No abstract

Abstract. Large wildfires across parts of France can cause devastating damages which put lives, infrastructures, and natural ecosystem at risk. One of the most challenging questions in the climate change context is how these large wildfires relate to weather and climate and how they might change in a warmer world. Such projections rely on the development of a robust modeling framework linking wildfires to atmospheric variability. Drawing from a MODIS product and a gridded meteorological dataset, we derived a suite of biophysical and fire danger indices and developed generalized linear models simulating the probability of large wildfires (> 100 ha) at 8-km spatial and daily temporal resolutions across the entire country over the MODIS period. The models were skillful in reproducing the main spatio-temporal patterns of large wildfires across different environmental regions. Long-term drought was found to be a significant predictor of large wildfires in flammability-limited systems such as the Alpine and Southwest regions. In the Mediterranean, large wildfires were found to be associated with both short-term fire weather conditions and longer-term soil moisture deficits, collectively facilitating the occurrence of large wildfires. Simulated probabilities during the day of large wildfires were on average 2–3 times higher than normal with respect to the mean seasonal cycle. The model has wide applications, including improving our understanding of the drivers of large wildfires over the historical period and providing a basis to estimate future changes to large wildfire from climate scenarios.

No abstract

The WUI expansion and climates changes are causing an increasing number of dramatic consequences on the socio-ecosystem in Southern Europe. In France, to reduce the fire threat to infrastructure and human lives, a specific prevention policy provides for many regulatory measures to address forest fire risk in urban planning and forest management. This approach to assessing risk is highly technical and hazard-centred. The shortcomings are the difficulty in appropriating the issue for those who do not have this standardised approach and legitimise less attention paid to individual and collective practices having an effect on vulnerability. Our research focuses on landscape as a means of analysing the representation of forest fire risk by local stakeholder groups. According to the European Landscape Convention, landscape is defined as 'an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors...'. Landscape therefore has both a factual and a subjective value. As an intermediary tool, the landscape allows an inclusive dialogue between various stakeholders since it belongs to the common register and does not have an immediate scientific connotation (Derioz, 2008). On this background, we develop a landscape mediation on forest fire risk to analyse how can landscape help to build a shared risk knowledge in local communities. Landscape mediation is an engineering of public involvement applied to the landscape which eases mobilising stakeholder experience and feelings in territorial diagnostic and spatial planning (Paradis, 2010). We experiment the benefits of landscape mediation to develop a local risk culture by using a case study in Martigues city in the south-east of France. The study site is subject to strong development pressure due to its proximity to the Aix-Marseille Provence metropolitan area, is located nearby two forested areas - Côte Bleue and Castillon forests - which are regularly affected by fires, and has a scattered residential area and therefore a relatively large WUI zone. The landscape mediation project consists of two stages. In spring 2022, residents of the study site are invited to participate in a walking tour through their living area. Using a booklet, the participants assess the characteristics of the landscape and describe the uses of the WUI and its associated fire risk attributes. A collective risk knowledge emerges from sharing contrasting feelings and opinions on WUI and ways to limit vulnerability individually and collectively. In a second stage, the participants present their landscape diagnostic and their views and concerns on forest fire risk prevention management to a group of local stakeholders representative of spatial planning and forest fire risk experts. The diversity of thought reveals new ideas that benefit spatial planning initiatives. This landscape mediation is a collaborative approach to increase public acceptance of forest fire management placing the inhabitant in a collective consideration of vulnerability reduction in his living area. The research helps sharing residents' perceptions of forest fire with decision-makers and fire risk experts to better understand how the community influences action or inaction on forest fire risk prevention management.

No abstract