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Climate change is driving the loss of alpine glaciers globally, yet investigations about the water quality of rivers stemming from them are few. Here we provide an overview assessment of a biogeochemical data set containing 200+ parameters that we collected between 2019 and 2021 from the headwaters of three such rivers (Sunwapta‐Athabasca, North Saskatchewan, and Bow) which originate from the glacierized eastern slopes of the Canadian Rocky Mountains. We used regional hydrometric data sets to accurately model discharge at our 14 sampling sites. We created a Local Meteoric Water Line (LMWL) using riverine water isotope signatures and compared it to collected regional rain, snow, and glacial ice signatures. Principal component analyses of river physicochemical measures revealed distance from glacier explained more data variability than other spatiotemporal factors (i.e., season, year, or river). Discharge, chemical concentrations, and watershed areas were then used to model site‐specific open water season yields for 25 parameters. Chemical yields followed what would generally be expected along river continuums from glacierized to montane altitudinal life zones, with landscape characteristics driving chemical sources and sinks. For instance, particulate chemical yields were generally highest near source glaciers with proglacial lakes acting as settling ponds, whereas most dissolved yields varied by parameter and site. As these headwaters continue to evolve with glacier mass loss, the data set and analyses presented here can be used as a contemporary baseline to mark future change against. Further, following this initial assessment of our data set, we encourage others to mine it for additional biogeochemical studies. Plain Language Summary: Alpine glaciers are vulnerable to climate change, with their numbers and sizes expected to decline dramatically within the current century. It is known that a decrease in glacier mass will have direct consequences on glacial meltwater quantity, but how this may impact the quality of receiving freshwaters is less understood. Our goal was to record a water quality data set of 200+ physical and chemical parameters for the headwaters of three major rivers draining glaciers on the eastern slopes of the Canadian Rocky Mountains. We first used statistics to model how fast the rivers were flowing at our 14 sampling locations over our 2‐year sampling period. We then looked at how and why water isotopes collected from river, rain, snow, and glacier ice samples differed. We discovered that distance downstream from the glacier explained more statistical variation in our physical and chemical measures than season, year, or river. Finally, at each of our sampling sites, we calculated chemical yields, or the amount of chemical constituent being exported downriver per unit watershed area, and found landscape features like lakes, outwash plains, and forests influence them. We ultimately hope that others use our comprehensive data set to investigate this changing region further. Key Points: We assessed a 200+ parameter data set collected from glacial river headwaters on the eastern slopes of the Canadian Rocky MountainsOur findings can act as a contemporary reference for future investigation of glacial headwaters in rapidly evolving alpine regionsThe possibilities for data exploration of our 260,000+ measure data set are numerous and we encourage others to mine it for new studies [ABSTRACT FROM AUTHOR]

Purpose: Multimodal effective particle size distributions (EPSDs) develop as flocculation and particle breakage occur dynamically in a fluid shear and such distributions have been previously reported in coastal and estuarine waters to understand flocculation processes. Here, we use time varying multimodal EPSDs and hydraulic parameters (discharge and bed shear stress) to assess freshwater flocculation in a gravel-bed river in southern Alberta, Canada. Methods: Instantaneous discharge, volume concentration (VC), and EPSD of suspended solids were measured during three high discharge events at four study sites in a 10 km reach of the Crowsnest River. The EPSD and VC of suspended solids (< 500 µm) were measured in the centroid of flow with a LISST-200x. Bed shear stress for measured discharge was obtained using a flow model, MOBED. Results: Multimodal EPSDs consisted of primary particles, flocculi, microflocs, and macroflocs. Shear dependent flocculation was consistently observed for all sites and events, due to low and high shear stress flocculation, particle breakage, and mobilization of tributary sub-catchment derived particles. Higher shear stress limited flocculation to smaller floc sizes, while lower bed shear stress conditions created higher volumes of macroflocs. Conclusion: Flocculation and particle breakage processes based on relationships between particle size and hydraulic properties presented herein have implications for advancing fine sediment transport models by a variable cohesion factor as a function of floc size class. [ABSTRACT FROM AUTHOR]

The complex mechanisms driving runoff dynamics in mountainous watersheds with thick glacial till and fractured bedrock are not well understood. We examined long‐ and short‐term precipitation‐runoff relationships and quantified subsurface storage in watersheds on the eastern slopes of Canada's Rocky Mountains to develop a conceptual understanding of runoff generation processes in this region. Fractured permeable bedrock (bedrock storage) and glacial till deposits (soil and till storage) collectively result in large dynamic storage (hydrologically active storage). The transition from multiyear dry to multiyear wet patterns increased specific discharge due to less bedrock storage opportunity but did not influence event‐scale rainfall‐runoff responses. Rather, event‐scale rainfall‐runoff responses were governed by snowmelt and soil and till storage capacity. While winter snowfall was an important predictor of annual runoff ratios, storage at the end of the previous fall also influenced runoff ratios. These complex subsurface dynamics and large storage capacities are important for understanding how mountainous watersheds with glacial till deposits may respond to disturbance or climate change. Key Points: Precipitation‐runoff relationships are influenced by variation in annual and seasonal storageWet and dry multiyear precipitation patterns did not influence event‐based rainfall‐runoff responsesThick glacial till and permeable bedrock have large storage capacities [ABSTRACT FROM AUTHOR]

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The Western Boreal Plain of North Central Alberta comprises a mosaic of wetlands and aspen ( Populus tremuloides) dominated uplands where precipitation (P) is normally exceeded by evapotranspiration (ET). As such these systems are highly susceptible to the climatic variability that may upset the balance between P and ET. Above canopy evapotranspiration (ETC) and understory evapotranspiration (ETB) were examined using the eddy covariance technique situated at 25.5 m (7.5 m above tree crown) and 4.0 m above the ground surface, respectively. During the peak period of the growing seasons (green periods), ETC averaged 3.08 mm d−1 and 3.45 mm d−1 in 2005 and 2006, respectively, while ETB averaged 1.56 mm d−1 and 1.95 mm d−1. Early in the growing season, ETB was equal to or greater than ETC once understory development had occurred. However, upon tree crown growth, ETB was lessened due to a reduction in available energy. ETB ranged from 42 to 56% of ETC over the remainder of the snow-free seasons. Vapour pressure deficit (VPD) and soil moisture (θ) displayed strong controls on both ETC and ETB. ETC responded to precipitation events as the developed tree crown intercepted and held available water which contributed to peak ETC following precipitation events >10 mm. While both ETC and ETB were shown to respond to VPD, soil moisture in the rooting zone is shown to be the strongest control regardless of atmospheric demand. Further, soil moisture and tension data suggest that rooting zone soil moisture is controlled by the redistribution of soil water by the aspen root system. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Consecutive multiple disturbances to northern peatlands can dramatically impact peat hydrophysical properties. We examine the impact of a double disturbance (drainage and wildfire) on the hydrophysical and moisture retention properties of peat, a key regulator of peatland ecohydrological resilience, and compare this with the impact to each individual disturbance (drainage and wildfire). The compound effect of drainage and wildfire resulted in a shift of the surface datum down the peat profile, revealing denser peat. Less-dense near-surface peats that regulate water-table position and near-surface moisture content, both favourable to Sphagnum recolonization, were lost. At a drained peatland that was then subject to wildfire, peat bulk density increased by 14.1%, von Post humification class increased by two categories and water retention increased by 15.6%, compared with an adjacent burned but undrained (single disturbance) portion of the fen. We discuss the key hydrophysical metrics of peatland vulnerability and outline how they are affected by the isolated impacts of drainage and wildfire, as well as their combined effects. We demonstrate that multiple peatland disturbances have likely led to an increase in hydrological limitations to Sphagnum recovery, which may impact peatland ecohydrological resilience. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the Canadian Western Boreal Plain (WBP), wetlands (ponds and peatlands) comprise up to 50% of the landscape and represent unique habitat where summer precipitation is often outpaced by evapotranspiration and hillslope groundwater position does not follow topography. In this sub-humid location, groundwater fluxes and stores in riparian peatlands influence pond water levels and root zone moisture sources for forested uplands. To accurately describe the transport and retention of water in peat, it is important to consider peat subsidence. This paper quantifies the amount and effect of seasonal subsidence in a riparian peatland in the Utikuma Lake region in north-central Alberta, Canada. Results demonstrate that the deep and poorly decomposed peat deposits are resistant to compression, and that thick (and persistent) ground frost hinders pore collapse (shrinkage) above the water table until late summer when the ground has thawed. Even then, subsidence is still limited to the top 50 cm and is not closely related to changes in peatland water table or pond water level. Thus the water balance of these ponds and riparian areas appears to be less sensitive to peat volume changes than it is to the persistence of a substantial frost layer well into the snow-free period. [ABSTRACT FROM AUTHOR]

The relative contributions to total actual evapotranspiration (AET) from pond and riparian areas in a pond-wetland complex in the Western Boreal Plain (WBP) of northern Alberta are measured using the Bowen ratio energy balance technique. Measurements show that a pond typical of the WBP evaporates at a rate more than twice that of the adjacent riparian peatland. Relating the actual to potential evapotranspiration over both surfaces yields Priestley-Taylor α, coefficients of 0.60 and I-II for the peatland and pond respectively. Further results demonstrate that the sheltering and turbulent influences of the adjacent forested areas must be considered in the processes governing the permanence of WBP ponds. That is, forestry practices may inadvertently enhance the evaporative losses from the ponds, over and above the controls exerted by the regional climate. [ABSTRACT FROM AUTHOR]

Examines the effects of cold temperatures on breakage of lodgepole pine and white spruce twigs. Use of a two-point bending test; Influence of temperature on crown friction; Dependence of shoot brittleness on the temperature.

Abstract unavailable [ABSTRACT FROM AUTHOR]