Estimation of porosity and specific yield by application of geoelectrical method – A case study in western Iran

Vertical Electric Soundings (VESs) with a Schlumberger electrode configuration were recorded in the Mahidashat plain, Kermanshah province, located in the western part of Iran, in order to estimate the hydraulic parameters of the aquifer system. The geological formations surrounding the plain are mainly cretaceous limestones and plagioclases with regular layering of Miocene age. The northwestern part of plain is composed of red marls of Eocene age. In order to ascertain the subsurface geological framework the general distribution of resistivity response of the geological formations was obtained. Geoelectrical sections along a number of lines have been prepared. Probable lithological patterns from these sections have been identified. In the present study, an attempt to estimate porosity and specific yield from resistivity data has been made for alluvial aquifers in Mahidashat plain. The results indicated that the porosity varies from 0.18 to 0.66 and the average specific yield is 0.15. The estimated data are compared with field real data and their credibility was calculated by using the paired t-test method.