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Influence of wildfire on the hydrology and runoff chemistry
Caren
J
Ackley, Wilfrid Laurier University, ackl2230@mylaurier.ca
(Presenter)
Wildfire trends throughout the arctic and subarctic show increasing fire frequency, size and severity. Occurrence of wildfire in the zone of discontinuous permafrost can impact the health and stability of boreal peatland ecosystems. Disturbance of the vegetative groundcover and tree canopy influence critical hydrological processes in this region that can lead to ecological changes. As snowmelt provides a significant source of freshwater in northern regions, changing fire regimes coupled with climate warming urgently call for an improved understanding of the impacts of wildfires on water resources. Here, we examine a tree-covered permafrost plateau at Scotty Creek in the Northwest Territories, Canada, where roughly half of the plateau was affected by a localized burn in July 2014. This study provides key insights into both the hydrological and geochemical impacts of wildfires. Water samples and field measurements were collected between April and August 2016 within study plots located in adjacent burned and unburned areas. These measurements were complimented by laboratory analysis of peat cores to examine the impacts of fire on physical, hydraulic and solute transport properties of soils within the plots. Increased SWE and melt rate in the burned area lead to a greater volume of runoff and earlier time to snow-free. Greater depth of seasonal thaw under the burn indicates permafrost degradation and flow path alteration. The concomitant assessment of changes in peat physical and hydraulic properties offer new insight into the mechanisms governing the partitioning of water between runoff and storage, and water quality changes that result from wildfire. Associated Project(s): Poster Location ID: 16 Session Assigned: Permafrost and Hydrology
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