**6. Conclusions**

This paper presents detailed analyses of the occurrence and distribution of landslides over the hilly piedmont area of Abruzzo Region (Central Italy) in relation to mechanisms and factors that control their evolution in different orographic, lithological, and geological– structural conditions. Historical landslides analysis, supported by GIS-based techniques, was performed through an integrated approach combining literature data and landslide inventories analysis, relationships between landslide types and lithological units, detailed photogeological analysis, and geomorphological field mapping. In detail, the work focuses on three landslide case studies that have undergone several main movements since the 18th century onwards, intending to highlight the multitemporal geomorphological evolution of phenomena and the interplay between morphostructural/geological framework and landslide dynamics. The main landslide cases analyzed and discussed in this paper consist of rotational and translational slide in a complex landslide system on clayey–sandy deposits, characterized by a very rough topography documenting the activity of long-term landslide processes (San Martino sulla Marruccina landslide case); complex landslide system including lateral spreading with rockfalls, rotational and translational movements, characterized by a travertine layer that overlies arenaceous-pelitic and pelitic-arenaceous

deposits (Roccamontepiano landslide case); main earth flow on chaotic allochthonous pelagic deposits with several families of rotational and translational landslides, complex landslides, and rockfalls (Montebello sul Sangro landslide case).

A multidisciplinary and multitemporal analysis allowed us to better characterize the present-day landscape setting of the study area, deriving data from historical information on past and current landslides. Furthermore, this work represents an attempt for the understanding of spatial interrelationship of landslide types, morphostructural setting, and climate regime in the study area. It gives a contribution about the location, abundance, activity, and frequency of landslides in a changing environment, by means of the analysis of historical events and a comparison between the long-term rainfall trends and the distribution of annual landslide occurrences, which shows that landslide dynamics are not directly linked to climate regime variations, but that the most influential factors are represented by the lithological and morphostructural setting. Finally, the work could represent a scientific tool for any study in the future concerning susceptibility, hazard, and risk assessment at different spatial scales, readily available to interested stakeholders for sustainable territorial planning and loss-reduction measures.

**Author Contributions:** Conceptualization, G.E., and E.M.; methodology, C.C., G.P., and E.M.; software, C.C.; validation, G.E., and E.M.; investigation, G.E., C.C., G.P., and E.M.; writing—original draft preparation, C.C., and G.P.; writing—review and editing, E.M.; supervision, G.E., and E.M.; project administration, G.E., and E.M.; funding acquisition, E.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research and the APC was funded by Enrico Miccadei, gran<sup>t</sup> provided by Università degli Studi "G. d'Annunzio" Chieti-Pescara.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the author. The data are not publicly available due to privacy. Images employed for the study will be available online for readers.

**Acknowledgments:** The authors wish to thank the Cartographic Office of the Abruzzo Region by means of the Open Geodata Portal (http://opendata.regione.abruzzo.it/, accessed on 24 October 2020), the Ministero dell'Ambiente e della Tutela del Territorio e del Mare (http://www.minambiente. it/, accessed on 24 October 2020), and the IGMI (Istituto Geografico Militare Italiano) for providing topographic and interferometric data, aerial photos, and orthophotos used for this work. The rainfall data were provided by the Functional Center and Hydrographic Office of the Abruzzo Region (Centro Funzionale e Ufficio Idrografico Regione Abruzzo, Pescara, Italy). The authors wish to thank the anonymous reviewers for their critical review of the paper and their precious suggestions, which significantly improved this manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
