Wildfire Rates of Spread in Grasslands under Critical Burning Conditions

Abstract

An analysis of a dataset (n = 58) of high-intensity wildfire observations in cured grasslands from southern Australia revealed a simple relationship suitable for quickly obtaining a first approximation of a fire’s spread rate under low dead fuel moisture contents and strong wind speeds. It was found that the forward rate of fire spread is approximately 20% of the average 10-m open wind speed. The data on rate of fire spread and 10 m open wind speed ranged from 1.6 to 17 and 20 to 62 km h−1, respectively. The validity of the resulting rule of thumb was examined across a spectrum of burning conditions and its performance was contrasted against that of established empirical-based fire spread models for three different grassland fuel conditions currently used operationally in Australia. The 20% rule of thumb for grassfires produced error statistics comparable to that of the fire spread rate model for grazed or cut grass fuel conditions as recommended for general use during the summer fire season in southern Australia.

Mapping South Florida Daily Fire Risk for Decision Support Using Fuel Type, Water Levels, and Burn History

“…Numerous factors contribute to fire risk and, ultimately, how fires ignite and spread [58]. Rather than attempting to predict fire occurrence, the FireHydro model focuses on understanding, if an ignition were to occur, whether the water level conditions are right for fire spread, and if so, to what spatial extent might the fire spread before hitting wetted fire breaks.…”

Assessing cross-boundary wildfire hazard, transmission, and exposure to communities in the Italy-France Maritime cooperation area

“…The study area was divided into 1,000-ha hexcells (n = 8,050). Salis et al 10.3389/ffgc.2023.1241378 Frontiers in Forests and Global Change 14 frontiersin.org herbaceous areas are characterized by the presence of fine-sized fuel particles (with varying loads depending on the level of management and grazing) which generally exhibits high surface area-to-volume ratios and are fully or nearly cured during the wildfire season: in combination with strong winds and low fuel moisture, herbaceous fuels can sustain the establishment of high wildfire spread and acceleration rates and the expansion potential of the fire fronts toward neighboring forests, shrublands and anthropic areas (Cheney et al, 1993;Cheney and Gould, 1995;Cruz et al, 2022). In this regard, the presence of agriculture and pastoral farms must be recognized as key factor for land management and fire risk reduction purposes, as it can limit continuity and load of flammable fuels (Catry et al, 2010;Aquilué et al, 2020;Colantoni et al, 2020;Spadoni et al, 2023).…”

Will fire-smart landscape management effectively buffer the effects of future climate changes and long-term land abandonment on fire regimes?

“…For example, in FFS, management measures focused on treating fuels in forest and shrubland, but not in grassland, which remained with high fuel loads. Thus, when cured grass fuels burned, particularly during summer and early fall, they were able to sustain res that spread fast (Cruz et al 2022b) and burn at moderate to high intensities (Alexander and Cruz 2018); in the SPFS strategy, despite grass fuels being managed, this measure did not prevent res, which spread fast in cured ne fuels, from reaching other landscape areas and burn into unmanaged shrublands or forests.…”