In-field Assessment of Soil Salinity and Water Content with Electrical Geophysics

Abstract

Irrigated agricultural lands in arid and semi-arid areas are particularly vulnerable to climate change and subjected to secondary salinization. Detailed maps of the subsurface are necessary to manage and ameliorate salinity but difficult to obtain, as salinity is dynamic and highly spatially variable. Our group tested several on-ground geophysical instruments and geostatistical approaches for studying soil and groundwater salinity around the world for the last 20 years. Here we present an overview for updated methodologies of electrical geophysical methods (galvanic contact and multi-frequency electromagnetic induction) measuring soil electrical conductivity or resistivity in-situ from the surface down to the depth of 10–20 m to estimate soil salinity, water content, and depth to groundwater table in arid and humid environments both in rural and urban settings.