Determination Water Level by Electrical Resistivity and Comparing Results with Drilled Well in Al-Naharwan, Baghdad

Abstract

The 2D electrical resistivity imaging survey was done in Al-Naharawan area within Baghdad city for unknown subsurface to give a best location for digging a new well. Electrical resistivity imaging survey is implemented for along four lines that are 120 m long and all have 1m electrode separation. Measurements done with wenner-Schlumberger array and interpreted data by using RES2DINV program. The results for drilling the well at electrodes 62 and 63 in line 1 showed exactly corresponds to the lithological order of the well Fadhel Abass. Electrical resistivity imaging results showed high and low resistivity values, although they both contain clay, which corresponds to variances in water content. One Groundwater sample was taken from the new well and analyzed chemically to determine the concentration of the major ions. water analysis shows high TDS, electrical conductivity, and most parameters affecting human life out of permissible limits, so it is not suitable for human drinking. SAR =21.695, RSC=-474, which indicates the risk from sodium is improbable and lies within permissible ranges. PI% within Class II, meaning the water quality is good for irrigation. The findings indicated that the 2D imaging method is an effective and powerful enough tool for identifying new well with water table and detecting subsurface.