Survey of a heavy metal polluted field site based on spectrum-induced polarization
The experimental site is located in a village in Zhenjiang city, Jiangsu Province, with an altitude of approximately 30 m. The survey area is relatively flat and belongs to a low mountainous and hilly area with a more complex topography, with mountains to the south. The northeast side is close to the Jiajiang River, a tributary of the Yangtze River, which is located at midlatitude in the northern subtropics and has an oceanic climate. There are a number of high-voltage towers with more serious electromagnetic coupling interference at the experimental site. Part of the contaminated soil is strongly acidic, causing a greater impact on the lives of nearby residents. The highest chromium metal content is identified through physical analysis in most areas, which is a typical heavy metal contaminated site.
Steps to reproduce
Field spectrum excitation detection using gradient devices. Receiving electrodes M0 ~ M8 use a low-frequency electric field sensor group that constitutes 8-channel sampling. The spacing is 1 m at a fixed position, and the distance of the transmitting electrode AB is 5 m, moving 1 m toward the center each time. For each measurement, we emit 27 pseudorandom sequences with a base frequency of 0.015625 Hz, in which the sampling rate is 25 kSPS and the transmitter emission voltage is 300 V. The noise of the obtained original target signal is first reduced using the suggested method during data processing, and then the Cole-Cole model inversion is used to produce the final figure.