Assessment and modelling of soil moisture content in silty loess using electrochemical impedance spectroscopy

IF 5.7 1区农林科学 Q1 GEOSCIENCES, MULTIDISCIPLINARY

Catena Pub Date : 2025-08-29 DOI:10.1016/j.catena.2025.109408

Funan Sun , Bin He , Pengju Han

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引用次数: 0

Abstract

The structure and stability of silty loess are closely linked to variations in the moisture content and temperature. The advantages of alternating current electrochemical perturbations in capturing high-frequency impedance responses provide comprehensive insights for analysing the interplay between temperature and moisture in silty loess. This study investigates the electrochemical characteristics of silty loess under different temperatures and moisture contents using electrochemical impedance spectroscopy (EIS). Experimental and modelling results revealed that the complex impedance curve of frozen silty loess exhibited distinct electrochemical phenomena: the first capacitive arc in the high-frequency domain corresponded to bound water (near-water layer), whereas the second continuous semi-circular capacitive arc represented free water (far-water layer). The electrochemical characteristics of the silty loess were modelled using an (RC) circuit when the moisture content was below the plastic limit. The electrochemical characteristics were characterised by the dual effect of the (RC)(RC) circuit model in series after freezing, which represents the bound and free water applicable to moisture contents above the plastic limit. The evolution patterns of the equivalent circuit models were identified based on the impedance response over a wide frequency range. A mathematical relationship was established between different moisture content components and electrochemical parameters, expressed as ω = a(ln(R))^-^b. These results improve the understanding of the variation mechanisms in soil moisture through EIS and provide valuable references for further research on the soil electrochemical impedance theory.

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基于电化学阻抗谱的粉质黄土土壤含水量评价与建模

粉质黄土的结构和稳定性与含水率和温度的变化密切相关。交流电化学扰动在捕获高频阻抗响应方面的优势为分析粉质黄土中温度和水分的相互作用提供了全面的见解。利用电化学阻抗谱（EIS）研究了不同温度和含水量下粉质黄土的电化学特性。实验和模拟结果表明，冻结粉质黄土的复杂阻抗曲线表现出明显的电化学现象：高频域的第一个电容弧对应于束缚水（近水层），而第二个连续的半圆形电容弧代表自由水（远水层）。采用RC电路模拟了含湿量低于塑性极限时粉质黄土的电化学特性。电化学特性表现为冻结后（RC）（RC）串联电路模型的双重效应，即适用于塑性极限以上水分含量的束缚水和自由水。基于宽频率范围内的阻抗响应，确定了等效电路模型的演化模式。建立了不同含水率组分与电化学参数之间的数学关系，表示为ω = A (ln(R))-b。这些结果提高了我们对土壤水分变化机理的认识，为土壤电化学阻抗理论的进一步研究提供了有价值的参考。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Catena 环境科学-地球科学综合

CiteScore

10.50

自引率

9.70%

发文量

816

审稿时长

54 days

期刊介绍： Catena publishes papers describing original field and laboratory investigations and reviews on geoecology and landscape evolution with emphasis on interdisciplinary aspects of soil science, hydrology and geomorphology. It aims to disseminate new knowledge and foster better understanding of the physical environment, of evolutionary sequences that have resulted in past and current landscapes, and of the natural processes that are likely to determine the fate of our terrestrial environment. Papers within any one of the above topics are welcome provided they are of sufficiently wide interest and relevance.