In Southern Europe, Portugal has registered the largest number of wildfires and the second largest burned area [1]. Fuel Breaks are one of the ways of prevention and containment of wildfires present in legislation (Decree-Law nº 82/2021). However, the measures and standards that regulate Fuel Breaks lack scientific validation to assess their effectiveness.
This study aims to evaluate the effect of fuel management of Fuel Breaks and the effect of forest type on surface fire behavior. Thirty pairs of Managed Areas vs. Non-Managed Areas were sampled. These were distributed throughout the Central Region of Portugal, in ten eucalyptus stands, ten maritime pine stands, and ten mixed stands of eucalyptus and other species. Field data, including the loads and structure of fuels, fuel moisture and micrometeorological information, were collected and used to develop fuel models and perform surface fire behavior simulations in Behave Plus 6 Beta. The results show that only one third of the statistical tests showed significant differences (Table 1) in surface fire behavior between Managed and Unmanaged areas.
Table 1.
Descriptive statistics and Wilcoxon test for fire behavior in managed vs. unmanaged areas of Eucalyptus, Maritime Pine and Mixed Stands.
Likewise, only one statistical test (out of 12) showed significant differences in fire behavior between the three types of stands. Our results show that the reduction in fuel load and depth in Managed areas was annulated by the more severe meteorological conditions (stronger wind speed and lower moisture) observed in these areas. However, it should be taken into consideration that this study only assessed surface fire. Despite these results, Fuel Breaks are an important instrument of prevention and containment of wildfires; they allow better access to means of combat and decrease the likelihood of ignition from, for example, roads and power transmission lines. On the other hand, different results would probably be obtained by including crown fire simulations and more severe weather scenarios.
Author Contributions
Conceptualization, M.P., A.O. and J.S.; methodology, M.P., A.O. and J.S.; software, M.P. and A.O.; validation, M.P. and A.O.; formal analysis, M.P., A.O., J.S. and P.F.; investigation, M.P., A.O. and J.S.; resources, J.S.; data curation, M.P., A.O. and J.S.; writing—original draft preparation, M.P. and A.O.; writing—review and editing, J.S. and P.F.; visualization, M.P., A.O., J.S. and P.F.; supervision, J.S.; project administration, J.S.; funding acquisition, J.S. All authors have read and agreed to the published version of the manuscript.
Funding
This research was carried out within the scope of the InduForestFire Project-CIF/MOS/0129/2018 (Interdisciplinary Methodologies for the Protection of Industrial Areas to Forest Fires), funded by national funds through the FCT–Fundação para a Ciência e a Tecnologia-Portugal. A.O. received support from the FCT (Fundação para a Ciência e a Tecnologia).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Acknowledgments
We thank to Mauro Nereu for his collaboration in the statistical analysis and to Miguel Peixoto for his contributions in the fieldwork.
Conflicts of Interest
The authors declare no conflict of interest.
Reference
- San-Miguel-Ayanz, J.; Durrant Houston, T.; Boca, R.; Liberta’, G.; Branco, A.; De Rigo, D.; Ferrari, D.; Maianti, P.; Artes Vivancos, T.; Costa, H.; et al. Forest Fires in Europe, Middle East and North Africa 2017; Publications Office of the European Union: Luxembourg, 2018. [Google Scholar]
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