Application of the CSAMT method to groundwater exploration in a metropolitan environment
Application of the CSAMT method to groundwater exploration in a metropolitan environment
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CSAMT方法在都市环境地下水勘探中的应用
DOI：
10.1190/geo2012-0533.1
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发表时间：
2013-09-01
期刊：
影响因子：
3.3
通讯作者：
An, Zhiguo
中科院分区：
文献类型：
--
作者：
Fu, Changmin;Di, Qingyun;An, Zhiguo
摘要大城市的城区和郊区由于环境噪声的影响，给地球物理勘探带来了很大的挑战。这对于可控源音频大地电磁法（CSAMT）尤其如此，因为该方法的频率范围与许多民用和工业噪声的频率范围重叠。在不同类型的噪声源中，最引人注目的也许是50 Hz电网。我们成功地应用CSAMT方法在北京郊区的地下水勘探，环境噪声水平约为正常情况下会遇到的三倍。为确保该方法的高质量使用，采取了若干步骤，包括仔细的勘测设计、适当的频率范围选择、较大的发射器偶极子长度和发射器-接收器间距。下一步是通过低通滤波和地形校正去除静电效应，以去除电场测量中的任何非水平分量。最后，采用一维反演方法对该地区的地震资料进行了反演。
ABSTRACTUrban and suburban areas of large cities impose great challenges to geophysical surveys because of high-level ambient noise. This is particularly true for controlled source audio-frequency magnetotellurics (CSAMT) because the frequency range of the method overlaps those of many civil and industrial noises. Among the different types of noise sources, perhaps the most noticeable one is the 50-Hz power grid. We have successfully applied the CSAMT method for groundwater exploration in a suburban Beijing area where the ambient noise level is about three times as high as would normally be encountered. Several steps were taken in assuring quality use of the method, including careful survey design, adequate frequency range selection, and large transmitter dipole length and transmitter-receiver spacing. The next step was static effect removal through low-pass filtering and topography correction to remove any nonhorizontal component in the electric field measurement. Finally, a 1D inversion method was appli...