Montane seasonal and elevational precipitation gradients in the southern Rockies of Alberta, Canada
| dc.contributor.author | Barnes, Celeste | |
| dc.contributor.author | MacDonald, Ryan J. | |
| dc.contributor.author | Hopkinson, Chris | |
| dc.date.accessioned | 2025-05-12T22:46:07Z | |
| dc.date.available | 2025-05-12T22:46:07Z | |
| dc.date.issued | 2025 | |
| dc.description | Open access article. Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International license (CC BY-NC-NC 4.0) applies | |
| dc.description.abstract | Modelling precipitation inputs in mountainous terrain is challenging for water resource managers given sparse monitoring sites and complex physical hydroclimatic processes. Government of Alberta weather station uncorrected and bias-corrected precipitation datasets were used to examine elevational precipitation gradients (EPGs) and seasonality of EPGs for six South-Saskatchewan River headwater sites (alpine, sub-alpine, valley). January EPG from valley to alpine sites (730 m elevation difference) using uncorrected precipitation was 19 mm/100 m. Corrected EPG was approximately three times greater (61 mm/100 m). The valley received more precipitation than the alpine (inverse EPG) in late spring and summer. A seasonal signal was present whereby all sites demonstrated 50%–70% lower summertime precipitation relative to winter months, with the greatest seasonal variance at the alpine site. Winter watershed-level spatialized precipitation volume was compared to modelled snow water equivalent (SWE) associated with two late-winter airborne lidar surveys. Uncorrected volumes (2020: 64.0 × 106m3, 2021: 63.2 × 106m3) were slightly higher than modelled mean SWE (2020: 51.6 × 106m3, 2021: 44.2 × 106m3) whereas bias-corrected (2020: 120.5 × 106m3, 2021: 119.7 × 106m3) almost doubled the estimate. Corrected precipitation is assumed closer to the true value. Cumulative sublimation, evaporation and snowmelt losses result in ground-level snowpack yield that deviates from total atmospheric precipitation in an increasingly negative manner. The 2020/2021 simulations suggest wintertime atmospheric precipitation exceeds late-winter snowpack accumulation by up to 57% and 63%, respectively. A loss of 16 × 106m3 (7%) watershed SWE from the alpine zone was partially attributed to redistribution downslope to the treeline-ecotone. Physical snowpack losses from sublimation and melt, or modelling uncertainty due to precipitation correction and alpine snow-density uncertainties can also contribute to observed discrepancies between in situ SWE and cumulative precipitation. Ignoring bias-correction in headwater precipitation estimates can greatly impact headwater precipitation volume estimates and ignoring EPG seasonality is likely to result in under-estimated winter and over-estimated summer yields. | |
| dc.description.peer-review | Yes | |
| dc.identifier.citation | Barnes, C., MacDonald, R. J., & Hopkinson, C. (2025). Montane seasonal and elevational precipitation gradients in the southern Rockies of Alberta, Canada. Hydrological Processes, 39(1). https://doi.org/10.1002/hyp.70061 | |
| dc.identifier.uri | https://hdl.handle.net/10133/7029 | |
| dc.language.iso | en | |
| dc.publisher | Wiley | |
| dc.publisher.department | Department of Geography and Environment | |
| dc.publisher.faculty | Arts and Science | |
| dc.publisher.institution | University of Lethbridge | |
| dc.publisher.institution | MacDonald Hydrology Consultants Ltd. | |
| dc.publisher.url | https://doi.org/10.1002/hyp.70061 | |
| dc.subject | Canadian Rocky Mountain eastern slopes | |
| dc.subject | Elevational precipitation gradients | |
| dc.subject | Mountain precipitation | |
| dc.subject | Seasonality | |
| dc.subject | SWE | |
| dc.subject | Water resource management | |
| dc.subject.lcsh | Hydrologic models--Alberta | |
| dc.subject.lcsh | Water supply--Alberta | |
| dc.subject.lcsh | Water-supply--Management--Alberta | |
| dc.title | Montane seasonal and elevational precipitation gradients in the southern Rockies of Alberta, Canada | |
| dc.type | Article |