Resistivity Monitoring

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Resistivity Monitoring

The monitoring and maintenance of earthen structures, including levees, impoundments, dams, and embankments, is an ongoing and critical process to ensure the integrity of these structures, and prevent failure and the potential consequences. Resistivity monitoring provides a uniquely broad, yet detailed, picture of seepage occurring through such earthen structures. We are asking that these structures hold back significant amounts of water or other waste materials and ensuring that they are operating safely is paramount. With a monitoring program that specifically includes resistivity, we can minimize risk to downstream structures by identifying potential points of weakness in these earthen structures or providing an early warning for changing conditions of existing seepage.

 

Resistivity monitoring can minimize risk to earthen structures by providing a greater understanding of seepage through levees, impoundments, dams, and embankments.

 

Close-up of a metal stake with an orange flag and black tubing, resembling an electrode for resistivity monitoring, placed in a rocky, arid landscape. The tubing stretches into the distance as part of an irrigation or construction setup. Hills and earth-moving equipment are visible in the blurred background.
 

A resistivity monitoring program involves making repeated measurements of resistivity over time. By observing a changing resistivity value, we can more accurately pinpoint issues related to stability, erosion, or assess possible conditions that give rise to inadvertent seepage. In some of our previous investigations, we have found water moving along old stream channels, weaknesses in pre-construction geology, and sand lenses and other buried structures that provided conduits for water to preferentially flow. When these data are then combined with site knowledge, borings, or other hydrological data, a more complete assessment can be made for conceptual model design.

 

 

Two side-by-side diagrams in the monitoring plot compare electrical resistivity in a section of land for June and September 2016. The June diagram shows baseline resistivity, whereas the September diagram illustrates percentage change. The key indicates various resistivity and conductivity values, highlighting time-lapse changes.
 

The advantage of the resistivity method, as is the case with most other geophysical methods, is its scalability to meet the desired resolution, coverage, and depth of investigation. By looking at the resistivity parameter over time, we can discern important features that provide detail regarding the movement of water internal to the structure. The advantage to using HGI to acquire these data is that we can design surveys that meet the demand of the project, from the small scale embankment to the large scale levee and everything in between. We also manufacture equipment specifically tailored for resistivity monitoring of the riskiest containment systems <<link to LDM somewhere within our sites>>.

 

hydroGEOPHYSICS is well suited to monitor your earthen structure, as we have applied our geophysical methodology to a large number of earthen structures over the past two decades. We can help assure that risk is minimized through the power of visualized knowledge.

 

Over the past decade, we have applied our geophysical methods on a number of earthen structures and we have gained an unprecedented wealth of knowledge about how each earthen dam may function. With this knowledge, hydroGEOPHYSICS can help you understand a newer level of your structure, help improve safety, and reduce risk.