Toward Simple Modeling Practices in the Complex Canadian Prairie Watersheds

The prairie region in Canada has been characterized as a graveyard of hydrological models due to its challenging cold-regions processes and complex landscape with numerous land depressions that influence runoff pathways. Efforts were made at the small-basin scale to propose new algorithms and/or modify existing physically based hydrological models in order to achieve some semblance of a coherent mathematical runoff modeling system. To date, there has been very little research on modifying conceptual bucket-type models to include lateral pothole flow complexities for peak-flow estimation. In this study, the conceptual Hydrologiska Byråns Vattenbalansavdelning (HBV)-light model is modified to work in the prairies by incorporating a conceptual lateral-flow component to represent the pothole storage complexities. The modification of the HBV-light model resulted in a HYdrological model for Prairie Region (HYPR) that can be used for prairie streamflow simulation. The traditional HBV-light and HYPR conceptual models are tested on different pothole-dominated watersheds within the Qu’Appelle River Basin in Saskatchewan, Canada. The incorporation of a pothole storage-modeling component in HYPR results in a better streamflow simulation than that of HBV-light. Also, a new approach is proposed in this study to better identify the proper calibration period to arrive at a successful streamflow simulation. Although HYPR’s processes representation is simplified, the model shows potential for simulating the overall hydrograph and peak flows. HYPR shows strengths as a possible tool for operational and flood prediction purposes in the prairies, especially when data are limited.