IMAGING SEAWATER INTRUSION IN COASTAL ZONE OF KAVALA (N. GREECE) WITH ELECTRICAL RESISTIVITY TOMOGRAPHY

Abstract

The needs for water supply in the western coastal zone of Kavala (N. Greece) have been rapidly increased during the last decades because of the high tourist and agricultural development. This resulted to a number of wells that drilled along the coastline. During summer period, when human and irrigation consumptions are maximized, phenomena of groundwater salinization are observed. Although restrictions to new drillings have been taken, salinization in some aquatic systems of the area tends to become a major environmental and economical issue. The only available information till now was a timeseries of groundwater electrical conductivity measurements, in some of the wells of the area. This information is useful but not adequate for the study of the salt intrusion mechanism. Geophysical investigation was carried out and electrical resistivity tomography (ERT) was chosen as the most appropriate technique for the case. The geophysical survey was set in a site between the coastline and an existing borehole. The 2D ERT profiles gave a clear image of geoelectrical heterogeneities, associated with seawater intrusion in the coastal aquifers, contributing to future measures towards a rational management of ground water resources in the area.