Vertical electrical sounding technique for evaluating and characterizing weathered Neogene basaltic aquifer in Jbab area, Southern Syria

ABSTRACT

Vertical electrical sounding (VES) technique with Schlumberger array is used to characterize the subsurface basaltic aquifers in Jbab area, Southern Syria. The second indices of different Dar-Zarrouk (D-Z) parameters resulting from the one-dimensional (1D) quantitative interpretations of 18 VES points allow to characterize both the subsurface basaltic environment with depth and the weathered/fractured Neogene basalt aquifer in the study region. The anisotropy coefficient (λ) varies between 1.1 and 2.1 with an average of 1.40. The fracture porosity (φf) ranges from 0.016 to 0.40, with an average of 0.12, indicating different water saturation degrees within the weathered basaltic aquifer. The Neogene basaltic aquifer exists at a depth varying between 12.40 and 291.8 m, with an average of 66.22 m, its thickness varies between 32.3 and 244.4 m, with an average of 152.91 m. Its resistivity is between 12.53 and 53.40 Ω.m with an average of 30.63 Ω.m. The hydraulic conductivity (K) varies between 0.64 and 0.68 m/day, with an average of 0.66 m/day, while the transmissivity (T) ranges between 21.94 and 162.68 m2/day with an average of 101.16 m2/day.