Enhanced hydrologic connectivity and solute dynamics following wildfire and drought in a contaminated temperate peatland catchment
Author(s)
Type
Journal Article
Abstract
Intact peatlands provide hydrological ecosystem services, such as regulating water regimes and immobilizing pollutants within catchments. Climate change impacts including drought and wildfire may impair their functioning, potentially impacting ecosystem service delivery. Here we investigate stream water quality changes following the combined impacts of a summer drought and wildfire in a peat-dominated catchment in the UK during 2018. The study catchment stores legacy pollutants (i.e., metals) due to past industrial activity, thus making it particularly susceptible to pollutant release during wildfires. We quantified changes in water chemistry during five storm events over a 9-month period following the wildfire. Concentration-discharge (C-Q) relationships for nine solutes were analyzed to explore changes in activation and connectivity of solute source zones. Hysteresis and flushing indices of C-Q responses further described solute dynamics during storm events. We found that most nutrient and base cation concentrations in the stream discharge were highest in the immediate post-fire storm events and decreased during subsequent autumn and spring storms. Metal concentrations increased during autumn and spring storms, indicating delayed mobilization from within-peat or distal headwater sources. Our findings suggest that seasonal re-wetting and hydrologic connectivity following disturbance influenced solute source zone activation and transport in the study catchment. Water quality responses associated with wildfire and drought were primarily observed in the months following the wildfire, suggesting mobilization of pollutants peaks shortly after fire. Our results contribute to a critical understanding of the future of water quality risks in temperate peatland catchments subject to disturbances exacerbated by climate change.
Date Issued
2024-07
Date Acceptance
2024-06-16
Citation
Water Resources Research, 2024, 60 (7)
ISSN
0043-1397
Publisher
Wiley
Journal / Book Title
Water Resources Research
Volume
60
Issue
7
Copyright Statement
© 2024. The Authors.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023WR036412
Subjects
BLANKET PEAT
blanket peatland
concentration-discharge relationship
DISTRICT
Environmental Sciences
Environmental Sciences & Ecology
ERODED PEATLAND
FIRE SEVERITY
heavy metals
hysteresis
HYSTERESIS
legacy pollutants
Life Sciences & Biomedicine
Limnology
Marine & Freshwater Biology
METAL
Physical Sciences
RUNOFF GENERATION
Science & Technology
SOUTH PENNINES
SURFACE WATERS
Water Resources
WATER-QUALITY
Publication Status
Published
Article Number
e2023WR036412
Date Publish Online
2024-06-27