Modeling the effects of different fuel treatment mosaics on wildfire spread and behavior in a Mediterranean agro-pastoral area. (15th April 2018)

• Record Type: Journal Article
• Authors: Salis, Michele; Del Giudice, Liliana; Arca, Bachisio; Ager, Alan A.; Alcasena-Urdiroz, Fermin; Lozano, Olga; Bacciu, Valentina; Spano, Donatella; Duce, Pierpaolo
• Is Part Of: Journal of environmental management. Volume 212(2018)
• Page Start: 490
• Page End: 505
• Publication Date: 2018-04-15
• Subjects: Fuel treatments -- Burn probability -- MTT algorithm -- Mediterranean areas -- Fire management -- Fire risk; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2018.02.020
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Wildfire spread and behavior can be limited by fuel treatments, even if their effects can vary according to a number of factors including type, intensity, extension, and spatial arrangement. In this work, we simulated the response of key wildfire exposure metrics to variations in the percentage of treated area, treatment unit size, and spatial arrangement of fuel treatments under different wind intensities. The study was carried out in a fire-prone 625 km 2 agro-pastoral area mostly covered by herbaceous fuels, and located in Northern Sardinia, Italy. We constrained the selection of fuel treatment units to areas covered by specific herbaceous land use classes and low terrain slope (<10%). We treated 2%, 5% and 8% of the landscape area, and identified priority sites to locate the fuel treatment units for all treatment alternatives. The fuel treatment alternatives were designed create diverse mosaics of disconnected treatment units with different sizes (0.5–10 ha, LOW strategy; 10–25 ha, MED strategy; 25–50 ha, LAR strategy); in addition, treatment units in a 100-m buffer around the road network (ROAD strategy) were tested. We assessed pre- and post-treatment wildfire behavior by the Minimum Travel Time (MTT) fire spread algorithm. The simulations replicated a set of southwestern wind speed scenarios (16, 24 and 32 km h −1 ) and the driest fuel moisture conditions observed in the study area. Our results showed that fuel treatments implemented near the existing road network were significantly more efficient than the other alternatives, and this difference was amplified at the highest wind speed. Moreover, the largest treatment unit sizes were the most effective in containing wildfire growth. As expected, increasing the percentage of the landscape treated and reducing wind speed lowered fire exposure profiles for all fuel treatment alternatives, and this was observed at both the landscape scale and for highly valued resources. The methodology presented in this study can support the design and optimization of fuel management programs and policies in agro-pastoral areas of the Mediterranean Basin and herbaceous type landscapes elsewhere, where recurrent grassland fires pose a threat to rural communities, farms and infrastructures. Highlights: Fuel treatment spatial arrangement, unit size and area treated affect wildfire spread. Treating fuels nearby roads is the most efficient strategy for containing wildfires. Fuel treatments on large size units perform better than those on small units. Differences in the effectiveness of fuel treatments are amplified at high wind speed.