On the key role of droughts in the dynamics of summer fires in Mediterranean Europe

Abstract

Summer fires frequently rage across Mediterranean Europe, often intensified by high temperatures and droughts. According to the state-of-the-art regional fire risk projections, in forthcoming decades climate effects are expected to become stronger and possibly overcome fire prevention efforts. However, significant uncertainties exist and the direct effect of climate change in regulating fuel moisture (e.g. warmer conditions increasing fuel dryness) could be counterbalanced by the indirect effects on fuel structure (e.g. warmer conditions limiting fuel amount), affecting the transition between climate-driven and fuel-limited fire regimes as temperatures increase. Here we analyse and model the impact of coincident drought and antecedent wet conditions (proxy for the climatic factor influencing total fuel and fine fuel structure) on the summer Burned Area (BA) across all eco-regions in Mediterranean Europe. This approach allows BA to be linked to the key drivers of fire in the region. We show a statistically significant relationship between fire and same-summer droughts in most regions, while antecedent climate conditions play a relatively minor role, except in few specific eco-regions. The presented models for individual eco-regions provide insights on the impacts of climate variability on BA, and appear to be promising for developing a seasonal forecast system supporting fire management strategies.

Spatial Pattern of the Seasonal Drought/Burned Area Relationship across Brazilian Biomes: Sensitivity to Drought Metrics and Global Remote-Sensing Fire Products

“…Generic indices as the FWI produced as a global database [83], might then not be equally suitable for the whole country with contrasted functional biomes. The SPEI index was finally poorly correlated to BA in our study area although showing good correlations in other biomes [84].…”

Extreme wildfire events are linked to global-change-type droughts in the northern Mediterranean

“…Only the weather and fuel conditions of the day of fire occurrence were analyzed because the main runs of large fires often occur on the first day in this part of the Mediterranean. The Van Wagner, 1987) were used as proxies of fuel dryness. The DMC is generally associated with the moisture content of slow drying surface fuels and is computed from daily rainfall, relative air humidity and air temperature during and prior to the fire day.…”

“…In a large number of ecosystems, anthropogenic ignitions are dominant and dead or live biomass is rarely limiting (Krawchuk et al, 2009;Pausas and Fernández-Muñoz, 2012). In these regions, fuel dryness therefore mainly regulates wildfires (Abatzoglou and Williams, 2016;Littell et al, 2016;Nolan et al, 2016;Fernandes et al, 2016;Turco et al, 2017). But while climate change is expected to increase the frequency and intensity of droughts in regions such as the Mediterranean (Hoerling et al, 2012), our understanding of the impact of increasing drought on EWE remains incomplete because of still-unresolved uncertainties.…”

Flame filtering and perimeter localization of wildfires using aerial thermal imagery

“…[1][2][3] Moreover, some authors have forecasted a further rise in fire seasons' length and severity for the near future. [4][5][6] In the event of a wildland fire, situational awareness is of the utmost importance to guarantee the safety of emergency responders and boost the efficacy of suppression jobs. Furthermore, being able to accurately determine the geographical location of the fuel burning interface and its rate of spread could be helpful to calibrate a number of data-driven fire spread simulators.…”