Présentations Colloques

Oral Presentation
Session 8.02: Groundwater Development and Protection in Coastal and Volcanic Environments with Complex Geological Structures
Tulipano Luigi
Leros island (Greece)- how to exploit the hidden water
This paper presents an original technical proposal aimed to satisfy water demand in Leros Island, belonging to Dodecanese archipelago, in Egeo sea. The geology of Leros island is very complex and its interpretation is very difficult because of the effects a very intense tectonic activity. The morphology is characterized by impressive fault scarps. The age of the outcropping formations varies from 300 million of years to the present. The hydrogeological sequence outcropping in Leros island is made, starting from the younger formations, by beach deposits, with high permeability, overlaying Molassic sediments, very impervious, from the hydraulic point of view, and thick carbonate formations, characterized by very high permeability, which overlay a thick clayey, very impervious, deposit, Carbonate formations are very good aquifers due to the high permeability degree and the high storage capacity. When precipitations overpass Molassic sediments The vertical path of infiltrating water, percolation, stops where an impervious layer is encountered and saturated zone is formed- then the sub horizontal flow (filtration) takes place carrying groundwater to springs, which, in Leros, are mainly directly under the sea level, or through coastal (sub aerial and submarine) springs. This technical proposal deals with a catchment work design aimed to the exploitation of an hidden groundwater resource, stored in two areas the Klidi and the Skoumbarda ones, where carbonate formations, characterized by very large cavities, can store very important quantities of water. Unfortunately usually these groundwater reach the sea, after having mixed themselves with seawater and becoming unfit for human uses. This technical purpose comes from the discovering by innovative investigation tools where these storage cavities are placed and try to catch groundwater before their mixing with seawater.**
United Kingdom