Extreme wildfires continue to be a significant cause of human death and biodiversity destruction within countries that encompass the Mediterranean Basin. Recent worrying trends in wildfire activity (i.e., occurrence and spread) suggest that wildfires are likely to be highly impacted by climate change. In order to facilitate appropriate risk mitigation, it is imperative to identify the main drivers of extreme wildfires and assess their spatio-temporal trends, with a view to understanding the impacts of global warming on fire activity. To this end, we analyse the monthly burnt area due to wildfires over a region encompassing most of Europe and the Mediterranean Basin from 2001 to 2020, and identify high fire activity during this period in eastern Europe, Algeria, Italy and Portugal. We build an extreme quantile regression model with a high-dimensional predictor set describing meteorological conditions, land cover usage, and orography, for the domain. To model the complex relationships between the predictor variables and wildfires, we make use of a hybrid statistical deep-learning framework that allows us to disentangle the effects of vapour-pressure deficit (VPD), air temperature, and drought on wildfire activity. Our results highlight that whilst VPD, air temperature, and drought significantly affect wildfire occurrence, only VPD affects extreme wildfire spread. Furthermore, to gain insights into the effect of climate change on wildfire activity in the near future, we perturb VPD and temperature according to their observed trends and find evidence that global warming may lead to spatially non-uniform changes in wildfire activity.
翻译:地中海盆地国家内的极端野火继续是造成人类死亡和生物多样性破坏的重要原因。最近令人担忧的野火活动趋势(即发生和蔓延)表明,野火很可能受到气候变化的严重影响。为了促进适当减少风险,必须查明极端野火的主要驱动因素,评估其时空趋势,以便了解全球变暖对火灾活动的影响。为此,我们分析2001年至2020年欧洲和地中海盆地大部分地区野火造成的每月烧焦地区,并查明这段时期东欧、阿尔及利亚、意大利和葡萄牙的高火灾活动趋势。我们建立了一个极端的四分回归模型,以高方位预测器描述这一领域的气象条件、土地覆被使用情况和地形。为了模拟预测变量和野火之间的复杂关系,我们利用一个混合统计深度学习框架,使我们能够消除蒸气压力、空气温度和干旱对野火活动的影响。我们的结果显示,VDF、气温变化和气温变化对未来温度和温度变化的影响,对未来气温变化的影响,对气温变化的影响,对气温变化的影响,对气温变化的影响。我们的成果将显著地显示VDD的干旱活动影响到VPD温度,对气温变化的影响。