Search

Abstract: In this paper we analyze the main available data related to the geothermal system of Ischia Island, starting from the first geothermal exploration in 1939. Our aim is to define a conceptual model of the geothermal reservoir, according to geological, geochemical, geophysical and stratigraphic data. In recent times, the interest on geothermal exploitation for electricity generation in Italy is rapidly increasing and the Ischia Island is one of the main targets for future geothermal exploitation. Nowadays, one of the main economic resources of the island is the tourism, mainly driven by the famous thermal springs; so, it is crucial to study the possible interaction between geothermal exploitation and thermal spring activities. To this aim, we also analyze the possible disturbance on temperature and pressure in the shallow geothermal reservoir, due to the heat withdrawal for electric production related to small power plant size (1–5 MWe). Such analysis has been performed by using numerical simulations based on a well known thermofluid-dynamical code (TOUGH2®). Obtained results show that such geothermal exploitation generates a perturbation of temperature and pressure field which, however, is confined in a small volume around the well. At shallow level (0–100m) the exploitation does not produce any appreciable disturbance, and can be made compatible with thermal spring exploitation. Moreover, such results are crucial both for the evaluation of volcanological processes in the island and for the general assessment of geothermal resource sustainability. [Copyright &y& Elsevier]

Abstract: In this paper we present an approach for evaluating landslide susceptibility in seismic areas. It is known that earthquake-induced landslide susceptibility is related to several, often interplaying, factors. Nevertheless, an effective grade-2 zonation should be characterized by a good balance between simplicity, quickness and reliability. The GIS-based procedure we present employs only three factors that we believe are the most significant in this susceptibility assessment: the type of outcropping rocks/soils, the slope angle and the MCS intensity. The local annual precipitation, certainly an essential factor, is considered here as a parameter whose seasonal pattern is constant in time and space. Each of the three parameters is expressed as a Significance percentage and the resulting Seismic Landslide Susceptibility level of an area is given by the average of the significances of the first two factors multiplied by the significance of the third factor. The procedure was set and tested on the volcanic island of Ischia (southern Italy), which was affected by several historical earthquake-induced landslides. The results of this susceptibility zonation test at Ischia show a very good match between the distribution of the sources of historical landslides and the areas we identified as the most susceptible ones. [Copyright &y& Elsevier]