Study on soil dielectric constant models: A review

Abstract

【Objective】 Soil dielectric constant measures the ability of a soil to transmit electric fields. It is the ratio of the capacitance of a soil sample to the capacitance of air-filled space of the same volume. In this paper, we systematically analyze the factors that influence the dielectric constant, offering an updated perspective on soil dielectric constant modeling. 【Method】 This study systematically identifies the primary factors influencing soil dielectric constant based on soil dielectric theory. Additionally, it categorizes and summarizes existing soil dielectric constant models, facilitating a comparative analysis of their strengths, weaknesses, applications, and future development. 【Result】 The primary influencing factors governing the dielectric constant varied with soil types, with notable dependence on testing frequency. However, the dielectric constant remains a valuable indicator of soil water content. The soil dielectric constant models were broadly categorized into four types: theoretical, semi-empirical, empirical, and boundary models. 【Conclusion】 Presently, there is a dearth of research focusing on the dielectric properties and model development specific to regional soils. Enhancing model accuracy necessitates incorporating the influence of soil-phase composition, mineral composition, and microstructure on the dielectric constant. This refinement will broaden the application studies for assessing and analyzing soil physical and chemical properties based on dielectric constant testing.

Keywords

• soil
• water content
• electromagnetic wave
• dielectric constant
• model