Detection and imaging of piping sinkholes by integrated geophysical methods
Detection and imaging of piping sinkholes by integrated geophysical methods
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DOI：
10.3997/1873-0604.2013051
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发表时间：
2014-06
影响因子：
1.6
通讯作者：
E. Cardarelli;M. Cercato;G. D. Donno;G. D. Filippo
中科院分区：
文献类型：
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作者：
E. Cardarelli;M. Cercato;G. D. Donno;G. D. Filippo
在钙质基岩上有厚覆盖层的情况下，管道天坑可能自然形成。它们的探测和成像对地球物理方法来说是一项具有挑战性的任务，不仅因为需要分辨率和穿透深度，而且因为在这些地质复杂的地区，将地球物理异常推测为地质特征可能会产生重大缺陷。来自不同地球物理方法的数据整合对于消除这些解释歧义至关重要，这些解释歧义是由大的近地表梯度和土壤性质的非均质以及地下水位的振荡和异常水循环引起的。我们提出了一种调查程序，包括电阻率层析成像（ERT）、地震折射层析成像（SRT）和自电位（SP）测量的顺序应用和综合解释，用于定位和监测管道天坑，并应用于意大利中部的一个站点。这种方法是解决方案和成本效益之间的折衷，其设计目的是使私人最终用户在经济上负担得起。在复杂的地质情况下，通常不可能评价一种地球物理技术在分辨率、成本效益和诊断能力方面优于所有其他技术。不同地球物理方法的独立信息是评价管道陷落洞位置和随时间发展的关键。拟议的调查程序的应用使我们能够单独确定一个小区域，以形成一个管道天坑。地球物理结果在地球物理测量执行大约一年后得到证实，因为该地点显示出一个管道天坑的表面证据，形成了一个小池塘，充满了含硫水和从下面冒出来的气体。
Piping sinkholes may naturally develop in the case of a thick overburden overlying calcareous bedrock. Their detection and imaging is a challenging task for geophysical methods, not only because of the required resolution and depth of penetration, but also because major pitfalls may arise, in such geologically complex areas, from the speculative interpretation of geophysical anomalies as geological features. Data integration from different geophysical methods is essential to remove these interpretation ambiguities, caused by large near-surface gradients and heterogeneities in the soil properties, as well as by oscillations of the water table and anomalous water circulation. We present an investigation procedure consisting of the sequential application and integrated interpretation of Electrical Resistivity Tomography (ERT), Seismic Refraction Tomography (SRT) and Self Potential (SP) measurements for locating and monitoring piping sinkholes with application to a site in Central Italy. This approach is a compromise between resolution and cost-effectiveness, and it is designed to be economically affordable by the private end user. In complex geological scenarios, it is usually not possible to rate a single geophysical technique as superior to all the others in terms of resolution, cost-effectiveness and diagnostic capability. The independent information coming from the different geophysical methods is the key to removing interpretation ambiguity when evaluating the position and the development over time of the piping sinkholes. The application of the proposed investigation procedure allowed us to individuate a small area subject to the formation of a piping sinkhole. The geophysical results were confirmed about one year after the execution of the geophysical measurements, as the site exhibited surface evidence of a piping sinkhole, with the formation of a small pond filled with sulphurous water and gases coming from below.