Date of Award

8-17-2025

Document Type

Thesis

Abstract

Climate change is fundamentally altering Arctic hydrological systems, impacting water quality and posing challenges for communities dependent on these vulnerable sources. This study examines water quality trends across three distinct Arctic contexts: (1) Arctic glaciers, (2) the Yukon River Basin (YRB), encompassing a five-year dataset (2019-2023) of dissolved organic carbon (DOC), sulfate, and stable water isotopes (δ2H, δ18O, and d-excess) across varying permafrost regions and seasons, and (3) Shishmaref, Alaska, where a washeteria-based drinking water system is affected by environmental and seasonal changes triggered by climate change and coastal erosion. By addressing both regional hydrology and community-specific challenges, the study highlights the critical interplay between glacial melt dynamics, permafrost thaw, and water infrastructure vulnerabilities. This study focused on identifying significant spatial and temporal DOC variations, seasonal sulfate patterns, and stable isotope variability across permafrost regions. Additionally, seasonal differences in Shishmaref’s water quality were hypothesized to result from freeze-thaw processes, impacting heavy metals, sulfate, and nitrate levels. The findings reveal distinct biogeochemical and hydrological patterns: DOC fluxes peaked in late summer and fall, particularly in regions with sporadic and "Thick Thin" permafrost, driven by permafrost thaw and organic matter mobilization. Sulfate concentrations exhibited pronounced seasonal variability, with higher levels during peak thaw (June-August) influenced by sulfate-rich soils, glacial melt inputs, and runoff dynamics. Stable isotope enrichment in δ2H and δ18O and declining d-excess during summer reflected evaporation, altered precipitation sources, and shifting hydrological pathways In Shishmaref, seasonal monitoring revealed elevated heavy metal concentrations, such as zinc and copper, during winter due to infrastructure-related leaching and sediment mobilization under freezing conditions. Increased calcium and sodium concentrations during winter were linked to freeze-thaw-induced mineral dissolution and salt deposition. Conversely, DOC and SUVA values showed minimal seasonal variation, indicating consistent organic matter sources. These findings underscore the urgent need for localized water management strategies and long-term monitoring to mitigate the impacts of climate change on Arctic hydrology and community water security. By drawing parallels between Arctic glaciers and the YRB with specific challenges in Shishmaref water quality, this study offers a comprehensive understanding of Arctic water quality dynamics and their broader implications for adaptation and sustainability.

Handle

http://hdl.handle.net/11122/16255

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