SUB-SOIL CORROSIVITY ASSESSMENT USING RESISTIVITY MEASUREMENTS IN KULA ISLAND, RIVERS STATE, NIGERIA

Abstract

Sub-soil corrosivity evaluation using resistivity measurements in Kula Island and its environs,
Rivers State, Nigeria, was carried out. The Wenner array configuration of electrical sounding at
test points BH1, BH2, BH3, BH4, BH5, BH6, BH7, BH8, BH9, & BH10 was adopted. Soil resistivity
influences the corrosion of metals installed underground and can serve as an indicator of soil
corrosiveness. From corrosion engineering perspective, the lower the resistivity, the higher the
corrosivity and vice versa. The data for the evaluation were acquired between 25 th October and 5 th
November 2019, under fairly favorable weather conditions. The results revealed variations in
distribution of the subsurface resistivity and corrosivity with depth. The evaluation within the area
of study revealed a resistivity range from a low value of 1.07 Ωm at 6 m from test point BH10 to a
high value of 136.9 Ωm at 1.5 m from test point BH5. By classification, the corrosivity of the
subsoil within the study area range from corrosive to moderate to very high. The results of the
study averagely indicate that most of the soil within the environment is mildly corrosive in nature.
The result is a suggestive of a non-violent threat to any work that has to do with subsoil corrosion
effect in the area.