Prediction Capability of Analytical Hierarchy Process (AHP) in Badland Susceptibility Mapping: The Foglia River Basin (Italy) Case of Study

Badland morphologies are prominent examples of linear erosion occurring on clay-rich slopes and are critical hotspots for sediment production. Traditional field-based mapping of these features can be both time-consuming and costly, particularly over larger basins. This research proposes a novel methodology for assessing badland susceptibility through a multi-criteria decision-making framework known as the Analytical Hierarchy Process (AHP). This methodology, developed and tested in the Foglia River basin of the Marche region (Italy), facilitates the identification and mapping of badland areas. More in detail, our study resulted in the creation of a comprehensive badland inventory and susceptibility map for the 102 km2 study area, identifying 276 badlands using a combination of satellite imagery, historical orthophotos, existing regional inventories, and field inspections. Key predisposing factors, including geological, land use, topographical, and hydrometric elements, were systematically analyzed using the AHP approach. The research findings indicate that badlands develop in medium to steep slopes oriented towards the southern quadrants and in proximity to watercourses; their formation is predominantly influenced by clayey–sandy lithology. The resulting inventory and susceptibility map serve as relevant tools for monitoring, preventing, and mitigating slope instability risks within the region.