Assessing the effects of alternative fuel treatments to reduce wildfire exposure

Abstract

Effective landscape-scale fuel management strategies are essential for reducing wildfire risk in Mediterranean fire-prone areas. In this study, the minimum travel time (MTT) fire-spread algorithm as implemented in FlamMap was applied to assess the potential of alternative fuel treatments for lowering wildfire losses in a 5,740-ha study area in eastern Sardinia, Italy. Twenty-seven wildfires at 10-m resolution were simulated considering three wind speeds (15, 18, and 21 km h−1) to compare fuel treatments: no treatment (NT), irrigated agroforestry areas with shrub clearing (T1), prescribed fire in eucalyptus stands (T2), and irrigated grasslands (T3). The simulations replicated a recent large wildfire that occurred in the study area (Orrì wildfire, 2019) and considered the weather and fuel moisture conditions associated with this event. The average wildfire exposure outputs (burned area, probability of burning, conditional flame length, potential crown fire occurrence, and surfaces withflame lengths above 2.5 m) decreased after fuel treatments, compared to no treatment. T1 was the most effective strategy in mitigating wildfire hazards and provided the most significant performance for several wildfire exposure indicators. Treating only 0.5% of the study area (~ 30 ha) resulted in a decrease in all wildfire exposure metrics to ~ 10% within the study area. In addition, the total surface characterized by high flame length (average > 2.5 m) was the lowest in the T1 treatment. This study can help land and fire managers optimize fuel treatment opportunities and wildfire risk mitigation strategies in Mediterranean areas.

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

“…The wildfire modeling and exposure results from this study can guide the coordinated design of landscape fuel treatment projects across the IFM area. While our previous management-oriented works were limited to some study areas in Sardinia (Salis et al, 2016(Salis et al, , 2018Jahdi et al, 2023), we now have the required baseline information to extend the analysis to the entire cooperation area. For example, this expanded scope could facilitate the development of fuel reduction projects in high-priority areas, designed to protect communities in rural or forest areas where a declining population is leading to rapid fuel increase and pasture encroachment (Schuh et al, 2020).…”

A Planning Model for Fire-Resilient Landscapes in Portugal Is Riddled with Fallacies: A Critical Review of “FIRELAN” by Magalhães et al., 2021

“…Evidently, it is not possible for Magalhães et al to ensure the effectiveness of less flammable land uses, namely their capability to slow down wildfire spread, which is highly dependent on the prevailing weather conditions; they present no quantitative results related to potential fire behaviour showing that tree species composition should change drastically; and the FIRELAN conceptual model lacks the capability to assess the adequacy of various land use types to prevent fire occurrence or mitigate fire behaviour. FIRELAN also lacks the analytical tools required to establish the need to create discontinuities in the landscape (e.g., [16,17]), or to assess the impact of structures such as edges, swales, and ponds on fire rate of spread, fireline intensity, or fire exposure (e.g., [18][19][20]). In each of these cases, assumptions about the fire-proneness of diverse land cover types are simply restated under the form of conclusions concerning their expected effects on fire behaviour.…”

Defining priorities for wildfire mitigation actions at the local scale: insights from a novel risk analysis method applied in Portugal

“…Mitigation options can target different risk components, have different costs, responsibilities and effectiveness (Calkin et al, 2014). Reducing wildfire exposure means decreasing the probability that a wildfire will start and/or spread with high intensity close to a settlement (Oliveira et al, 2020;Jahdi et al, 2023). In this case, mitigation options can be applied in the form of fuel treatments, either strategically located in the landscape or adjacent to settlements.…”