GEOFCAN : actes du 2ème colloque de géophysique des sols et des formations superficielles : résumés étendus

The EM-38 is a useful instrument for making rapid field identification and mapping of soil salinity. Interpretation of measurements in terms of meaningful parameters of soil salinity is difficult, mainly due to the non-uniform response distribution with depth. The aim of this paper is to propose a method leading to the intepretation of the salinity maps in terms of soil salinity by calculating (i) the areas of the soil volumes defined by salinity mapping, (ii) the salt content of these volumes using the calibration of EM-38. Applied to the acid and saline soils of a southern Senegal bottomland, the results show that the soils annually desalinized. However, this desalinization is mainly dependant on annual rainfall. The salt losses at the dam outlet are partly compensated by a groundwater connected to highly saline seawater. (Résumé d'auteur