HR: 1340h
AN: H43A-0495    [Abstracts]
TI: Impacts of Climate Change on the Surface and Subsurface Hydrology of the Grand River Watershed
AU: * Colautti, D
EM: dcolautt@sciborg.uwaterloo.ca
AF: University of Waterloo, Department of Earth Sciences, 200 University Avenue West, Waterloo, Ont N2L 3G1 Canada
AU: Sudicky, E A
EM: sudicky@sciborg.uwaterloo.ca
AF: University of Waterloo, Department of Earth Sciences, 200 University Avenue West, Waterloo, Ont N2L 3G1 Canada
AU: Sykes, J F
EM: sykesj@uwaterloo.ca
AF: University of Waterloo, Department of Civil Engineering, 200 University Avenue West, Waterloo, Ont N2L 3G1 Canada
AB: The impact of global climate change on the quantity and quality of groundwater and surface water resources over the next century is gaining widespread attention, especially within hydrologically and ecologically sensitive basins. One such locale is the Grand River Basin (GRB), a 6800 km2 area in South-Central Ontario, Canada encompassing several major urban centers and providing about 10% of the drainage to Lake Erie. Approximately 82% of the water supply within the GRB is currently derived from groundwater, a resource that could be adversely impacted by climate change. To date, few high-resolution, physically-based flow models have been applied at the scale of the GRB that fully couple surface flow processes over the 2D land surface to variably-saturated 3D subsurface flow. Here, transient, 100-year duration simulations of the GRB driven by alternative climate change scenarios are presented using the fully-integrated HydroGeoSphere model developed at the University of Waterloo and Laval University. It is a three-dimensional, control-volume finite element model that solves the relevant nonlinear surface and subsurface flow equations simultaneously at each time step. Extensive hydrological, hydrogeological and land use data are available to characterize surface and subsurface hydraulic properties of the GRB. For example, data from approximately 60,000 water well records were used to construct the subsurface stratigraphy within the basin. Land use - land class maps coupled with spatial soil maps in an ArcView GIS framework were used to define the surface and shallow porous media properties that are necessary for the estimation of physically based temporally and spatially varying values of infiltration, evapotranspiration and recharge. The GIS database also facilitated the development of spatially varying surface roughness coefficients. Historical daily climate data for the 40 year period beginning in 1960 were used as the basis for assessing the impact of expected future climate change scenarios. In addition to presenting results that demonstrate the impacts of climate change on both the surface and subsurface flow regimes within the GRB, computational challenges associated with high-resolution simulations performed using a fully-integrated surface/subsurface flow model are discussed.
DE: 1805 Computational hydrology
DE: 1807 Climate impacts
DE: 1830 Groundwater/surface water interaction
DE: 1847 Modeling
SC: Hydrology [H]
MN: Fall Meeting 2005