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Fire effects on geomorphic processes

May 30, 2024

Fire-induced geomorphic changes, such as enhanced erosion and debris-flow activity, are expected to increase with climate change owing to increases in fire activity and rainfall intensification. In this Review, we summarize how landscape attributes, rainfall and burn severity influence post-fire geomorphic responses over a range of temporal and spatial scales. Sub-hourly rainfall intensity and burn severity control the magnitude of many post-fire geomorphic process rates through their influence on ground cover and rainfall-runoff partitioning. Post-fire debris flows (PFDFs) make a substantial contribution to the post-fire sediment cascade, transporting sediment from hillslopes to channels, adjacent floodplains and alluvial fans. By the late twenty-first century, PFDF activity is estimated to increase in 68% of areas in which PFDFs have occurred in the past and decrease in only 2% of locations. Once altered by fire, geomorphic state variables — such as infiltration capacity, canopy cover, ground cover and sediment availability — can recover to their pre-fire value or be shifted to a new value. Improved understanding of the factors that influence these post-fire trajectories could support targeted management and intervention strategies. Additionally, monitoring that extends beyond the first 1–3 years after fire and deeper integration of ecohydrological processes into geomorphic models are needed to improve forecasts of post-fire geomorphic responses.

Publication Year 2024
Title Fire effects on geomorphic processes
DOI 10.1038/s43017-024-00557-7
Authors Luke McGuire, Brian A. Ebel, Francis K. Rengers, Diana Vieira, Petter Nyman
Publication Type Article
Publication Subtype Journal Article
Series Title Nature Reviews Earth and Environment
Index ID 70255574
Record Source USGS Publications Warehouse
USGS Organization Geologic Hazards Science Center; WMA - Earth System Processes Division