Modelling Cold Region Hydrology in an Agricultural Catchment in Southern Quebec, Canada
Abstract
Cold regions hydrology is largely governed by a number of unique processes related to snow and frozen ground, and the multiple interactions among these processes can result in complex and variable hydrological responses. There is thus a need to better understand and represent cold region hydrological processes within hydrological models in order to improve model assessments of potential climate change impacts on catchment hydrology. In this study, a physically-based hydrological model has been developed using the Cold Regions Hydrological Model (CRHM) for the l'Acadie River catchment in southern Quebec, Canada. Almost 75% of the catchment is occupied by agricultural fields, being representative of the intensive farming landscape of the southern St-Lawrence lowlands, while the remaining fraction is mostly forested. CRHM was parameterized to model the major hydrological processes thought to be important in the catchment, such as the redistribution of snow by wind, sublimation, frozen soil infiltration, snowmelt and runoff generation over a 20-year period. Simulated snow water equivalent (SWE) at the mixed forest hydrological response unit (HRU) was evaluated against the 20-year snow survey record from the Hemmingford Station located within a mixed forest landscape in the same region, while simulated streamflow was compared against streamflow records at the basin outlet. Preliminary results indicate that there is an adequate match between the simulated and observed SWE at the point scale. The simulated SWE varied among the different landscape units in the catchment, which is mostly due to snow redistribution by wind in response to changes in vegetation and topography. Snow is predominantly transported from agricultural fields and deposited in drainage canals and forest patches. Graphical comparison of modelled and measured streamflow indicated that the model tends to overestimate flood peaks while underestimating low flows. This is mostly attributed to the existence of the tile drainage system in the catchment, which is not explicitly represented in CRHM. Our next step is to improve the drainage representation in the model to account for the impacts of the tiles on the river hydrograph.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C43C1793A
- Keywords:
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- 0702 Permafrost;
- CRYOSPHEREDE: 0736 Snow;
- CRYOSPHEREDE: 0738 Ice;
- CRYOSPHEREDE: 1847 Modeling;
- HYDROLOGY