Time-lapse electrical resistivity tomography to monitor moisture content in a laboratory compacted soil dam

Abstract

The use of dams in the context of mining and energy production is well established and adopted. However, the recent failures of these structures highlight the imperative need for improvements in monitoring in order to provide safe storage of materials in order to avoid environmental disasters. Tailings, laden with hazardous substances, pose significant environmental risks if managed incorrectly. Although dams perform vital functions in flood control, electricity generation and water supply, to ensure their safety it is necessary to continuously monitor soil moisture and water flow lines within the dam body. Geophysical techniques, particularly electrical resistivity tomography, provide valuable information on soil saturation variations, which is crucial for preventing structural failures. This research presents a geoelectric monitoring system applied to a laboratory model of a compacted soil dam, using electrical resistivity tomography and moisture sensors for six days. The analysis of electrical resistivity variations, complemented by photographic evidence, highlights the sensitivity of the method to subtle changes in soil saturation. These approaches increase dam safety by offering early detection and intervention mechanisms, which are crucial for mitigating environmental risks and safeguarding society’s interests.