2021_4_06_field_trial

The experimental data is the field detection data of a heavy metal contaminated site in the field by using the spectrum induced polarization method. (1) The experimental site is located in a village in Zhenjiang City, Jiangsu Province. The survey area is about 30 m above sea level, and the terrain is relatively flat. It belongs to a low mountain and hilly area with complex terrain. It is close to the mountain in the South and the Jiajiang River, a tributary of the Yangtze River, in the northeast. It is located in the north subtropical zone at mid latitude, and belongs to a marine climate. (2) There are many high-pressure towers at the experimental site, which have serious electromagnetic coupling interference. Some areas have heavy metal pollution sources in the deep part as shown in Figure 8, and some polluted soils are strongly acidic, which has a great impact on the lives of nearby residents. Through physical property analysis, it is found that most areas in this area have the highest chromium content, which is a typical heavy metal pollution site. (3) Gradient device is used for on-site spectrum IP detection. The receiving electrode m0~m8 uses low-frequency electric field sensor group to form 8-channel sampling. The position is fixed at a distance of 5m, and the transmitting electrode AB is 30m, moving 5m to the center each time. (4) During each measurement, 27 pseudo-random sequences with a fundamental frequency of 0.015625 Hz are transmitted, the sampling rate is 2 ksps, and the transmitter transmission voltage is 300 v.