Study of the Agricultural Land Salinization by Subsurface Geophysical Methods in the Merdjadja Palm Grove Touggourt Region (Algeria)

The present work is devoted to applying geophysical methods to study the agricultural land salinization in a small palm grove in the Touggourt region located northeast of the Algerian Sahara. Several causes have made this region favorable to the accumulation of salts at the surface and at depth, such as its tectonics, low altitude, geomorphology, the direction of its water flow, and lithology, which are added anthropological practices that accentuate the phenomenon. The study began with an electromagnetic survey, whose results showed the presence of a conductive anomaly with an N–S direction occupying most of the western part of the palm grove. An electrical survey was then carried out to identify this anomaly, and several Schlumberger soundings were conducted. The processing and interpretation of the electrical resistivity data confirmed the high mineralization of the groundwater and the contact between the shallow water table and the Mio-Pliocene water table used for irrigation, thus explaining the poor physicochemical quality of the water in the latter.