Water-resource management has become a major global issue in a world threatened by climate change. High-resolution geophysical methods may be of valuable help in monitoring the water masses, both in space and time. Passive seismic interferometry takes advantage of ambient seismic noise to recover the variations in seismic wave velocity induced by changes in groundwater. We present hereafter the time and space monitoring of an hydraulic dome artificially formed to prevent biological and chemical pollutants from entering the exploitation field of Crépieux-Charmy (Lyon, France). We use a dense seismic network to passively monitor the water table changes induced by infilling of an infiltration basin at the water supply facility for the two million inhabitants of the Lyon Metropolis (France). We assess the hourly seismic velocity variations over 19 days, during which two filling and drainage cycles were performed. The use of a dense three-component seismic network allows fine characterization of the seismic wavefield, and offers the possibility to include the analysis of 4,851 raypaths in a robust inversion algorithm based on ray theory. The velocity variations are mapped with high resolution. They are directly related to the water table variations and to residual water saturation changes within the unsaturated zone. This seismic experiment highlights the three-dimensional (3D) implementation and evolution of a hydraulic dome under the infiltration basin. This dynamic information helps in the understanding and modeling of water flows between the water table and a river, which represents a fundamental issue for discussions on the effectiveness of the barrier.

中文翻译：

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从密集地震噪声采集中对受控地下水位变化进行高分辨率监测

在受气候变化威胁的世界中，水资源管理已成为一个重大的全球性问题。高分辨率地球物理方法可能有助于在空间和时间上监测水团。无源地震干涉测量利用环境地震噪声来恢复由地下水变化引起的地震波速变化。此后，我们将介绍对人工形成的液压穹顶的时空监测，以防止生物和化学污染物进入 Crépieux-Charmy（法国里昂）的开采领域。我们使用一个密集的地震网络来被动地监测由于里昂大都会（法国）200 万居民的供水设施中的一个渗透盆地填充而引起的地下水位变化。我们评估了 19 天内的每小时地震速度变化，在此期间进行了两个填充和排水循环。使用密集的三分量地震网络可以对地震波场进行精细表征，并提供了在基于射线理论的稳健反演算法中包括对 4,851 条射线路径的分析的可能性。以高分辨率映射速度变化。它们与地下水位变化和非饱和带内的残余水饱和度变化直接相关。该地震实验突出了渗透盆地下水力圆顶的三维 (3D) 实施和演变。这种动态信息有助于理解和模拟地下水位和河流之间的水流，