Mapping recent wildfires in Greece and the associated built-up losses

Mediterranean regions are characterized by increasing fire frequency and severity during recent years, threatening ecosystems, infrastructures, and human wellbeing. Greece has been particularly affected with devastating casualties including environmental and socioeconomic losses. Here, we examined five distinct wildfires that took place in Greece during summers 2021 and 2023 with the overall objective to delineate the burned area and quantify possible built-up losses. More specifically, we focused on fire events that occurred in Northern Peloponnese, the Island of Evia, and Eastern Attica during summer 2021, and the recent wildfires at the Rhodes Island and the region of Evros during summer 2023. These regions cover different topographic, land cover and bioclimatic characteristics with also various built-up densities and wildland-urban interfaces. Optical remote sensing observations from the Copernicus Sentinel 2 and the Landsat satellite missions were used to calculate spectral indices such as the Normalized Burn Ratio (NBR) and the dNBR (i.e., the difference between pre- and post-fire NBR) and estimate the total burned area and burn severity. Specific urban features that were affected (i.e., roads, building, etc.) were estimated using auxiliary geospatial information from two openly available datasets (Open Street Maps and Microsoft Building Footprint). Exploring the increasingly available satellite imagery offers novel insights into several natural hazards, including wildfires, providing timely estimates of possible infrastructure losses and supporting decision making.