Burn Severity Drivers in Italian Large Wildfires

Abstract

The increase of wildfire incidence in highly populated areas significantly enhances the risk for ecosystems and human lives, activities and infrastructures. In central and southern Italy, recent decades’ fire records indicate that 2007 and 2017 were extreme years in terms of the number of fires and total burned area. Among them, we selected large fire events and explored their features and drivers of burn severity. We used a standardized extraction procedure to identify large wildfires (>100 ha) from the MODIS burned areas database and Landsat multi-spectral images. We mapped burn severity with the Relative Difference Normalized Burn Ratio index and explored the main drivers of severity using topographic, land-cover and anthropogenic predictors. We selected 113 wildfires for a collective total burned area of over 100,000 ha. Large fires were more frequent in the southern than in the central and northern regions, especially in July and August. The average fire size was about 900 ha and occurred mainly in shrublands (30.4%) and broadleaf forests (19.5%). With a random forest model, we observed that the highest severity occurred in conifer plantations and shrublands, in highly populated areas and at lower elevations. Burn severity models, at the landscape or regional scales, can be very useful tools for pre- and post-fire forest management planning.

Exploring Drivers of Wildfires in Spain

“…This is in line with the study on wildfires in the European Mediterranean region [6] showing that forests experienced a more frequent occurrence of fires than other LUC types. This finding also closely aligns with a recent study conducted by [49] in Italy, which suggests that shrubland and forests, particularly coniferous forests, are prone to burning within the Mediterranean biome. The increased risk is attributed to such factors as species composition, fuel accumulations, and the impact of drier and hotter climate conditions during the fire seasons.…”

“…In our study, we used Principal Component Analysis (PCA). Recently, PCA has been applied to investigate the diverse drivers of wildfires, encompassing climatic, socioeconomic, and topographical factors on different eco-biome types around the world [25,29,30,49]. Many studies have compared the patterns of association between wildfires and environmental [17,51] or human-caused [23,52] drivers of wildfires in the EU-MED region.…”

In-between Environmental Sustainability and Economic Viability: An Analysis of the State, Regulations, and Future of Italian Forestry Sector

“…The data relating to the last decade indicate that, every year, around 60,000 hectares of forest and woodlands were burned, with an average area per event of just over 10 hectares, which is slowly growing over time [136]. Critical years, such as 2007, recorded more than 10,000 fire events per season, involving around 220,000 hectares of wooded area, with an average area of around 20 hectares per fire [137]. Most of the economic damage is caused by fires which fall within the size class between 5 and 50 hectares and which have affected, on average, more than 40% of the burnt area [136].…”

Fire Vulnerability, Resilience, and Recovery Rates of Mediterranean Pine Forests Using a 33-Year Time Series of Satellite Imagery

“…Although they occur in relatively small proportions, they catastrophically damage the landscape, countries' economies, and the lives of their citizens (e.g., EWEs in Portugal in 2017, Spain in 2019 and 2022 and, most recently, Greece in 2023). The scientific community has referred to them as "sixth-generation wildfires or megafires" [3][4][5][6][7]. Society faces a significant challenge as these high-severity wildfires become increasingly inevitable due to rural abandonment and climate change.…”