Développement d'un système de mesures électriques automatisé pour aider à la surveillance des ouvrages de restauration de sites miniers

与矿物开采有关的环境问题主要与风化矿物组合暴露于空气和水流时的化学不稳定性有关。已经制定和应用了不同的尾矿库和废石堆管理和回收战略，通过限制水流和氧气的渗透来防止酸性矿山废水的产生。在尾矿库和废石桩顶部建造覆盖层是一种容易实施且成本相对较低的复垦策略。然而，这些覆盖层受到侵蚀、冻融效应、植被活动、极端天气事件和气候变化的影响。因此，随着时间的推移评估和监测它们的表现是很重要的。目前进行监测的是传统的水文地质仪器，如含水率和吸力探头、压力计和溶渗计；这就不太适合大面积（达几百公顷）的监测。事实上，这些测量的调查范围是有限的（探测器周围的几立方分米）。我们建议开发和应用一个电子成像系统来评估覆盖层的性能在加拿大的矿区复垦的背景下。自动化测量将用于重建整整一年的水含量分布。提出的大规模电成像还旨在确定整个尾矿库和废石堆的最佳覆盖层几何形状，以供未来设计。

The environmental issues associated with mineral exploitation are mostly associated with the chemical instability of weathering mineral assemblages when they are exposed to air and water flows. Different tailing ponds and waste rock piles management and reclamation strategies have been developed and applied to prevent the generation of acid mine drainage, by limiting the water flow and the penetration of the oxygen. The construction of cover layers on the top of tailings ponds and waste rock piles is one of the most promising reclamation strategies since it is easy to implement and relatively inexpensive. However, these cover layers are subject to erosion, freeze and thaw effects, vegetation action, extreme weather events and climate changes. It is therefore important to evaluate and to monitor their performance over time. The monitoring is currently carried out with traditional hydrogeological instruments, such as water content and suction probes, piezometers and lysimeters; which is not very suitable for the monitoring of large areas (up to several hundred hectares). Indeed, the measurements have a limited volume of investigation (a few cubic decimeters around the probes). We propose to develop and apply an electrical imaging system to evaluate the performance of cover layers in the context of mining site reclamation in Canada. Automatized measurements will be used to reconstruct the water content distribution continuously for a full year. The proposed large-scale electrical imaging also aims to identify the best cover layer geometry over the entire tailings pond and for waste rock piles for future design.