The small islands in the Mediterranean Sea suffer water shortages, aggravated by pressure from tourism during the dry season. Many are affected by the intense and increasing human water demand and ...the harsh climatic and geographic nature of the island terrain. The present study, carried out on the island of Favignana, Egadi Archipelago (southern Italy), evaluates the regime of recharge to the subsurface, and hypothesizes a solution for identifying the areas where groundwater is most abundant, as well as the best management options for human use. By means of hydrological measurements and chemical analyses, a specific location has been identified in the eastern sector of the island where groundwater has optimal quality and the water table is at a depth of only a few metres. In other areas of the island the groundwater is more saline, due to seawater intrusion, and it is present only at greater depths. The residents of the island have in the past lived harmoniously with the climatic and hydrological regime of the island, and have shown good ability to manage the groundwater resources, fed by the limited precipitation that comes in winter, using it as a supplement to the drinking water supply that comes from Trapani (mainland Sicily) by a submarine pipeline and by tanker. Optimized management of the groundwater resources could reduce the volume of freshwater transferred from the mainland.
In the present work, preliminary results are reported from an ongoing research study aimed at developing an improved prediction model to estimate the sediment yield in Italian ungauged river basins. ...The statistical correlations between a set of hydro-geomorphometric parameters and suspended sediment yield (SSY) data from 30 Italian rivers were investigated. The main question is whether such variables are helpful to explain the behavior of fluvial systems in the sediment delivery process. To this aim, a broad set of variables, simply derived from digital cartographic sources and available data records, was utilized in order to take into account all the possible features and processes having some influence on sediment production and conveyance. A stepwise regression analysis pointed out that, among all possibilities, the catchment elevation range (Hr), the density of stream hierarchical anomaly (Da), and the stream channel slope ratio (ΔSs) are significantly linked to the SSY. The derived linear regression model equation was proven to be satisfactory (r2-adjusted = 0.72; F-significance = 5.7 × 10−8; ME = 0.61), however, the percentage standard error (40%) implies that the model is still affected by some uncertainties. These can be justified, on one hand, by the wide variance and, on the other hand, by the quality of the observed SSY data. Reducing these uncertainties will be the effort in the follow-up of the research.
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