The Impact of Thawing Permafrost on Arctic Catchments:Arctic Rivers in a Changing Landscape
The Arctic is warming at an unprecedented rate. Warming causes the thawing of the permafrost, which affects how the catchments store and release water. The relationship between discharge and groundwater (storage) is complicated and intertwined with many factors that are also influenced by changing h...
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| Format: | Book |
| Language: | English |
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2024
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| Online Access: | https://research.vu.nl/en/publications/1e503570-0d66-4349-b231-d41e08269cf2 https://doi.org/10.5463/thesis.693 https://hdl.handle.net/1871.1/1e503570-0d66-4349-b231-d41e08269cf2 https://research.vu.nl/ws/files/349246519/phdtemplate%20-%2066c4802712c2a.pdf https://research.vu.nl/ws/files/349246521/disscover%20-%2066c4804eb7031.pdf https://research.vu.nl/ws/files/349246523/title%20page%20-%2066338611326e5.pdf |
| Summary: | The Arctic is warming at an unprecedented rate. Warming causes the thawing of the permafrost, which affects how the catchments store and release water. The relationship between discharge and groundwater (storage) is complicated and intertwined with many factors that are also influenced by changing hydrologic behaviors. This relationship between discharge and groundwater can be examined with recession curve slope analysis. The changes observed in an evolving recession curve slope represent how groundwater flows within a catchment as the permafrost thaws. As the frozen soils thaw, flow paths open for increased hydrological connectivity and groundwater flow. This increase in connectivity allows for the increase of non-linearity of the storage-discharge relationship within a catchment. In this dissertation, the analysis of the recession curve is used to identify the impact of permafrost across different catchments. I present and expand on the trends and spatio-temporal differences between catchments in Sweden. I use a mechanistic modeling approach to demonstrate the potential changes that a thawing catchment undergoes. Finally, I explored the compounding impacts of permafrost thaw throughout nested catchments in Alaska (US). My results show that, throughout recent decades, a majority of catchments have shown an increase in the non-linearity of the discharge groundwater relationship. There is also a strong indication that the changes are seasonally biased, with spring having more linear responses than summer in Swedish catchments. Modeling potential changes in a catchment also presented reasonable explanations for increases in the slope of the recession curve, such as changes in the parameters of the active layer such as shallow surface permeability, shallow surface water retention, and subsurface water retention as well as catchment attributes such as subsurface flow length. It was also determined that there are characteristics of the catchment that can influence the influence of permafrost on the discharge of the ... |
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