Efeito Da Profundidade Dos Eletrodos Em Levantamentos De Eletrorresistividade

The influence of electrode depths in electroresistivity<br>survey is studied. Generally, the investigators don’t care<br>about this detail but it can introduce significant departures<br>on the apparent resistivity values obtained with<br>small electrode spacings. To check the influences, theoretical<br>analysis is performed using simulated vertical<br>electrical sounding with undergrounded Wenner array.<br>Field data using Schlumberger array are collected to<br>demonstrate the existence of such effects. Computed<br>apparent resistivity values obtained with the same field<br>array parameters, separations and depths, are successfully<br>fitted to the field data, and a horizontally layered<br>model is obtained. The studies with two layer models,<br>shown that the effects of undergrounded electrodes are<br>more expressivewhen the second layer is more conductive<br>than the first one. Ambiguities arise in the reversed situations.