Hydraulic Aquifer Characteristics Determined From Resistivity Sounding Parameters Using Empirical Formulae And Geostatistical Techniques

Geohydrological data obtained through pump tests, are typically scarce and expensive.<br>Geophysical observations on the other hand are less expensive and can be obtained more<br>readily. Where geophysical observations can be shown to correlate with geohydrological<br>properties the potential exists for augmenting a sparse geohydrological data set with<br>predictions based on geophysical observations.<br>This paper describes the results obtained with the direct current resistivity method, using<br>the Vertical Electrical Sounding (VES) technique in defining certain aquifer characteristics,<br>i.e. transmissivity and porosity. In the past many attempts have been made to establish<br>empirical hydrogeophysical relationships, without understanding the physical principles of<br>the problem completely.<br>The complicated relationship that exists between formation geometrical factors, and the<br>governing ground water and current flow equations, resulted in the use of geostatistics to<br>interpolate hydraulic values to unknown points in the aquifer, using direct current<br>resistivity parameters.<br>In this study results from the use of empirical methods, geostatistical methods like kriging<br>and co-kriging are compared. Advantages and disadvantages in applying these<br>geostatistical techniques are discussed.