**1. Introduction**

Mass movement phenomena (i.e., rockfalls, debris flows, shallow landslides, snow avalanches, etc.) play a significant role in the landscape evolution and occur in relation to physiographic, geomorphological, and climatic features and to triggering effects induced by human and/or seismic activity [1–12]. These phenomena cause significant disasters on a global scale every year, and the frequency of their occurrence seems to be on the rise. The expansion of urbanization and the tourism development in particular areas, such as mountainous regions, notably increased the environmental hazards and risks. Moreover, climate extremization and the potential for more severe weather conditions could also be acknowledged as contributing factors. Hence, these events can significantly impact mountain environments, residential areas in avalanche zones, ecosystems, and public infrastructures [13,14].

According to the Emergency Events Database—EMDAT [15], snowfall and snow avalanches are considered natural hazards belonging to hydrometeorological events. Snow avalanches are critical events connected to the sudden instability of snow-covered slopes in geodynamical active mountain regions. Moreover, they are undoubtedly one of the major

**Citation:** Fazzini, M.; Cordeschi, M.; Carabella, C.; Paglia, G.; Esposito, G.; Miccadei, E. Snow Avalanche Assessment in Mass Movement-Prone Areas: Results from Climate Extremization in Relationship with Environmental Risk Reduction in the Prati di Tivo Area (Gran Sasso Massif, Central Italy). *Land* **2021**, *10*, 1176. https://doi.org/10.3390/land10111176

Academic Editor: Giulio Iovine

Received: 8 October 2021 Accepted: 29 October 2021 Published: 2 November 2021

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denudational processes in cold and mountainous areas, representing a huge natural hazard with devastating socioeconomic and environmental impacts [16,17].

Mass movement triggering is linked to sudden changes in the geomorphological features of the slopes and the physical characteristics of the snow cover [18,19], resulting, in turn, from numerous variables in continuous changes, such as the geomorphological characteristics of the site, the static and dynamic climatological trends, the processes of metamorphism of the snowy mantle, and the effects of new snow overloading on a preexisting snow cover caused by the action of wind and seismic events of significant magnitude.

It is crucial to follow different approaches to map snow avalanches to provide correct and valuable hazard assessments. Hazard maps represent significant and essential tools needed to evaluate snow avalanche susceptibility of an area, such as a ski resort [20]. It is possible to distinguish between different types of avalanche hazard maps: inventory maps, such as France Carte de Localisation Probable des Avalanches CLPA, [21], depicting the maximum extends of known avalanches, usually compiled from literature, technical documents, and interviews and supported by air–photo interpretation and field investigations and hazard maps [22,23], outlining zones affected by different degrees of hazard, generally drawn based on known historical events, geomorphological studies, and statistical and/or dynamic computational models. In addition to these thematic maps, several techniques can be used to evaluate avalanche hazards and risks involving the implementation of defense structures, closures, and explosives [24,25]. Since the pioneering works in this research field [26,27], most studies were performed to evaluate the long-term risk on settlements and critical infrastructure. These authors all used solid explosives, investigated shock waves propagating through a snowpack, and showed the distinct damping effect of snow, e.g., [28–30]. According to the literature and technical reports [31–33], the techniques used to evaluate avalanche hazards and risks are different depending on the circumstances. The long-term risk affecting permanent settlements and critical infrastructure is typically managed by conducting hazard mapping during the main steps of the land planning process. On the other side, safety services for ski resorts, ski facilities, and temporary worksites are characterized by closures and explosives (i.e., Obellx® gas exploder) to manage short-term avalanche risk; guides adopt professional route selection to control the exposure of people, and public avalanche forecasters communicate regional avalanche danger to a direct stakeholder who manages their own risk [16].

Moreover, it must be considered that the devastating propagation of a snow avalanche may contribute to the mass wasting of rocks and vegetation being transported along the way and accumulated together with the snow avalanche debris. This induced mass wasting poses longer-lasting damages with more destructive effects [34]. As a result, to completely define the degree of hazard in mass movement-prone areas, dynamic computational models can help to estimate paths and impact pressures in the runout zone [35]. Modeling the avalanche triggering mechanisms is complicated, and this complexity has been widely described in many studies [36,37]. The morphological setting (i.e., terrain and slope), the snowpack, and the meteorological conditions contribute to the avalanche movement and propagation. Based on the interaction of these parameters, the avalanche formation and its propagation can eventually be modeled [38–42]. The models have been largely enhanced with the involvement of recent advanced technologies of Geographic Information Systems (GIS) [43–45], which have become powerful tools for the implementation of required databases to support decision-making activities in land planning, such as over hazardous regions posed as a threat by several geohazards (i.e., landslides and snow avalanches).

The mountain territories of the Abruzzo Region are not immune to the general phenomenon of increased tourists' fruition and related snow avalanche risk. Nevertheless, due to its geographical location and physiographic framework (Figure 1), the Abruzzo Region also shows peculiar meteorological and snow characteristics that differ from the rest of the Alps and Central Apennines [46].

**Figure 1.** Three-dimensional view (from 20 m DTM, SINAnet) of the Abruzzo Region (Central Italy) and main physiographic domains. The red polygon indicates the study area.

The study area is located in the northeastern part of the Abruzzo Region within the Gran Sasso Massif (Figure 1). It is sited in the municipal territory of Pietracamela. It includes, to the south, a wide irregular mountainous landscape dominated by the Corno Grande (2912 m a.s.l.), featuring as the highest peak of the Apennines Chain.

To develop the present study, an integrated and multidisciplinary approach was followed to provide further advancement in snow avalanche hazard assessment methodologies. Combining and integrating morphometric, geomorphological, climatic, and nivological analyses, it was possible to better define the existing relationships between climate extremization and environmental risk reduction in a mass movement-prone area, such as the Prati di Tivo area. This paper focuses on the stepwise approach for a correct snow avalanche assessment by combining the patterns of snow avalanches and the main meteorological features of the study area. Morphometric and geomorphological analyses were carried out to evaluate landslide hazards in this mass movement-prone area, mainly focusing on the dynamic geomorphic action of snow avalanches. The role of the geomorphological and climatic features in the triggering of the avalanches was also evaluated. Furthermore, it describes the safety services and the risk mitigation protocol to perform over a ski facilities area in such a mass movement-prone setting. This work could represent an effective tool in geomorphological hazard studies for high mountainous environments readily available to interested stakeholders, which provides a scientific basis for territorial planning, emergency management, and mitigation measures.
