M. Parise

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

Rockfalls are common in the steep and vertical slopes of the Campania carbonate massifs and ridges, and frequently represent the main threat to the anthropogenic environment, potentially damaging urban areas, scattered houses, roads, etc. Despite the generally limited volumes involved, the high velocity of movement (from few to tens of metres per second) poses rockfalls among the most dangerous natural hazards to man. Evaluating the rockfall hazard is not an easy task, due to the high number of involved factors, and particularly to the difficulty in determining the properties of the rock mass. In this paper, we illustrate the assessment of the rockfall hazard along a small area of the Sorrento Peninsula (Campania region, southern Italy). Choice of the site was determined by the presence of a road heavily frequented by vehicles. In the area, we have carried out detailed field surveys and software simulations that allow generating simple rockfall hazard maps. Over twenty measurement stations for geo-mechanical characterization of the rock mass have been distributed along a 400-m-long slope of Mount Vico Alvano. Following the internationally established standards for the acquisition of rock mass parameters, the main kinematics have been recognized, and the discontinuity families leading to the different failures identified. After carrying out field experiments by artificially releasing a number of unstable blocks on the rock cliff, the rockfall trajectories along the slope were modelled using 2-D and 3-D programs for rockfall analysis. The results were exploited to evaluate the rockfall hazard along the threatened element at risk.

Introduction to the special issue “Landslides: forecasting, hazard evaluation, and risk mitigation”

The papers collected in this special issue of Natural Hazards were originally presented as oral or poster contributions in the sessions ‘‘Innovative approaches for evaluation of the landslide hazard and mitigation of the landslide risk’’ and ‘‘Landslide forecasting’’, which were part of the scientific program of the Geoitalia 2009 meeting, the 7th Italian Forum of the Earth Sciences, held in Rimini, Italy, from 9 to 11 September 2009. The eighteen papers comprising the special issue of Natural Hazards discuss topics related to techniques, tools, and methods for landslide identification, forecasting, hazard evaluation, and the mitigation of landslide risk. The issue opens with the two keynote lectures invited in the sessions: in the first keynote, Jaboyedoff and co-workers review the application of light detection and ranging (LIDAR) technology for landslide investigation, including the study of slides, rockfalls, and debris flows. The authors discuss critically the application of LIDAR very-high-resolution terrain elevation data for the detection and characterization of landslides, for hazard assessment and susceptibility modeling, and for landslide monitoring and modeling. In the second keynote, Günther and co-workers, discuss a GIS-based deterministic approach for the spatial evaluation of the geometrical and kinematical properties of rock slopes. Based on spatially distributed directional information on planar geological fabrics, and DEM-derived topographic attributes, the internal geometry of the rock slopes is characterized. The obtained information, in combination with hydraulic and strength data on the geological discontinuities, can be used to prepare scenario-based rock-slope stability evaluations, at different geographical scales.

Evaluating the impact of quarrying on karst aquifers of Salento (southern Italy)

Abstract This paper describes a case study in the Salento karst (Apulia, southern Italy) in a site that has been intensively used to quarry limestones in the last 30 years. After quarrying activity had stopped, the site was transformed into legal and illegal landfills where solid and liquid wastes have been repeatedly dumped, with serious consequences for the groundwater resources. In this paper, through a geological, petrographical and hydrogeological approach, we attempt to assess the consequences of the anthropogenic activities on the local hydrogeology, with particular regard to the surficial aquifer that is contained in the Plio-Quaternary calcarenites cropping out in the area. Application of some well-known methods to assess the vulnerability of aquifer systems to contamination by human activities (DRASTIC, SINTACS, LeGrand and GOD) highlights the limits of such an approach in karst environment, and the necessity to include in the methods data strictly related to the peculiarity of karst. This is further evidenced by application of the EPIK method, specifically designed for karst areas. The final part of the paper focuses on the need of a thorough understanding of the hydrogeological setting for a better management and policy action of karst environments.

The Experience Of Southern Apulia (Italy) Coastal Karst Aquifer:Indications For The Management

Prediction of the salt water intrusion in coastal karst aquifers is a key issue in several regions of the world. Southern Apulia (Italy) hosts a huge aquifer of karstified lime-stones, that provides 90% of the water demand of this sub-region. The exploitation of the aquifer currently exceeds its natural recharge capacity. The groundwater in wide coastal areas of the sub-region underwent an increase of the salt content. Salinization of the groundwater in such an aquifer cannot be predicted by means of conventional models. An effective model for a quantitative prediction of the fluid flow and transport of solute in the aquifer, aimed at a better understanding of the phenomenon, is there-fore needed. This model should account for the discrete nature of the aquifer. In this paper, several situations are reported in order to describe the importance of the inhomogeneities (fracture systems, fault zones, karst conduit, preferential flow levels) in the salinization process of the southern Apulia karst aquifer. l Introduction Southern Apulia (Salento sub-region) is a typical example of karst coastal aquifer. Within the last decades, the total withdrawals have largely exceeded the natural recharge capacity of the aquifer. As a consequence the aquifer has undergone a strong salinization. The prediction of the response of the aquifer to planned exploitations has been generally carried out by means of porous-like medium models or semi-empirical laws, leading sometimes to erroneous evaluations. To help the authorities in the management of the water resource, new tools for the prediction are required. 2 Hydrogeological outline of southern Apulia Salento is a peninsula of the south-eastern part of Italy. Its basement consists of lunestones and lunestone-dolostones of Cretaceous age (Fig. 1). These rocks are poorly Transactions on Ecology and the Environment vol 67,