## 2 Study Area
### Morphology  
The island is predominantly mountainous, with approximately 90% of its surface covered by steep terrain. The highest peaks are Stavrota (1182 m), Elati (1126 m), and Saint Ilias (1014 m). The largest lowland area is located in the south, in the Vasiliki region (Figure 1). The landscape also features deep V-shaped valleys, such as those in Roupakias and the Melissa Gorge, which are primarily the result of intense tectonic activity [11].  
Using a Digital Terrain Model (DTM) with a 25 m ground resolution, provided by the National Cadastre & Mapping Agency S.A. (Attica, Greece), a shaded relief map was generated (Figure 1), which served as the base layer for the hazard maps.  
As slope characteristics strongly influence hazard susceptibility, both a Morphological Slope Map and a Slope Aspect Map were created. The Morphological Slope Map shows that the island is mostly covered by mild slopes (5.1-15\({}^{\circ}\)), which make up 33.9% of the total area (Figure 2). Steep slopes greater than 25\({}^{\circ}\), which are more vulnerable to landslides and erosion, occupy 20.94% of the island.  
Figure 2a uses a color-coded system to classify slope steepness following the method of [PERSON] et al. (2004) [12]. The main part of Lefkas Island consists of very mild to mild slopes  
Figure 1: Digital Terrain Model of Lefkas Island indicating the peaks, plains and deep valleys on the Island. The small map presents the geographic location of the island in Greece.  
Figure 2: (**a**) Morphological Slope Map of Lefkas Island and (**b**) Slope Aspect Map. Pie charts present the percentage of area occupied by the various categories.  
(53.92%), making it highly suitable for human activities, while steep and very steep areas (20.93%) require specialized approaches for land management and development. Specifically:  
* Very Mild Slopes (<5\({}^{\circ}\)), shown in green, cover 20.0% of the island. These areas are mainly located in valleys and lowland regions, particularly in the northeastern and central parts of the island and are generally more suitable for development and agriculture.
* Mild Slopes (5-15\({}^{\circ}\)), displayed in light green, represent the largest portion at 33.9%. They are widely distributed across the island, especially in inland areas, forming a transitional zone between flat lands and hilly terrain.
* Marginally Steep Slopes (15-25\({}^{\circ}\)), colored yellow, occupy 25.1% of the land. These zones typically surround the hillier areas and appear in bands across mid-elevation regions, indicating moderate slope gradients.
* Steep Slopes (25-35\({}^{\circ}\)), marked in orange, cover 15.7% of the island. These are concentrated along ridges and elevated zones, particularly on the western and southern flanks, where terrain becomes significantly more rugged.
* Very Steep Slopes (>35\({}^{\circ}\)), shown in red, account for 5.3% of the area. These are found in isolated patches on sharp ridges and coastal escarments, indicating the steepest and most erosion-prone parts of the island.  
The Slope Aspect Map (Figure 2b) classifies terrain based on the direction that slopes face. East-facing slopes (22.5-157.5\({}^{\circ}\)) dominate the island, covering approximately 43% of the surface and receiving strong morning sunlight. West-facing slopes (202.5-337.5\({}^{\circ}\)) follow with 39.2%, aligning with regions more exposed to prevailing weather systems and frequent landslides along the western coastline. South-facing slopes (157.5-202.5\({}^{\circ}\)), covering 8.49%, experience higher solar radiation and tend to be drier, while north-facing slopes (337.5-22.5\({}^{\circ}\)), accounting for 9.15%, are generally cooler and moister. Flat areas are minimal (0.2%) and mainly located in coastal or lowland zones. These orientations influence microclimatic conditions such as moisture retention, exposure to prevailing winds, and vegetation growth, which are important for hazard modeling and land-use planning.