2019–2020 Bushfire impacts on sediment and contaminant transport following rainfall in the Upper Murray River catchment

Abstract

This article is part of the special series "Ecological consequences of wildfires." The series documents the impacts of large-scale wildfires in many areas of the globe on biodiversity and ecosystem condition in both terrestrial and aquatic ecosystems, the capacity for systems to recover, and management practices needed to prevent such destruction in future.

Modelling the spatial extent of post‐fire sedimentation threat to estimate the impacts of fire on waterways and aquatic species

“…In addition, our model addresses how sediment threat in waterways is affected by interactions between time since fire, fire severity and soil and topographical properties (Cawson et al, 2016). More complex modelling approaches that focus on modifying the parameters of the RUSLE model to reflect the changing conditions of the post‐fire environment may be more powerful if current case studies can be extrapolated to larger scales (Biswas et al, 2021).…”

“…These highly visible soil, debris and ash sludges in waterways can cause high rates of immediate mortality and/or long‐term changes in waterway habitat. Sediment slugs arise because fires followed by rain can cause sediment influxes to waterways that are many times greater than pre‐fire (Biswas et al, 2021; Smith et al, 2011). To create a spatial model for post‐fire sedimentation threat for all rivers, streams and lakes (hereafter, waterways) within the study region, we built on the Revised Universal Soil Loss Equation (RUSLE; Renard et al, 1997; Renard & Freimund, 1994) by also considering fire extent and severity, and rainfall events likely to cause surface run‐off (and thus transport of sediment into waterways).…”

“…Note that these rankings do not predict the actual post‐fire sediment load in waterways and how sediment changes over time, nor do they consider the potential interactions between fire severity and the key soil and topographical variables. More complex modelling that considers these issues has been carried out at the sub‐catchment scale (Biswas et al, 2021), but is not yet possible at the scale of our study region. Our aim instead was to create a tool that could be used to quickly estimate the spatial extent of the threat of post‐fire sedimentation and use these data to inform rapid conservation interventions, such as fish rescues (Shelley et al, 2021), and conservation status assessments (Legge, Rumpff, et al, 2022).…”

Projecting Future Fire Regimes in a Semiarid Watershed of the Inland Northwestern United States: Interactions Among Climate Change, Vegetation Productivity, and Fuel Dynamics

“…However, in recent decades, large and high severity wildfires have become more common in locations that historically burned at low intensity (Deb et al., 2020; Williams et al., 2019; Xu et al., 2021). These fire regime shifts can transform ecosystem dynamics and structure, increase air and water pollution, cause flood and landslide hazards, and threaten human property and lives (Biswas et al., 2021; Bowman et al., 2009; Kemter et al., 2021; Smith et al., 2016). To mitigate future wildfire risk in the wildland urban interface, and to predict fire hazard across wildlands, forest managers need to better understand how climate change and wildfire interact at scales where management actions are implemented.…”

“…and threaten human property and lives (Biswas et al, 2021;Bowman et al, 2009;Kemter et al, 2021;Smith et al, 2016). To mitigate future wildfire risk in the wildland urban interface, and to predict fire hazard across wildlands, forest managers need to better understand how climate change and wildfire interact at scales where management actions are implemented.…”