Simulating hydrological impacts of climate and land use changes in the North Saskatchewan River Watershed, Alberta, using the ACRU agro-hydrological modelling system

Throughout the province of Alberta there is increasing demand for water due to population growth, and an increasing demand from agriculture and industry. In contrast, availability of future water resources is uncertain due to climate change, and future land use practices. The upper North Saskatchewan River (UNSR) watershed is situated south-west of Edmonton, with a watershed area of slightly over 28,000km2. This on-going research looks to model the UNSR watershed to help predict future stream flows in the UNSR, based on potential future climate change and land use changes within the watershed, by setting up the ACRU agro-hydrological modeling system (Schulze et al., 2004). Contour, stream, lake, and elevation point data were collected and processed to created a DEM of the study area. From the DEM, sub watersheds were created from flow gauging stations to later run the model and verify results on smaller portions of the watershed. The DEM was then used to interpolate solar radiation data, slope and aspect data for the study area. Soil, land cover, climate, and stream data were all collected and processed using ArcGIS to create hydrological response units (HRUs). Each HRU will be set up individually, so that a minimum daily time series of 30 years is available to simulate all elements of the hydrological cycle for each of the HRUs, including snow pack development and snow melt, actual evaporation, transpiration, soil moisture storage, storm flow and groundwater contributions. Once all the spatial parameters have been processed in the GIS and inputted into ACRU, the data will be simulated and outputs verified against streamflow observations from gauging stations within the UNSR watershed. This will be done to generate confidence in the various scenarios of hydrological impacts within the UNSR watershed. Verification analysis is important to determine if outputs from the model are consistent with the behaviour of the hydrological system. The verification analyses are based on comprehensive statistical analyses. Once the model has been determined to be within physically meaningful ranges, different climatic and land use scenarios will be integrated into the model to simulate the impacts of expected environmental changes, such as a decreased snow pack, or land use change, such as forest fires. Results of risk analyses of available water in rivers and reservoirs will provide critical information for water managers, particularly those in the energy industry. References: Schulze, R.E.; Lorentz, S.; Kienzle, S.W.; Perks, L. 2004: Modelling the impacts of land-use and climate change on hydrological responses in the mixed underdeveloped / developed Mgeni catchment, South Africa. System. BAHC-IGBP Publication, Springer, 17pp, with 14 Figures and 2 tables