## 1 Introduction  
The frequency of forest fires is rapidly increasing in southern Europe, posing major challenges for Greece, Italy, Portugal, Spain, and France [1]. Wildfires can represent a serious threat to human health and infrastructure, as well as ecosystems and biodiversity [2]. More specifically, the impact of wildfires on human health can be either direct, causing severe physical damage due to burns, or indirect, since the exposure to pollutants such as ozone and PM [3] can lead to serious disorders. In addition, large wildfires can damage properties or critical infrastructure, such as electricity grids and houses, resulting in major economic losses [4]. Finally, wildfires play an important role in ecological balance, in which humans are a part of. The increase in fire frequency in the past few years enhances forest degradation and biodiversity loss [5]. In terms of biodiversity, Greece is one of the richest countries in Europe, having the highest number of flora species among the Balkan countries. In fact, it contains over 5700 different species of flora, 20% of which are endemic to the country. Most of these species are located in the northern regions of the country, thanks to the ideal geographic and climate conditions [6; 7]. It seems that species richness of Greece combined with the high risk of fire in the Mediterranean region--because of its hot and dry summers--makes Greece extremely susceptible to wildfires. Consequently, the average annual burned area caused by wildfires has shown an increasing trend in the past decades. During 2001-2017, wildfires burned an average of 55,000 ha per year, most of which was covered by forested areas [8]. Recently, one of the most disastrous wildfires took place in August 2021 in Evia island, where 34,893.5 ha of forest and 1111.6 ha containing houses and infrastructure were destroyed or seriously affected by fire [9]. As a result, it is critical to study how various factors influence the probability of fire occurrence, in order to create a fire risk layer for the Fire Management Geographic Information  
Fire risk expresses the likelihood of a fire occurring during a specific time period and place. The risk is the result of the different hazardous parameters interacting with the conditions of vulnerability, which are present in the region [10]. On the one hand, hazardous parameters describe the danger of fire occurrence and on the other hand, vulnerability expresses the predilection of an area to be negatively affected by wildfire [11]. It is very common for the terms 'fire risk' and 'fire danger' to have interchangeable meanings. The factors that influence the ignition and development of fires constitute the fire danger. Fire ignition can derive from natural causes (mostly thunder), or it can be a result of human activity [12]. According to a study, approximately 93% of fires in Northern Europe are caused by humans, either intentionally or unintentionally [13], and thus the location of populated places and roadways is critical in identifying areas at high risk of fire. The development of fires is influenced by topography, meteorological conditions, fuel condition, and fuel availability [14]. Many studies have shown that vegetation and topography are the key elements responsible for fire severity in many types of forests. [15; 16; 17; 18]. Since topographic features influence the distribution of local climate, topography is an important factor in fire propagation. Fires spread quickly across steep and upward slopes, but slowly in places with a downhill slope [19]. Moreover, the probability of fire occurrence may vary in different elevations on the basis of factors such as temperature and vegetation [20]. The topographic wetness index (TWI) [21] is another parameter that contributes to fire spread and ignition. To a certain extent, TWI simulates the impact of topography to soil and fuel moisture [22; 23]. Geographic information systems (GIS) is mature technology and effective platform to analyze, visualize, and disseminate spatial and temporal data and information.