Dc-Resistivity Multi-Electrode Profiling In Hydrogeological Investigations: A Comparative Study Of The Pulled Array Continuous Electrical Sounding Method And A Multi-Electrode Method With Fixed Electrodes

In environmental and engineering problems 2D DC-resistivity data sets are now commonly<br>collected using computerised data acquisition systems of which several are commercially<br>available. At least two different approaches have been followed in the design of computerised<br>acquisition systems, one using many fixed electrodes (e.g. Griffiths and Turnbull 1985, van<br>Overmeeren and Ritsema 1988, Dahlin 1996) and another using electrode configurations<br>that are moved while the measurements are carried out (e.g. Hesse et al. 1986, Panissod et<br>al. 1997, Sorensen 1996, Sorensen and Sorensen 1995).<br>One system using moving electrodes, developed for the purpose of large-scale near-surface<br>mapping, is the Pulled Array Continuous Electrical Profiling, PACEP, system, (Sorensen<br>1996) where measurements are carried out continuously and simultaneously in 3 electrode<br>configurations. To enhance the vertical resolution the method is upgraded to carry out<br>measurements in 8 electrode configurations simultaneously, the Pulled Array Continuous<br>Electrical Sounding, PACES, system (Sorensen and Sorensen 1995).<br>In this paper data measured with the PACES method is compared with data measured<br>with a multi-electrode system with fixed electrodes. The ABEM Lund Imaging System will<br>represent the fixed electrode systems (Dahlin 1996).