Data for: Geo-Resistivity Data Set for Groundwater Aquifer Exploration in the Basement Complex Terrain of North-Central Nigeria
Description
The raw data are the electrical resistivities acquired by Vertical Electrical Sounding (VES) method. They are stored in file vesdata.mat and vesdata.cvs. The data represent changes in the resistivities of rocks and soil materials measured at various depths equivalent to AB/2. Where AB/2, the half of the current electrodes separation ranges from 1 to 100 m. The data acquisition equipment comprised SAS 3000 ABEM Resistivity Meter, four metallic electrodes, electrical cables, measuring tapes, portable Geographic Positioning System (GPS) device, hammer, battery, measuring tapes, a source of direct current (battery) and other accessories. The data is suitable for charactering subsurface rock layer/units and the features that are suitable for groundwater accumulation and mineral exploration. The first column of the MATLAB file contains the values of AB/2, while the rest 85 columns (2 to 86) contain the raw resistivity data acquired at the respective 85 locations. The same arrangement applies to the .CVS file. Appendix II is an excel file. It consists of geo-referencing data (the longitude and latitude), measured at every VES point using portable GPS device. The geo-referencing data are useful for locating the exact point where the electrical resistivity data were acquired. Geo-referencing data are important for field validation of the experiment and for identifying other geophysical data (e.g. Seismic or Ground Penetrating Radar) from the same area, that can be usefully combined in the future, for a better evaluation of the subsurface. Supplementary files III(a) and III(b) are Images data. Stored in .tiff format. These images are the plots of the processed data showing some groundwater aquifer parameters inverted from the raw data. Appendix III(a) is the thickness map of the weathered aquifers, while appendix III(b) is the estimated depths to the bottom of boreholes in the different parts of area. The image data provided useful insights to the hydrogeology of the study area. The data set is precise, repeated experiments at some locations within the area produced similar raw data sets and VES curves. The RMS error between the field data curve and the computer models curves is generally less than 10 percent.