Landslide hazard zonation of slopes susceptible to rock falls and topples

Abstract

Abstract.A landslide hazard zonation is a division of the land surface into areas, and the relative ranking of these areas according to degrees of actual or potential hazard from landslides on slopes. Zonation from scientific research does not generally imply legal restrictions, but can be useful to those people who are charged with the land management, by providing them with information that is indispensable for planning and regulation purposes. This paper presents a zonation of rock slopes in carbonate mountains on the boundary to the east of the valley of the Sele River (Campania, southern Apennines of Italy). The mountains are severely affected by rock falls and topples, and the related hazard is, therefore, very high; the presence of inhabited areas (the towns of Valva, Colliano and Collianello) and other human infrastructures at the slope foothills make these phenomena extremely dangerous to the anthropogenic environment. The area is highly seismic, as experienced on the occasion of several moderate to strong earthquakes that have hit this sector of the Apennines. According to the zonation proposed here, the ridge of Mount Valva and Mount Marzano is subdivided into four main areas on the basis of the processes which take place in the different sectors of the mountains: the source area, the talus slope, the rock-fall shadow (where scattered outlying boulders are present), and the safe area (outside of the reach of fallen blocks).The four sectors were identified through air-photo interpretation and detailed field surveys, aimed in particular at characterizing and interpreting the main rock mass joint patterns, and their relative orientation with respect to the local slope direction. Geological, morphological and structural analyses permitted one to evaluate and classify those parts of the slope that are more susceptible to detachment of rocks, and to identify the more diffuse types of failure. Due to high seismicity of the study area, particular attention was given to the evaluation of the seismic susceptibility to rock falls, by applying two methods recently proposed in literature. Results from this phase of the study were then integrated by adCorrespondence to: M. Parise (cerimp06@area.ba.cnr.it) ditional information from historical research on slope movements occurred previously in the area.The landslide hazard zonation, shown on large-scale cartography, could be compared to maps depicting the distribution and typology of the anthropogenic activities, and thus constitutes a useful tool for administrators and planners, in order to evaluate the hazards related to slope movements, and the vulnerability of settlements, roads, and other manmade infrastructures.

Slope processes in weathered volcaniclastic deposits within the city of Naples: The Camaldoli Hill case

“…The topography downslope from the detachment zone controls the evolution of the mass movement after the initial phase of fall or topple (Hungr et al, 1999;Wieczorek et al, 1999;Parise, 2002). In the case of slopes with more or less gradual gradient, detached blocks may move and travel for long distance.…”

Rockfall hazard assessment along a road in the Sorrento Peninsula, Campania, southern Italy

“…Inspection of the geographical distribution of fatal landslide events in Italy (Salvati et al 2003(Salvati et al , 2010 reveals that in the Campania region the geological and morphological conditions are prone to rockfalls, and the hazard posed by rockfalls is severe (Parise 2002). In particular, the Sorrento Peninsula, along the Tyrrhenian coast between Naples and Salerno, is as a ''hot spot'' with frequent fatal rockfall events.…”

Regional-scale landslide inventory, central-western sector of the Basilicata region (Southern Apennines, Italy)

“…Due to different predisposing factors such as high uplift rates, lithological features and the morphostructural setting (Borgomeo, Hebditch, Whittaker, & Lonergan, 2014;Di Leo, Gioia, Martino, Pappalardo, & Schiattarella, 2011;Revellino, Grelle, Donnarumma, & Guadagno, 2010;Santangelo, Gioia, Cardinali, Guzzetti, & Schiattarella, 2013; among others), the Southern Italian Apennine is significantly affected by mass movement processes, which play a key role in landscape evolution (Cendrero & Dramis, 1996;Di Leo et al, 2011;Gioia, Di Leo, Giano, & Schiattarella, 2011) and have a strong impact on human activity (Guzzetti, 2000;Lazzari, Geraldi, Lapenna, & Loperte, 2006;Naudet et al, 2008;Parise, 2002). In a similar morphostructural setting where landslide processes coexist with a growing human pressure, land use planning and hazard evaluation are a critical issue for the sustainable development and effective control of economic losses and casualties related to landslide occurrence.…”