Towards improved large scale hydrological modeling: applications to the Saskatchewan River Basin

Abstract:

The overall purpose of this research is to improve modeling capability, for large-scale hydrological models and land surface schemes. This aims to enhance understanding of the basin-scale modelling process, and advance representation of the flux exchange between the land surface and atmosphere for fully coupled atmosphere-land surface scheme modeling. The study is conducted on the Saskatchewan River Basin (SaskRB), which is a GEWEX Regional Hydroclimate Project and part of the Changing Cold Regions Network (CCRN). We applied and tested MESH (Modélisation Environmentale Communautaire – Surface and Hydrology), which is a Canadian hydrological modelling system based on the Canadian Land Surface Scheme (CLASS), utilizing climate and assimilated remotely sensed data with ground-based observations.

 Targets of research are to 1) apply high resolution multiple climate forcing to enhance the representation of the alpine region; 2) refine the land surface modeling framework process representation through incorporating the annual and seasonal dynamic behavior of prairie pothole region streamflow contributing area; 3) implement the water storage and water abstraction dimension into the MESH modeling system to capture regulated catchments within the basin; 4) increase the parameter identifiability by introducing spatio-temporal multi-calibration of point and state variables against ground-based observation and remotely sensed data (for instance comparisons of modeled water storage change and soil moisture against GRACE and SMAP satellite products); 5) regionalize well-identified parameters to ungauged catchments assuming that the enhanced parameter identification reduces model uncertainty and the uncertainty that propagate in the process of parameter regionalization to ungauged catchments. The paper presents analysis of baseline model performance and strategic research needs, and reviews the scope for high resolution atmospheric models to improve representation of precipitation in the Canadian Rocky Mountain headwaters.