|Title||A comparison and needs assessment of hydrological models used to simulate water balance in oil sands reclamation covers - Final Report|
|Year of Publication||2006|
|Authors||Seely, B., Welham C., & Elshorbagy A.|
|Publisher||Cumulative Environmental Management Association|
|Place Published||Fort McMurray, AB|
|Keywords||CEMA, hydrology, model, modeling, soil moisture, soil water|
The successful reclamation of Oil Sands mining areas requires the construction of soil covers that will provide a suitable substrate to support the growth and development of self-sufficient forest ecosystems. To be effective, soil covers must have the capacity to store soil water and to provide essential nutrients to support plant growth. Modelling tools are required to help navigate the complexity of issues that must be addressed in the development of such soil covers. The focus of this project was to evaluate the capability of existing models to simulate water balance in Oil Sands reclamation covers and to develop a strategy to meet the long-term needs with respect to hydrology and forest growth decision-support tools. The specific project objectives include the following: 1) evaluate the current status of two water balance modeling tools (SDWM & ForWaDy) in the Oil Sands, 2) assess the capabilities of each for practical applications in the Oil Sands reclamation areas, and 3) develop a plan to go forward with existing tools including opportunities for integration and the necessity to model the dynamic interactions between soil cover hydrology and forest growth. While similar in many respects (climate data requirements and basic structure) the two models differ in terms of their focal areas. ForWaDy is a vegetation-oriented model with a simulated partitioning of evapotranspiration among trees, competing vegetation and bare soil using an energy balance approach. The representation of soil water storage and flux in ForWaDy is relatively simple and based upon a tipping bucket approach. In contrast, the emphasis of SDWM is on soil physical processes, where the amount and rate of water movement is determined as a function of suction potential and other soil physical properties. The effect of vegetation on soil water storage and evapotranspiration rates is represented as a site-specific coefficient used in combination with air temperature and soil suction. An evaluation of performance in projecting trends in water storage and actual evapotranspiration (AET) for the different cover types applied in the SW30 Dump showed that the models performed similarly in terms of their accuracy relative to field measured data. In both cases models performed quite well in predicting patterns in soil moisture content. Model performance was generally better in representing peat layer moisture contents compared to till layer moisture contents. Potential reasons for deviations from till layer measurements are discussed.
CEMA Contract No. 2005-0030 RWG.
|Locational Keywords|| |
Alberta oil sands