Shallow-landslide susceptibility in the Costa Viola mountain ridge (southern Calabria,Italy) with considerations on the role of causal factors

The “Costa Viola” mountain ridge (southern Calabria), in the sector between Bagnara Calabra and Scilla, is particularly exposed to geo-hydrological risk conditions. The study area has repeatedly been affected by slope instability events in the last decades, mainly related to debris slides, rock falls and debris flows. These types of slope movements are among the most destructive and dangerous for people and infrastructures, and are characterized by abrupt onset and extremely rapid movements. Susceptibility evaluations to shallow landslides have been performed by only focusing on source activation. A logistic regression approach has been applied to estimating the presence/absence of sources in terms of probability, on the basis of linear statistical relationships with a set of territorial variables. An inventory map of 181 sources, obtained from interpretation of air photographs taken in 1954–1955, has been used as training set, and another map of 81 sources, extracted from 1990 to 1991 photographs, has been adopted for validation purposes. An initial set of 12 territorial variables (i.e. lithology, land use, soil sand percentage, elevation, slope angle, aspect, across-slope and down-slope curvatures, topographic wetness index, distance to road, distance to fault and index of daily rainfall) has been considered. The adopted regression procedure consists of the following steps: (1) parameterization of the independent variables, (2) sampling, (3) calibration, (4) application and (5) evaluation of the forecasting capability. The “best set” of variables could be identified by iteratively excluding one variable at a time, and comparing the ROC results. Through a sensitivity analysis, the role of the considered factors in predisposing shallow slope failures in the study area has been evaluated. The results obtained for the Costa Viola mountain ridge can be considered acceptable, as 98.1 % of the cells are correctly classified. According to the susceptibility map, the village of Scilla and its surroundings fall in the highest susceptibility class.     

Small-scale landfills: impacts on groundwater and soil

In Brazil, the large quantities of solid waste produced are out of step with public policies, technological developments, and government budgets for the division. In small municipalities, the common lack of technological knowledge and financial conditions for suitable waste disposal has resulted in a large number of illegal dumps. Therefore, small sanitary landfill facilities are working with simplified operations focusing on cost reduction and meeting the economic and technological standards of the city without endangering the environment or public health. Currently, this activity is regulated at a federal level although there is some uncertainty regarding the risk of soil and aquifer contamination as theses facilities do not employ liners. Thus, this work evaluates a small landfill to identify changes in soil and groundwater using geotechnical parameters, monitoring wells, and geophysical tests performed by electrical profiling. It is verified that based on current conditions, no contaminants have migrated via underground water aquifers, and overall no significant changes have occurred in the soil. It is concluded that, despite its simplicity, the method investigated is a viable alternative for the final disposal of municipal solid waste from small cities, especially in developing countries.     

The MED-SUV virtual research environment for enabling the GEO Geohazard supersites in Italy

This paper presents the Virtual Research Environment (VRE) enabling two European GEO Geohazard Supersites in Italy. According to GEO (Group on Earth Observation) vision, Geohazard Supersites provide access to spaceborne and in-situ geophysical data and models for selected sites prone to natural hazards –noticeably, earthquakes and volcano eruptions. The VRE was implemented in the framework of the Mediterranean Supersite Volcanoes (MED-SUV) project, funded by the European Commission. MED-SUV realized one of the European supersite demonstrators covering the two Permanent Supersites selected in Italy: Mt. Etna and Campi Flegrei/Vesuvius. The MED-SUV VRE provides advanced services for heterogeneous data and information management and sharing. MED-SUV started identifying the main supersite requirements including: the interoperability with existing data/information supply systems, the support of policy-based access control, the access to processing capabilities provided by external platforms, the management resources for publishing and sharing new products, the integration with significant global systems such as GEOSS and EPOS. MED-SUV adopted a System of Systems (SoS) approach to address interoperability with the identified heterogeneous systems supplying data and information. The SoS approach is based on a brokering architecture, where a specialized component (i.e the MED-SUV Broker: MSB) connects the existing and next-coming data sources leaving them autonomous. MSB carries out all the necessary mediation and harmonization tasks exposing standard interfaces enabling the interconnection with external systems like GEOSS and EPOS. In addition, MSB is accessible via a JavaScript library implementing Web APIs to facilitate the development of Web and mobile applications.     

Continental evaporites and the search for evidence of life on Mars

Continental evaporites are deposits that originate from the evaporation of saline waters in the low areas of saline lakes from all continents, except Europe, and mainly consist of chloride, sulphate and potash minerals. In recent years, the discovery on the Martian surface of hydrated salt minerals, including sulphates and chlorides, interpreted as deriving from the desiccation of preexisting large bodies of water, such as lakes, has provided further convincing evidence of liquid water activity on the surface of Mars and, consequently, it has reinforced the plausibility of finding life. Because evaporites require short‐term aqueous processes for their formation, they can trap and preserve over geologic times a biological record made up of halophilic extremophiles—such as microalgae, bacteria, and their remains—that recent research on Earth has shown to be characterized by unexpectedly high biodiversity. This record may consist of varying types of fossils, including morphological fossils, chemofossils and biominerals. As a consequence, continental evaporite environments and their saline deposits are now a primary target for the near future astrobiology missions devoted to the search for fossil Martian life. Lacustrine evaporite deposits and minerals have, therefore, been identified as primary targets for the NASA–ESA joint programme of the Mars sample return, planned for the end of the current decade. Copyright © 2011 John Wiley & Sons, Ltd.