Modelling the regional sensitivity of snowmelt, soil moisture, and streamflow generation to climate over the Canadian Prairies using a basin classification approach
<p>This study evaluated the effects of climate perturbations on snowmelt, soil moisture, and streamflow generation in small Canadian Prairies basins using a modelling approach based on classification of basin biophysical characteristics. Seven basin classes that encompass the entirety of the P...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-10-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://hess.copernicus.org/articles/27/3525/2023/hess-27-3525-2023.pdf |
| Summary: | <p>This study evaluated the effects of climate perturbations on snowmelt, soil
moisture, and streamflow generation in small Canadian Prairies basins using a modelling approach based on classification of basin biophysical characteristics. Seven basin classes that encompass the entirety of the
Prairies Ecozone in Canada were determined by cluster analysis of these
characteristics. Individual semi-distributed virtual basin (VB) models
representing these classes were parameterized in the Cold Regions
Hydrological Model (CRHM) platform, which includes modules for snowmelt and
sublimation, soil freezing and thawing, actual evapotranspiration (ET), soil moisture dynamics, groundwater recharge, and depressional storage dynamics including fill and spill runoff generation and variable connected areas. Precipitation (<span class="inline-formula"><i>P</i></span>) and temperature (<span class="inline-formula"><i>T</i></span>) perturbation scenarios covering the range of climate model predictions for the 21st century were used to evaluate climate sensitivity of hydrological processes in individual land cover and basin types across the Prairies Ecozone. Results indicated that snow accumulation in wetlands had a greater sensitivity to <span class="inline-formula"><i>P</i></span> and <span class="inline-formula"><i>T</i></span> than that in croplands and grasslands in all basin types. Wetland soil moisture was also more sensitive to <span class="inline-formula"><i>T</i></span> than the cropland and grassland soil moisture. Jointly influenced by land cover distribution and local climate, basin-average snow accumulation was more sensitive to <span class="inline-formula"><i>T</i></span> in the drier and grassland-characterized basins than in the wetter basins dominated by cropland, whilst basin-average soil moisture was most sensitive to <span class="inline-formula"><i>T</i></span> and <span class="inline-formula"><i>P</i></span> perturbations in basins typified by pothole depressions and broad river valleys. Annual streamflow had the greatest sensitivities to <span class="inline-formula"><i>T</i></span> and <span class="inline-formula"><i>P</i></span> in the dry and poorly connected Interior Grasslands (See Fig. 1) basins but the smallest in the wet and well-connected Southern Manitoba basins. The ability of <span class="inline-formula"><i>P</i></span> to compensate for warming-induced reductions in snow accumulation and streamflow was much higher in the wetter and cropland-dominated basins than in the drier and grassland-characterized basins, whilst decreases in cropland soil moisture induced by the maximum expected warming of 6 <span class="inline-formula"><sup>∘</sup></span>C could be fully offset by a <span class="inline-formula"><i>P</i></span> increase of 11 % in all basins. These results can be used to (1) identify locations which had the largest hydrological sensitivities to changing climate and (2) diagnose underlying processes responsible for hydrological responses to expected climate change. Variations of hydrological sensitivity in land cover and basin types suggest that different water management and adaptation methods are needed to address enhanced water stress due to expected climate change in different regions of the Prairies Ecozone.</p> |
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| ISSN: | 1027-5606 1607-7938 |