A customized resistivity system for monitoring saturation and seepage in earthen levees: installation and validation

Abstract

This work is based on the assumption that a resistivity meter can effectively monitor water saturation in earth levees and can be used as a warning system when saturation exceeds the expected seasonal maxima. We performed time-lapse ERT measurements to assess the capability of this method to detect areas where seepage is critical. These measurements were also very useful to design a prototype monitoring system with remarkable savings by customizing the specifications according to field observations. The prototype consists of a remotely controlled low-power resistivity meter with a spread of 48 stainless steel 20 × 20 cm plate electrodes buried at half-meter depth. We deployed the newly-designed permanent monitoring system on a critical levee segment. A weather station and an ultrasonic water level sensor were also installed in order to analyse the correlation of resistivity with temperature, rainfalls and water level seasonal variations.

Keywords

• geophysical monitoring
• permanent geoelectrical monitoring
• time lapse dc-resistivity
• embankment seepage
• embankment monitoring
• levee stability
• hydrogeological risk prevention
• flood prevention