Assessing wildfire hazard in the wildland-urban interfaces (WUIs) of Central Portugal

Abstract

Abstract In Portugal, as in other parts of the world, the rapid growth of housing in and near the wildland–urban interface (WUI) increases the wildfire risk to lives and structures. To reduce this risk, it is necessary to identify WUI housing areas that are more susceptible to fire. The goal of our study was to assess wildfire hazard in the Central Region of Portugal and also in the contact with the 60 373 km of WUIs existing in the study area. The degree to which wildfire is a hazard to the landscape and the different urban interfaces areas was assessed using the spatial arrangement of land use/land cover (LULC), topography and historical incidence of burnt area. The results show that in more than half of the Central Region territory the wildfire hazard is high or very high, however, most of the WUI are in contact with low or very low hazard classes, in a total of 87% of the segments. The LULC analysis in the different wildfire Hazard classes in WUI contact areas shows that agricultural crops are predominant in the low and very low hazard classes, while in the very high and high hazard classes shrub communities, and coniferous and scrub forests dominate, respectively. These results suggest that agricultural land around isolated houses and villages can act as a buffer against wildfires. The analysis of spatial variations in wildfire hazards at landscape/municipal and at the WUI level can assist in designing appropriate prevention measures and improving the effectiveness of fire prevention, however wildfire patterns depend on several other variables that need to be included in the wildfire risk analysis.