Use of geophysical methods for the demonstration of Karstic phenomena in southern Algeria: Guerraraarea (district of Ghardaïa. Algeria)

Abstract

Karst and pseudo-karst result from natural phenomena associated with the circulation of water through soluble geological environments, causing subsidence, sinkholes, cavities and collapses. During the last five years, Guerrara area (southern Algeria) was the subject of multidisciplinary studies to characterize the geological formations and assess the impact of their distribution on the movement of water surface and deep aquifers.

This study undertaken in three sites from the Guerrara area aims at the recognition and the characterization of underground voids (size, extension) by geophysical methods such as vertical electrical soundings and electrical tomography combined with 2D electromagnetic imaging ground penetrating radar GPR.

Keywords: Pseudo-karst, sinkholes, Collapses, Ground penetrating radar, Cavities