of North America will be discussed. Most current approaches do not consider the effects of the Great Lakes nor the interaction between groundwater and surface water in a physically consistent way.
Here we present climate projections for the Great Lakes region that are based on a high resolution regional climate model (WRF at 10km resolution), which has been coupled to a column lake model (FLake). These climate projections are then applied as boundary forcing to the fully-integrated hydrological model Hydrogeosphere (HGS) in order to assess the impact on surface water and groundwater resources in a major watershed in southern Ontario (the Grand River).
The simulation results suggest that an increase in winter precipitation can be expected, while large uncertainties exist in summer precipitation changes, which are associated with the convective parameterization. It is furthermore found that the hydrological response in both surface water and groundwater is dominated by the precipitation change in summer, and this effect is mediated by the subsurface. Changes in precipitation extremes, soil moisture and groundwater recharge will also be discussed.