Correlation of Soil Properties and Electrical Resistivity as an Indicator of Erosion Potential Using the Hole Erosion Test (HET)

Erodibility is defined as the resistance of soils and rocks to erosion. In recent years, several studies have been conducted on the correlation between erodibility and geotechnical properties of soil. However, erodibility and its relationship with geophysical properties, such as electrical resistivity, are still under investigation. Geophysical methods provide a non-destructive way to evaluate soils over large areas, so using them to evaluate erosion would save time and money. The following research aimed to test soil samples and develop possible correlations between soil erodibility and electrical resistivity. However, there are many geotechnical properties that influence soil erodibility and resistivity, therefore, in establishing these correlations the influences of plasticity index, dry density and moisture content were studied. A modified standard Hole Erosion Test system was built to determine the erosion rate index, which is a way of quantifying erodibility, while a Nilsson Model 400 resistance meter was used to determine electrical resistivity. The results showed that there is an existing correlation between resistivity and erodibility for the soils studied categorized as “very strong”, according to Pearson's linear correlation coefficient. This research gives rise to the possibility of elaborating a mathematical model that allows estimating the erosion rate index from the electrical resistivity of the soil.