Ventotene island is located in the eastern part of the Pontine Archipelago (Latium, Italy). Ventotene represents the south-eastern flank of a strato-volcano formed by the superimposition of deposits ejected during both effusive and explosive eruptions, over the last 800.000 years of activity. As regards lithology, the Ventotene island may be subdivided into three sector: a lower part, mostly formed of lava deposits, which reaches its maximum thickness at the southern end of the island, at Capo Arco; an intermediate part, mostly pyroclastic, which forms the central part of the island, overlying the lava series; finally, the upper part, which forms the northern sector of the island, represented by reworked volcanic materials. The whole succession dips toward the NE, with its maximum thickness at Capo Arco, and its minimum at the level of the inhabited part of Ventotene. From a morphological standpoint, the island is characterized by the presence of a slightly dipping plateau, bordered by cliffs with height ranging between 130 m (in the southern sector) and 10 m (in the northern sector). The plateau surface is grooved with flat-bottomed valleys, formed along some the principal of the underlying tuff. The island is affected by a continuous activity of erosional and mass instability processes, caused by exogenous agents (sea wave action, wind abrasion and erosion due to runoff and infiltration water), that are at the origin of a long sequence of erosion and landslides. Even the island geological setup, the rock slide occur mostly along the entire perimeter of the island, in the tuff formation with fall, toppling and sliding mechanisms.The progressive evolution of the cliffs through such processes is heavily reducing the size of the island, at the same time threatening and causing damage to the precious cultural heritage of the Roman era. Considering the high coastal landslide risk and scarce economic resources, it is necessary to define automated procedures which, beginning with field data collected in sample areas, might identify area of highest risk. This article will, therefore, propose a quantitative method for the analysis of landslides based on the application of the Matheson test, implemented in a GIS environment. More specifically, we have developed a computational algorithm based on geomechanical surveys, carried out on different areas of the island for commercial purposes, and considering four failure mechanisms (planar sliding, wedge slip, flexural tipping and tilting block), which have enabled the elaboration of a landslide hazard map in stone formations of tuff cliffs on the island of Ventotene.
Application of the Matheson test implemented in a GIS environment: the Ventotene case study (Latium, Italy).
PARISE, Mario;
2016-01-01
Abstract
Ventotene island is located in the eastern part of the Pontine Archipelago (Latium, Italy). Ventotene represents the south-eastern flank of a strato-volcano formed by the superimposition of deposits ejected during both effusive and explosive eruptions, over the last 800.000 years of activity. As regards lithology, the Ventotene island may be subdivided into three sector: a lower part, mostly formed of lava deposits, which reaches its maximum thickness at the southern end of the island, at Capo Arco; an intermediate part, mostly pyroclastic, which forms the central part of the island, overlying the lava series; finally, the upper part, which forms the northern sector of the island, represented by reworked volcanic materials. The whole succession dips toward the NE, with its maximum thickness at Capo Arco, and its minimum at the level of the inhabited part of Ventotene. From a morphological standpoint, the island is characterized by the presence of a slightly dipping plateau, bordered by cliffs with height ranging between 130 m (in the southern sector) and 10 m (in the northern sector). The plateau surface is grooved with flat-bottomed valleys, formed along some the principal of the underlying tuff. The island is affected by a continuous activity of erosional and mass instability processes, caused by exogenous agents (sea wave action, wind abrasion and erosion due to runoff and infiltration water), that are at the origin of a long sequence of erosion and landslides. Even the island geological setup, the rock slide occur mostly along the entire perimeter of the island, in the tuff formation with fall, toppling and sliding mechanisms.The progressive evolution of the cliffs through such processes is heavily reducing the size of the island, at the same time threatening and causing damage to the precious cultural heritage of the Roman era. Considering the high coastal landslide risk and scarce economic resources, it is necessary to define automated procedures which, beginning with field data collected in sample areas, might identify area of highest risk. This article will, therefore, propose a quantitative method for the analysis of landslides based on the application of the Matheson test, implemented in a GIS environment. More specifically, we have developed a computational algorithm based on geomechanical surveys, carried out on different areas of the island for commercial purposes, and considering four failure mechanisms (planar sliding, wedge slip, flexural tipping and tilting block), which have enabled the elaboration of a landslide hazard map in stone formations of tuff cliffs on the island of Ventotene.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
