The present study shows the result of a rock fall hazard evaluation of the area downstream the Norman Castle that overlooks Forza d’Agro (Messina Province – Italy). The study was aimed at evaluating the penetration capacity of a rockfall in the inhabited center, to evaluate the number of houses involved in the transit area of the boulders. On the basis of the data obtained, a hazard assessment was developed that took into account not only the type and magnitude of the landslide phenomenon, but also the probability of occurrence of the event or its return time.
The article presents the results of a geological study for the rock fall hazard assessment of the historical center of the town of Forza d’Agrò (Messina Province – Italy). The study was commissioned by the city municipality to detail the risk area (code:097-5FZ-007) indicated in the Regional Geomorphological Structure Plan (PAI) of Sicily River Basin District [1], involving the most part of the old town of Forza d’Agrò.
The study area is located on a narrow ridge that develops in the NW-SE direction, ending at the Norman Castle, which descends from the town towards the sea in a south-easterly direction up to Capo Sant’Alessio, a promontory where the ruins of another Castle are located along the Ionian coast line between Messina and Taormina.
From a geostructural point of view, the area under observation is affected by the frontal part of the complex system of geological units, corrugated and superimposed, which emerge along the entire north-eastern sector of Sicily
In particular, it can be observed that the western part and the top of the ridge are characterized by the outcrop of dolomites and crystalline limestones from the Mandanici unit. The outcrop is conditioned by the presence of a fault; direct NW-SE, which lowers the dolomites and crystalline limestones towards the valley. The same fault intersects another left trans current fault, developed in the NE-SW direction.
