Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock
<p>Permeable sedimentary bedrock overlain by glacial till leads to large storage capacities and complex subsurface flow pathways in the Canadian Rocky Mountain region. While some inferences on the storage and release of water can be drawn from conceptualizations of runoff generation (e.g., run...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-01-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://hess.copernicus.org/articles/25/237/2021/hess-25-237-2021.pdf |
| _version_ | 1819051686290784256 |
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| author | S. A. Spencer A. E. Anderson A. E. Anderson U. Silins A. L. Collins |
| author_facet | S. A. Spencer A. E. Anderson A. E. Anderson U. Silins A. L. Collins |
| author_sort | S. A. Spencer |
| collection | DOAJ |
| description | <p>Permeable sedimentary bedrock overlain by glacial till leads to large storage capacities and complex subsurface flow pathways in the Canadian Rocky Mountain region. While some inferences on the storage and release of water can be drawn from conceptualizations of runoff generation (e.g., runoff thresholds and hydrologic connectivity) in physically similar
watersheds, relatively little research has been conducted in snow-dominated
watersheds with multilayered permeable substrates that are characteristic
of the Canadian Rocky Mountains. Stream water and source water (rain,
snowmelt, soil water, hillslope groundwater, till groundwater, and bedrock
groundwater) were sampled in four sub-watersheds (Star West Lower, Star West Upper, Star East Lower, and Star East Upper) in Star Creek, SW Alberta, to characterize the spatial and temporal variation in source water contributions to streamflow in upper and lower reaches of this watershed. Principal component analysis was used to determine the relative dominance and timing of source water contributions to streamflow over the 2014 and 2015 hydrologic seasons. An initial displacement of water stored in the hillslope over winter (reacted water rather than unreacted snowmelt and rainfall) occurred at the onset of snowmelt before stream discharge responded significantly. This was followed by a dilution effect as snowmelt saturated the landscape, recharged groundwater, and connected the hillslopes to the stream. Fall baseflows were dominated by either riparian water or hillslope groundwater in Star West. Conversely, in Star East, the composition of stream water was similar to hillslope water in August but plotted outside the boundary of the measured sources in September and October. The chemical composition of groundwater seeps followed the same temporal trend as stream water, but the consistently cold temperatures of the seeps suggested deep groundwater was likely the source of this late fall streamflow. Temperature and chemical signatures of groundwater seeps also suggest highly complex subsurface flow pathways. The insights gained from this research help improve our understanding of the processes by which water is stored and released from watersheds with multilayered subsurface
structures.</p> |
| first_indexed | 2024-12-21T12:07:53Z |
| format | Article |
| id | doaj.art-183e921b34614311b9980c61ed0d137b |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-12-21T12:07:53Z |
| publishDate | 2021-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-183e921b34614311b9980c61ed0d137b2022-12-21T19:04:39ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382021-01-012523725510.5194/hess-25-237-2021Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrockS. A. Spencer0A. E. Anderson1A. E. Anderson2U. Silins3A. L. Collins4Department of Renewable Resources, University of Alberta, Edmonton, T6G 2G7, CanadaDepartment of Renewable Resources, University of Alberta, Edmonton, T6G 2G7, CanadaAlberta Agriculture and Forestry, Government of Alberta, Edmonton, T5K 1E4, CanadaDepartment of Renewable Resources, University of Alberta, Edmonton, T6G 2G7, CanadaSustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom<p>Permeable sedimentary bedrock overlain by glacial till leads to large storage capacities and complex subsurface flow pathways in the Canadian Rocky Mountain region. While some inferences on the storage and release of water can be drawn from conceptualizations of runoff generation (e.g., runoff thresholds and hydrologic connectivity) in physically similar watersheds, relatively little research has been conducted in snow-dominated watersheds with multilayered permeable substrates that are characteristic of the Canadian Rocky Mountains. Stream water and source water (rain, snowmelt, soil water, hillslope groundwater, till groundwater, and bedrock groundwater) were sampled in four sub-watersheds (Star West Lower, Star West Upper, Star East Lower, and Star East Upper) in Star Creek, SW Alberta, to characterize the spatial and temporal variation in source water contributions to streamflow in upper and lower reaches of this watershed. Principal component analysis was used to determine the relative dominance and timing of source water contributions to streamflow over the 2014 and 2015 hydrologic seasons. An initial displacement of water stored in the hillslope over winter (reacted water rather than unreacted snowmelt and rainfall) occurred at the onset of snowmelt before stream discharge responded significantly. This was followed by a dilution effect as snowmelt saturated the landscape, recharged groundwater, and connected the hillslopes to the stream. Fall baseflows were dominated by either riparian water or hillslope groundwater in Star West. Conversely, in Star East, the composition of stream water was similar to hillslope water in August but plotted outside the boundary of the measured sources in September and October. The chemical composition of groundwater seeps followed the same temporal trend as stream water, but the consistently cold temperatures of the seeps suggested deep groundwater was likely the source of this late fall streamflow. Temperature and chemical signatures of groundwater seeps also suggest highly complex subsurface flow pathways. The insights gained from this research help improve our understanding of the processes by which water is stored and released from watersheds with multilayered subsurface structures.</p>https://hess.copernicus.org/articles/25/237/2021/hess-25-237-2021.pdf |
| spellingShingle | S. A. Spencer A. E. Anderson A. E. Anderson U. Silins A. L. Collins Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock Hydrology and Earth System Sciences |
| title | Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| title_full | Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| title_fullStr | Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| title_full_unstemmed | Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| title_short | Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| title_sort | hillslope and groundwater contributions to streamflow in a rocky mountain watershed underlain by glacial till and fractured sedimentary bedrock |
| url | https://hess.copernicus.org/articles/25/237/2021/hess-25-237-2021.pdf |
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