Abstract

Application of a set of electrical methods used in geophysics—direct current resistance and induced polarization—for the purposes of mapping soil heterogeneity is considered. In the field, we measured the parameters of specific electrical resistance (SER) and induced polarization (IP) of shungite soils of the Zaonezhskii Peninsula (Republic of Karelia) using the A–M–N–B electrode installation with spacings of 15 cm. To ensure the interpretation adequacy, the relative soil water content and the soil texture were determined. Using the map of resistivity values, spatial variations in the soil water content and, partially, in the soil texture were estimated. The map of IP values was used to find out spatial variations in the composition of soils, including, in particular, the content of shungite. The analysis of the correlative dependence of the electrophysical parameters on the soil water content showed that the Spearman coefficient r_s is –0.426 for SER and 0.076 for IP, which confirms the hypothesis about different levels of influence of the water content on these parameters. In the course of studying the influence of the frequency of the generated electric signal, an increase in the IP intensity was found in the frequency range of 0.01–0.1 Hz for the soils with elevated carbon content. The analysis of soil samples demonstrated that the IP anomalies within the studied area may be related to variations both in the soil texture and in the shungite material content. Hence, the electrophysical indicators determined under natural conditions can be applied to characterize the spatial variations in soil water content, soil texture, and some structural properties of the soils.

中文翻译：

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地电方法在土壤异质性制图中的应用

摘要

为了绘制土壤异质性，考虑了地球物理中使用的一组电气方法的应用（直流电阻和感应极化）。在野外，我们使用间隔为15 cm的A–M–N–B电极装置，测量了Zaonezhskii半岛（卡累利阿共和国）的褐铁质土壤的比电阻（SER）和感应极化（IP）的参数。为了确保解释的适当性，确定了相对土壤含水量和土壤质地。使用电阻率值图，可以估算土壤含水量以及部分土壤质地的空间变化。IP值图用于找出土壤成分的空间变化，特别是包括菱铁矿的含量。SER的r _s为–0.426，IP的r _s为0.076，这证实了水含量对这些参数的影响程度不同的假设。在研究产生的电信号的频率的影响的过程中，对于碳含量较高的土壤，IP强度在0.01-0.1 Hz的频率范围内有所增加。对土壤样品的分析表明，研究区域内的IP异常可能与土壤质地和菱铁矿材料含量的变化有关。因此，在自然条件下确定的电物理指标可用于表征土壤含水量，土壤质地和土壤某些结构特性的空间变化。