Keywords: electrical resistivity, residual resistivity, cavity detection, CRSP array In some cases, anomalies detected by the RR-based images were hidden in the conventional method. The results showed that the anomalous zones are better highlighted in the RR-based inversion images in comparison with the conventional inversion images. A case study was carried out in a karstic area in Zarrinabad, Lorestan Province, western Iran, to detect the location and geometry of probable cavities by conventional resistivity inversion and RR-based inversion. The RR technique was applied to several synthetic models to compare the conventional resistivity inversion of each model with its RR-based inversion. To determine the background resistivity, the data acquired from electrical resistivity measurements along a given survey line is evaluated, and then an equation is fitted to the data corresponding to a chosen measurement station as a function of current electrode spacing (or array length). We define RR as measured resistivity minus background resistivity. This article is devoted to the introduction of a new technique of electrical resistivity data processing called residual resistivity (RR). Anomaly enhancement in 2D electrical resistivity imaging method using a residual resistivity techniqueĪmirkabir University of Technology, Tehran, Iran

Res2dinv apparent resistivity graph