As glaciers retreat in response to climate change, groundwater is expected to play an increasingly important role in sustaining proglacial streamflow. This study investigates groundwater contributions to the Boundary Peak glacier proglacial stream in the Canadian Rockies, within the Columbia Icefields, using hydrometric, isotopic, and geochemical methods to evaluate baseflow contributions and groundwater–surface water interactions in a glacierized watershed. This research is based on fieldwork conducted in 2023 and 2024, capturing seasonal variability in groundwater discharge._x000D_ _x000D_ Potential groundwater sources include subglacial flowpaths, adjacent rock glaciers, and deeper bedrock aquifers. Multiple tracer parameters—including stable isotopes, major ions, sulfate-silica relationships, radon, and tritium—are being analyzed alongside streamflow measurements to assess seasonal variability, groundwater residence times, and spatial trends in baseflow contributions. This research aims to clarify how groundwater sustains proglacial streamflow as glacier meltwater contributions decline, improving the understanding of long-term water availability and hydrologic resilience in alpine headwaters._x000D_ _x000D_ With continued glacier loss in western Canada, understanding groundwater’s role in maintaining late-season streamflow is essential for water security, hydrologic modeling, and watershed management. This study refines conceptual models of groundwater–glacier interactions, enhancing our ability to assess future water supply risks in mountain watersheds._x000D_ _x000D_ By evaluating groundwater’s role in buffering seasonal flow reductions, this research contributes to discussions on hydrologic variability, climate adaptation, and sustainable water resource planning. Findings will support evidence-based water management strategies, with implications for transboundary water governance and long-term hydrologic forecasting.
Mountain regions are highly vulnerable to the impact of climate change, with rising temperatures and shifting precipitation patterns, influencing the hydrological behavior of critical headwaters. River flow in these regions is sustained from rainfall and snow/ice melt, which follow various pathways, including overland flow, interflow, and groundwater, with distinct geochemical signatures. Changes in river geochemistry can thus serve as an indicator of flow pathways and residence times changes under the changing climate. This study investigates seasonal and long-term changes in river geochemistry and controlling factors over the periods of available data (1970-2022 and 2001-2022) in the Sheep River, which is an Eastern Slope River of the Canadian Rockies with a monthly average discharge of 7.5 m3/s. The river’s Ca-Mg-HCO₃ water type is consistent with the dominance of carbonate rocks in its headwaters. The C-Q relationships reflect varying degrees of groundwater dilution by a low solute end member. Over 1970–2022, a significant reduction in the C-Q slope (indicating increased dilution) was observed for Na, Cl, and K, while Ca, Mg, and SO₄ exhibited more chemostatic behavior. Trend analysis (1970–2022) revealed significant increases in major ions (i.e., Ca, Mg, SO4, Na, Cl, and K), especially during winter, spring freshet, and late summer, correlating with changes in climatic variables such as lagged precipitation and snowpack loss. The observed trends for major ions may suggest increased groundwater contributions under changing climatic conditions. The findings provide valuable insights for sustainable water resource management and developing climate adaptation strategies in alpine regions.
The connections between climate, surface water, and groundwater means that assessing impacts of spatiotemporal variation in land-use/land-cover and climate on water resources requires an integrated approach. Physically based numerical models that include both surface water and groundwater processes can account for these dynamic connections. We will discuss the development of an integrated, regional-scale, groundwater-surface water model in HydroGeoSphere to assess historical effects (pre-1950) and future scenarios (post-2050) on land-use/land-cover and climate change on the hydrological regime in central Alberta. The ~6000 km2 study area is part of the lower headwaters of the Red Deer River and contains two large lakes popular for recreation. The area has multi-sector development pressures including agriculture, tourism, rural development, and unconventional hydrocarbon development which impact groundwater and surface water resources and their interaction. We will use the model to assess the cumulative impacts of land-use/land-cover and climate change on the hydrogeological regime, including changes in recharge, storage, groundwater flow directions, interactions with lakes and rivers, and evaluating lag times between changes at the surface and evidence for responses in the groundwater system. We will also investigate the potential long-term impacts of these alterations to groundwater quality, the availability of high-quality groundwater, and surface water quality. Understanding the connections between the hydrogeological regime and cumulative impacts of climate and land-use/land-cover changes at the surface can help inform water management decisions and help predict future risks to water security.
Groundwater level variability plays a critical role in determining the spatial and temporal distribution of water resources, driven by interactions between climate, surface water, and subsurface processes. While subsurface processes are central to the quality of water influencing groundwater-dependent ecosystems, near-surface groundwater dynamics are increasingly recognized as an impediment to urban densification, where sub-grade construction intersects the water-table and future design requires perpetual de-watering. _x000D_ Decadal-scale climate variability, combined with historic water taking practices, present challenges when attempting to isolate seasonal variability. While there exists good data to support a static long-term average water-table map, what is unclear is the magnitude of variability one should expect year to year. Using advanced fitting techniques, both the long term and seasonal trends can be isolated._x000D_ We present a regional scale (~30,000 km2) interpolated water table map superimposed with seasonal variability that can be used (in part) by municipal planners in determining areas where development can likely occur without groundwater interference. Throughout the Greater Toronto Area, seasonal shallow groundwater variability averages about ±1 m from the static mean, but in places variability can reach ±5 m. Thus, the timing of any depth to groundwater estimation is not only locally dependent, but seasonally dependent._x000D_ Seasonal trends can be visually categorized into four main distributions, each peaking roughly by season (spring, summer, fall, winter). A challenge for future work would be to isolate longer term trends from climate influences and to isolate pumping influences.
