## 3 Results
### Susceptibility Maps  
1. The GIS-Based Approach Combined Various Datasets and Techniques to Assess Susceptibility to Floods and Rockfalls. 2. Digital Elevation Model (DEM) Analysis: DEM Data Provided Elevation Information for Terrain Classification into Low, Moderate, and High Slope Gradients, Indicating Erosion and Instability Risks ([PERSON] et al., 2006 [19]). 3. Flow Direction and Accumulation: Hydrological Models Identified Drainage Patterns and Potential Runoff Pathways ([PERSON] and [PERSON] 2006 [20]). 4. NDVI Calculations: NDVI from Satellite Imagery Assessed Vegetation Cover and Its Influence on Slope Stability ([PERSON] et al., 2005 [12]). 5. Weighted Overlays: Integration of DEM-Derived Slope Classifications, Land Cover Types, and Proximity to Water Bodies Produced Comprehensive Susceptibility Maps. Figure 6 illustrates a susceptibility map that combines DEM-derived slope classifications, land cover types, and proximity to water bodies to depict areas that are highly susceptible to rockfall. At the same time, this classification shows a susceptible area with a high and very high degree, but with a much greater predominance in the upper area due to the much greater slopes of the gorge where several extensive slope stabilization works have been carried out over the years. Figure 5: Rockfall map displaying incidents along National Road 66 and surrounding slopes for specified dates. Figure 7 illustrates a susceptibility map that combines DEM-derived slope classifications, land cover types, and proximity to water bodies to depict areas that are highly susceptible to rockfall combined with extracted affected areas from radar images. Also, a higher degree of susceptibility can be observed, both from the data obtained with radar and from the classification obtained in ArcGIS Pro, in the upper part of the gorge due to the much higher slopes but also due to the orography because the Parang Mountains are predominantly composed of limestone while the Valcan Mountains are composed of both limestone and crystalline shale. It is also not to be neglected that the communication networks, both the road and the railway, have been dug into the walls of the gorge, and the high and very high degrees of susceptibility to falling stones disrupt the smooth flow of traffic, meaning that participants face the unpleasant surprise of encountering rockfalls on cars (Figure 13), or rockfalls blocking the road (Figure 14) or railway. Figure 8 illustrates a susceptibility map that combines DEM-derived slope classifications, land cover types, rainfall, and proximity to water bodies to describe areas that are highly susceptible to flooding. As can be seen, due to the narrowing of the gorge in the northern part of the study area, floods have a lower degree of occurrence. Once it begins to widen from the central part of the study area, a much higher susceptibility can already be observed, which continues in the southern part of the gorge where it widens much more and the slopes gradient decrease. Figure 9 illustrates a susceptibility map that combines DEM-derived slope classifications, land cover types, rainfall, and proximity to water bodies to depict areas that are highly susceptible to flooding with affected areas drawn from radar images. As can be seen, due to the narrowing of the gorge in the northern part of the study area, floods have a lower degree of occurrence. Once it begins to widen from the central part of the study area, a much higher susceptibility can already be observed, which continues in the southern part of the gorge where it widens much more and the slopes decrease ([PERSON] et al., 2022 [21]).