Mineral Soil Texture–Land Cover Dependency on Microwave Dielectric Models in an Arid Environment

In this study, we measured and characterized the relative dielectric constant of mineral soils over the 0.3–3.0 frequency range, and compared our measurements with values of three dielectric constant simulation models (the Wang, Dobson, and Mironov models). The interrelationship between land cover and soil texture with respect to the dielectric constant was also investigated. Topsoil samples (0–10 cm) were collected from homogenous areas based on a land unit map of the study site, located in the Gamsar Plain in northern Iran. The field soil samples were then analyzed in the laboratory using a dielectric probe toolkit to measure the soil dielectric constant. In addition, we analyzed the behaviors of the dielectric constant of the soil samples under a variety of moisture content and soil fraction conditions (after oven-drying the field samples), with the goal of better understanding how these factors affect microwave remote sensing backscattering characteristics. Our laboratory dielectric constant measurements of the real part (ε′) of the frequency dependence between the factors showed the best agreement with the results obtained by the Mironov, Dobson, and Wang models, respectively, but our laboratory measurements of the imaginary part (ε″) did not respond well and showed a higher value in low frequency because of salinity impacts. All data were analyzed by integrating them with other geophysical data in GIS, such as land cover and soil textures. The result of the dielectric constant properties analysis showed that land cover influences the moisture condition, even within the same soil texture type.