Landslide hazard in the Abruzzo Region (Central Italy): landslides case studies in different geomorphological/morphostructural environments

Abruzzo Region (Central Italy) is largely affected by landslide phenomena, widespread from the mountainous to the coastal areas. The area is located in the central-eastern part of the Italian peninsula. It is framed in a complex geological and geomorphological framework, closely connected to the combination of endogenous (morphotectonics) and exogenous processes (slope, fluvial, karst, and glacial processes). Landslide phenomena are linked to the interaction of geological, geomorphological, and climatic factors (instability factors) in response to trigger mechanisms, mostly represented by heavy rainfall events, seismicity, or human action. This work illustrates the results of multidisciplinary analyses carried out in recent years in different physiographic and geomorphological-structural contexts (chain, foothills, fluvial, and coastal areas). These analyses are based on the combination of classic and advanced methods, including morphometric analysis of the topography and hydrography, detailed geological-geomorphological field mapping, geostructural analysis, photogeological analysis, and numerical modeling. Selected case studies are chosen as representative of the main active geomorphological processes affecting different geomorphological/morphostructural environments, with reference to the predisposing and/or triggering factors. The main landslide cases analyzed and discussed in this work consist of: debris flow and rockfalls in a mountain area, widely altered by wildfire events (Montagna del Morrone case); complex landslides systems in the foothills, characterized by a very rough topography documenting the activity of long-term landslide phenomena (Ponzano and San Martino sulla Marrucina cases); sliding and complex landslides (topples and rockfalls) in hilly-piedmont areas, following a heavy snow precipitation event and a moderate seismic sequence (Castelnuovo di Campli case) and induced by episodic and localized cliff recession processes combined with wave-cut and gravity-induced slope processes (Abruzzo rock coast cases). The work outlines the importance of combining geological and geomorphological approaches with detailed field and laboratory data analysis to characterize morphologies, bedrock features, structural features and jointing, superficial continental deposits, and landforms distribution. This allows supporting large-scale analyses to evaluate hazards and risks posed by different landslides with different magnitudes in different environments. This work could represent a practical integrated approach in geomorphological studies for landslide hazard modeling at different spatial scales, readily available to interested stakeholders. Furthermore, it could provide a scientific basis for implementing sustainable territorial planning, emergency management, and loss-reduction measures.