An Iterative 3D Correction plus 2D Inversion Procedure to Remove 3D Effects from 2D ERT Data along Embankments.

Area of Science:

• Geophysics
• Geotechnical Engineering
• Environmental Monitoring

Background:

• 2D electrical resistivity tomography (ERT) monitoring of embankments is challenged by 3D geometric effects.
• These distortions significantly impact the accuracy of monitoring data, crucial for hydrogeological risk assessment.

Purpose of the Study:

• To develop and validate an iterative algorithm for correcting 3D effects in 2D ERT monitoring data of embankment structures.
• To assess the algorithm's performance using synthetic and real-world data from a river levee.

Main Methods:

• An iterative 3D correction plus 2D inversion procedure was adopted.
• Synthetic data were generated using Res2dmod and Res3dmod for a modeled embankment.
• The algorithm was tested on real ERT data from a levee monitoring system after dry and rainy periods.

Main Results:

• Synthetic tests demonstrated rapid convergence of the proposed algorithm for 3D effect correction, even without prior information.
• Real data analysis revealed that 3D effects can cause substantial ±50% changes in inverted resistivity images.
• The algorithm effectively removed these critical artifacts, ensuring reliable data.

Conclusions:

• The developed algorithm provides a rapid and validated solution for removing 3D effects in 2D ERT monitoring.
• Accurate resistivity images are essential for generating reliable water content maps for hydrogeological risk mitigation.
• The method supports near-real-time data processing for effective embankment monitoring.