Vermilion River Basin Study
The Vermilion River Basin (VRB) is located in the Parkland Natural Region of Alberta: covering an area of 7,860 km², it drains approximately 14% of the North Saskatchewan River Basin. This region is typical of the hydrology of the north-central Prairies. The VRB has been identified as one of most altered basins in the North Saskatchewan River Basin by the North Saskatchewan Watershed Alliance (NSWA). Of all the basin altering activities, wetland drainage is thought to be the most important in impacting watershed hydrology. The earliest drainage in the VRB was carried out in the Holden Drainage District in the upper basin starting in 1918. Subsequent drainage has occurred throughout the basin. Concerns relating to wetland drainage include enhanced flooding, deterioration in water quality, and impacts on the aquatic ecosystem. These concerns are of great interest to the NSWA that is responsible for completing a locally-developed and supported watershed plan that balances social, economic, and environmental needs of the watershed community. It is thought that application of the Cold Regions Hydrological Model Platform (CRHM) in the VRB can make contributions that will inform the development of this watershed plan.
CRHM is a physically based, distributed, modular, object-oriented model development platform. The component modules have been developed based on the results of 50 years of research by the University of Saskatchewan and Environment Canada in prairie, boreal, mountain and arctic environments. The system is very flexible and creates ‘purpose-built’ models for particular basins, environments and predictive needs.
In light of the importance of wetland in the Vermilion River Basin and the capability of CRHM, study objectives in two phases are to:
- Setup CRHM for the Vermillion River Basin and conduct preliminary tests using local meteorological data.
- Develop an improved wetland module that incorporates the dynamics of drained wetland complexes in the physically based, modular Prairie Hydrological Model of CRHM.
- Refine CRHM results using advances in the improved wetland module, additional parameter data and other adjustments as necessary.
- Demonstrate scenarios/sensitivity of landscape components such as wetlands and uplands to support planning decisions and make recommendations for land and watershed management.
- Apply CRHM results to fortify recommendations and support decision making during initial plan implementation.
Accordingly, the corresponding study approaches to the above objectives including:
- Existing data will be compiled on precipitation, hydrometeorology, wetland characteristics, stage and extent, drainage pattern and land cover in the Vermillion River Basin. Environment Canada and Alberta Environment weather station data will be examined and converted to CRHM observation files. Existing data sources of wetland characteristics and extent, drainage pattern and land cover will be reviewed, and compiled using GIS and other methods. The existing CRHM Prairie Hydrological Model formulation will be set up on the basin and test runs will be conducted and compared to streamflow hydrographs over multiple years.
- Improvements to the Prairie Hydrological Model formulation of CRHM will be made. Specifically the wetland module will be sequences of many wetlands of varying sizes, which will interact with each other to generate streamflow via the spill and fill runoff mechanism.
- The improved Prairie Hydrological Model of CRHM will be evaluated in the Vermillion River Basin through hydrological simulation and quantitative analysis of streamflow. Whilst calibration will be minimised and limited to non-physical aspects of the model, certain parameters will be optimised from these comparisons. For streamflow, both annual and peak flows are the parameters of interest.
- The improved Prairie Hydrological Model of CRHM will be used in sensitivity analysis of the effect of changing land cover and wetland drainage/restoration on streamflow for the Vermillion River. The model will simulate the hydrological processes and functions of prairie wetlands so that the hydrological impacts of drainage at downstream locations as well as the drainage effect on wetland state can be assessed. The sensitivity of wetland drainage/restoration and land cover change will be assessed progressively from the current state to a ‘highly altered state’ or from the current state to a historical state.
- This is a cooperative phase of the study in which the improved Prairie Hydrological Model of CRHM will be used to generate results on scenarios request to fortify recommendations, explore options and support decision making for the implementation of the Vermillion watershed plan.
Centre for Hydrology
University of Saskatchewan