1,4,- 1University of Bari "Aldo Moro", Department of Soil, Plant, and Food Sciences, Italy (onofrio.cappelluti@uniba.it)
- 2Department of Agricultural, Forestry and Food Sciences (DISAFA), University of Torino, 10124, Turin, Italy
- 3Centre of Geographical Studies, Institute of Geography and Spatial Planning, Lisbon and Associated Laboratory TERRA, University of Lisbon, 1600-276, Lisbon, Portugal
- 4CMCC—Fondazione Centro euro-Mediterraneo sui Cambiamenti Climatici, Lecce, Italy
Background: Wildfires in Southern Europe arise from interacting climatic, ecological, and socio-ecological mechanisms.
Drought enhances fuel desiccation, land cover change reshapes vegetation flammability, and the expansion
of the wildland–urban interface (WUI) increases ignition pressure and exposure. Understanding how these drivers
overlap spatially and temporally is essential to identify where reinforcing or decoupled processes shape wildfire
dynamics. This study develops a spatially explicit framework integrating drought variability (Standardized Precipitation–
Evapotranspiration Index, SPEI), Landscape Flammability Classes (LFC), and Wildland–Urban Interface (WUI)
expansion to detect statistically supported hotspots and coldspots of wildfire occurrence across biogeographical
regions.
Methods: We analysed a 20-year dataset (2001–2020) at 12-km resolution, combining number of fire and fire size
with long-term trends in three macro-drivers (SPEI, LFC, WUI). Temporal changes in wildfire parameters were estimated
using generalized linear models with False Discovery Rate (FDR) correction. Trends in SPEI and WUI were
assessed through Mann–Kendall and Kendall tau tests supported by Theil–Sen slope estimation, while LFC change
was derived from land-cover transitions between 2000 and 2018. Finally, a spatial co-occurrence analysis classified
each grid cell as a hotspot, coldspot, or mismatch area based on the degree of alignment between macro-driver
trajectories and wildfire trends.
Results: Significant and candidate hotspots were concentrated in the Anatolian, Continental, and Mediterranean
bioregions, where over 30% of burned areas showed concurrent increases in drought intensity, landscape flammability,
and WUI expansion. The Anatolian bioregion exhibited the strongest increases in WUI (+ 73.4%) and LFC (+ 67.2%),
while the Continental region was dominated by widespread drying (90.5% of its area). Coldspots were mainly located
in the Atlantic region, reflecting coherent declines in both wildfire parameters and macro-drivers. Mismatch zones,
encompassing more than half of the burned area, revealed high spatial variability where fire dynamics diverged
from macro-driver trends, indicating the influence of local-scale or non-mechanistic processes.
Conclusions: The joint analysis of climate variability, fuel continuity and human pressures shows that wildfire patterns
in Southern Europe depend on how the long-term trends of these macro-drivers align or decouple. Hotspots reveal
regions where multiple drivers evolve in the same direction as wildfire activity, whereas mismatch areas highlight
the role of local processes that interrupt large-scale relationships. The framework provides a quantitative basis
How to cite: Cappelluti, O., Ascoli, D., Oliveira, S., Lafortezza, R., Chiriacò, M. V., Sanesi, G., and Elia, M.: Intertwined drivers of wildfire occurrence in Southern Europe: climate, landscape flammability and WUI expansion, 19th Plinius Conference on Mediterranean Risks, Murcia, Spain, 6–9 Oct 2026, Plinius19-20, https://doi.org/10.5194/egusphere-plinius19-20, 2026.
