A peculiar history of destruction in the old village of Castel Frentano, central Italy, from reconstruction of landslide effects followed by earthquake damage in 1881

Abstract

Anthropogenic modifications of the landscape (e.g. urbanization, deforestation and agricultural activities) act as geomorphic processes, producing fast changes and instabilities, which often lead to landslides along hillslopes and floodings in lowlands. Anthropogenic modifications have increased with the progress of civilization; therefore, coupling historical information and geomorphological data can provide key information to determine the anthropogenic impacts on landscape evolution. The case of Castel Frentano, a village in the Abruzzo Region (Central Italy), has been analysed to shed light on the causes of its destruction in 1881: during the summer of that year, the village was heavily damaged by a peculiar succession of paroxysmal events, i.e. a massive landslide followed by a strong earthquake. This earthquake induced additional damages to the buildings, due to seismic shaking and slide reactivation. This study involved geomorphological and geological surveys, which were aimed at mapping and defining the main presently active geomorphic processes in the area of interest; moreover, we researched 19th-century historical documents to reconstruct the genesis and evolution of the events that led to landsliding in 1881. Although the study area has always been prone to instability phenomena (due to its local geological and geomorphological characteristics), our results revealed that sliding was most likely triggered by human activities that had strongly modified the hillslope. Historical sources revealed a general hillslope instability that progressively evolved in the 1881 landslide because of deforestation. That deforestation had been carried out for agricultural exploitation on a previously stable territory. In this view, the case of Castel Frentano exemplifies the relationship between human activities, landscape modifications and their consequences in Italy in terms of risks to both natural and anthropogenic environments. This is particularly important to assess at present: in a historical period characterized by economic growth, strong demographic expansion and the consequent fast colonization of natural spaces.