Application of electrical resistivity in groundwater exploration in cyprus.

A number of geophysical methods have been used in groundwater exploration in Cyprus. Of these, electrical resistivity has found the widest application in the investigation of the mostly unconsolidated extensive aquifers of the Mesaoria Plain and the alluvial aquifers of the rivers draining the Troodos massif. Special emphasis has been given in this study on the detailed investigation by means of electrical resistivity of the aquifers of Western Mesaoria, Central Mesaoria and the three main Paphos rivers of Dhiarizos, Xeros and Ezusa where the nature of the deposits and the scarcity of exposures diminish the effectiveness of conventional hydrogeological methods. Existing hydrogeological information and specially conducted resistivity measurements of the magnitude and extent of lateral and orientational resistivity variations indicate that conditions in Western Mesaoria, the Paphos rivers and the larger part of Central Mesaoria are on the main suitable for the application of the electrical sounding technique. Over 120 correlation soundings measured in these areas show close correspondence between hydrogeological and electrical layers and enable the establishment of working geoelectrical models according to which the rest of the 904 soundings have been interpreted. In Western Mesaoria subsurface conditions are fairly simple and laterally persistent and two subaquifers to the Western Mesaoria Upper Aquifer are indicated by the electrical and hydrogeological results. In Central Mesaoria subsurface conditions are more variable while groundwater salinity variations complicate the picture. Interpretation of sounding measurements has been based on several geoelectrical models. In the Paphos rivers subsurface conditions are simple and the basic geoelectrical model assumes the presence of two alluvial layers with different physical properties. Aquifer geometry and configuration are accurately defined by the electrical-hydrogeological results. The electrical properties of the aquifers and associated rocks are derived while aquifer potential and hydraulic transmissivity appear to be related directly to the aquifer transverse resistance