## 1 Introduction  
Greece in the 2021 fire season suffered from one of the greatest ecological disasters caused by wildfires. Especially in the first days of August, an intense prolonged heatwave struck Greece making it the worst that the country faced in almost 34 years. During this period of extreme conditions (27 July to 16 August 2021) in the Greek territory, many wildfires broke out due to the drought that increased wildfire vulnerability. All the means available, from the fire brigade to the local authorities and support from other countries, were used to fight these fires. In addition, evacuations of settlements were performed alongside the use of 112 to send alert messages to citizens, while the Copernicus Emergency Management Service (EMS) was also activated for rapid mapping of the wildfires in most cases [1]. Over the last couple of years, climate change has dramatically affected the Mediterranean region. The vulnerability of this region to drought and rising temperatures has led to severe ecological disasters annually. Specifically, Greece has been dealing with great environmental catastrophic events due to wildfire incidents and remarkably strong heatwaves [2]. The assessment of the wildfires' effect spatially provides a leading role in the documentation of vulnerable areas in different timescale evaluations [3, 4]. Fire incidents constitute a dynamic process in planet Earth alteration affecting the global climate system [5]. Lately, wildfires show an increased occurrence, especially during the summer months, causing a rise in the overall period of the fire season [6]. The Mediterranean countries have been damaged over the last couple of years, due to extensive fire incidents causing irreversible damage to the environment [7]. Especially, high mountain regions characterized by Mediterranean climates seem to be more vulnerable to wildfire incidents due to the occurrence of high rainfall intensity in sparse vegetation cover areas [8]. Fire impacts on vegetation, soil, atmosphere, and society are dependent on fire characteristics such as severity and size [9]. Particularly, in Mediterranean ecosystems where fires occur in summer, the increased temperatures and evapotranspiration succeeded by the increased precipitation in autumn cause alterations to the ecosystems including increased soil loss [10]. Geospatial intelligence (GEOINT) has as a basic principle, the collection, analysis, and combination of all the available data, both geospatial and satellite imagery for Earth's geographical area, so as to utilize them in creating useful products in planning, decision making, and emergency response [11]. The integrated use of remote sensing and GIS proved very important in disaster management, with satellite imagery providing a synoptic view, spatiotemporal changes monitoring, and of course sufficient spatial coverage alongside GIS, which enables the utilization of all the geospatial information available. The capabilities of remote sensing for this purpose can be found in their operational use and their damage assessment after a wildfire event [12]. The use of satellite-based remote sensing in wildfires is well-known in the literature. For the mapping of burned areas, plenty of methods have been developed [13] with the use of multispectral data through the decades, including spectral indices among them such as the burn area index (BAI) [14] and normalized burn ratio (NBR) [15]. Additionally, with the use of satellite imagery, not only the burned area but also further information regarding the impact can be retrieved, as in the case of the dNBR [16], where burn severity can also be assessed. In addition, the combination of remote sensing with GIS in the case of wildfires provides a wide range of geospatial information regarding the post-fire period including the mapping of burned areas, soil erosion estimation, and recovery of the ecosystems [17].