Assessing wildfire risk to municipal drinking water using paleoecology
department or school: Science, Irving K. Barber Faculty of (Okanagan)
department or school: Earth, Environmental and Geographic Sciences, Department of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Hebda, Nicholas J. R.
issued: 2022-10-27T16:47:10Z
issued: 2022
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Wildfire regimes are changing, with fires becoming more frequent and intense globally as climate change advances, putting natural capital such as surface water at risk. Wildfires can detrimentally impact surface water quality by burning vegetation and altering soils, leading to increased erosion and release of contaminants into waterways, including reservoirs. Here, a multi-proxy paleoecological investigation assesses the risk posed by wildfire to water supply in a municipal drinking water catchment serving 400,000 people in the Capital Regional District (CRD) on Vancouver Island, British Columbia, Canada. Sediment records from Sooke Lake Reservoir and adjacent Begbie Lake were analyzed for charcoal, magnetic susceptibility, geochemistry, pollen, and diatoms to quantitatively reconstruct the terrestrial and aquatic biogeochemical impacts of five past fire events at sub-decadal resolutions. Severe fires have burned in the Sooke watershed under differing climates, including modern conditions and past warmer, drier states. These past climates serve as analogues for anticipated future conditions. All five fires had statistically significant effects on terrestrial and aquatic systems in the study watershed across diverse physical, chemical, and biological fire-related proxy indicators. Magnetic susceptibility, sediment chemistry, and fossil diatom evidence reveal post-fire increases in soil erosion and water column turbidity. Sediment concentrations of potentially toxic elements, including barium, chromium, and lead, also increased after several fires. These fire-induced changes likely persisted for decades, in some cases perhaps more than a century. Overall, this study suggests that Sooke Lake Reservoir and Begbie Lake are vulnerable to post-fire effects which last for many years before pre-fire conditions return. Wildfires pose a significant threat to water quality and water supply security in the CRD. These insights into location-specific catchment fire characteristic…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/83072
note: ASSESSING WILDFIRE RISK TO MUNICIPAL DRINKING WATER USING PALEOECOLOGY by Nicholas J. R. Hebda B.Sc., University of Victoria, 2010 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE COLLEGE OF GRADUATE STUDIES (Earth and Environmental Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) October 2022 © Nicholas J. R. Hebda, 2022 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: ASSESSING WILDFIRE RISK TO MUNICIPAL DRINKING WATER USING PALEOECOLOGY submitted by Nicholas J. R. Hebda in partial fulfillment of the requirements of the degree of Doctor of Philosophy. Dr. Ian Walker, Irving K. Barber Faculty of Science Supervisor Dr. Kendrick Brown, Irving K. Barber Faculty of Science Co-Supervisor Dr. David Scott, Irving K. Barber Faculty of Science Supervisory Committee Member Dr. Adam Wei, Irving K. Barber Faculty of Science Supervisory Committee Member Dr. Robert Lalonde, Irving K. Barber Faculty of Science University Examiner Dr. Mitchell Power, College of Science, University of Utah External Examiner iii Abstract Wildfire regimes are changing, with fires becoming more frequent and intense globally as climate change advances, putting natural capital such as surface water at risk. Wildfires can detrimentally impact surface water quality by burning vegetation and altering soils, leading to increased erosion and release of contaminants into waterways, including reservoirs. Here, a multi-proxy paleoecological investigation assesses the risk posed by wildfire to water supply in a municipal drinking water catchment serving 400,000 people in the Capital Regional District (CRD) on Vancouver Island, British Columbia, Canada. Sediment records from Sooke Lake Reservoir and adjacent Begbie Lake were analyzed for charcoal, magnetic susceptibility, geochemistry, pollen, and diatoms to quantitatively reconstruct the terre…
has type: Thesis/Dissertation
date issued: 2022-11
is shown at: 10.14288/1.0421622
language: eng
degree discipline: Earth and Environmental Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Walker, Ian
contributor: Brown, Kendrick Jonathan, 1969-
type: Text
identifier URI: http://hdl.handle.net/2429/83072