Dimech Adrien, Isabelle Anne, Sylvain Karine, Liu Chong, Cheng LiZhen, Bussière Bruno, Chouteau Michel, Fabien-Ouellet Gabriel, Bérubé Charles, Wilkinson Paul, Meldrum Philip, Chambers Jonathan
Université du Québec en Abitibi-Témiscamingue (UQAT), Rouyn Noranda, QC, J9X 5E4, Canada.
Research Institute of Mines and Environment (RIME), Montréal, QC, Canada.
Sci Rep. 2023 Nov 27;13(1):20922. doi: 10.1038/s41598-023-48100-w.
Accurate and large-scale assessment of volumetric water content (VWC) plays a critical role in mining waste monitoring to mitigate potential geotechnical and environmental risks. In recent years, time-lapse electrical resistivity tomography (TL-ERT) has emerged as a promising monitoring approach that can be used in combination with traditional invasive and point-measurements techniques to estimate VWC in mine tailings. Moreover, the bulk electrical conductivity (EC) imaged using TL-ERT can be converted into VWC in the field using petrophysical relationships calibrated in the laboratory. This study is the first to assess the scale effect on the accuracy of ERT-predicted VWC in tailings. Simultaneous and co-located monitoring of bulk EC and VWC are carried out in tailings at five different scales, in the laboratory and in the field. The hydrogeophysical datasets are used to calibrate a petrophysical model used to predict VWC from TL-ERT data. Overall, the accuracy of ERT-predicted VWC is [Formula: see text], and the petrophysical models determined at sample-scale in the laboratory remain valid at larger scales. Notably, the impact of temperature and pore water EC evolution plays a major role in VWC predictions at the field scale (tenfold reduction of accuracy) and, therefore, must be properly taken into account during the TL-ERT data processing using complementary hydrogeological sensors. Based on these results, we suggest that future studies using TL-ERT to predict VWC in mine tailings could use sample-scale laboratory apparatus similar to the electrical resistivity Tempe cell presented here to calibrate petrophysical models and carefully upscale them to field applications.
准确且大规模地评估体积含水量（VWC）在采矿废弃物监测中对于减轻潜在的岩土工程和环境风险起着关键作用。近年来，时移电阻率层析成像（TL - ERT）已成为一种有前景的监测方法，可与传统的侵入式和点测量技术结合使用，以估算尾矿中的VWC。此外，利用TL - ERT成像的体积电导率（EC）可在现场通过实验室校准的岩石物理关系转换为VWC。本研究首次评估了尺度效应对尾矿中ERT预测VWC准确性的影响。在实验室和现场，对五个不同尺度的尾矿同时进行了体积EC和VWC的共定位监测。水文地球物理数据集用于校准一个用于从TL - ERT数据预测VWC的岩石物理模型。总体而言，ERT预测VWC的准确率为[公式：见原文]，并且在实验室样本尺度确定的岩石物理模型在更大尺度上仍然有效。值得注意的是，温度和孔隙水EC演化的影响在现场尺度的VWC预测中起主要作用（准确率降低十倍），因此，在使用互补水文地质传感器进行TL - ERT数据处理时必须适当考虑。基于这些结果，我们建议未来使用TL - ERT预测尾矿中VWC的研究可以使用类似于本文介绍的电阻率坦佩电池的样本尺度实验室设备来校准岩石物理模型，并谨慎地将其扩展到现场应用。
