Soil Dielectric Model Accounting for Contribution of Bound Water Spectra through Clay Content

In this paper, there was studied correlation of dielectric predictions for moist soils with the measured values, regarding the well known and prevalent in common usage semiempirical mixing dielectric model (SMDM) proposed by M. C. Dobson et al., on the one hand, and the generalized refractive mixing dielectric model (GRMDM) proposed by V. L. Mironov et al., on the other hand. The analysis is based on the measured dielectric data borrowed from the Technical Report EL-95-34, by J. O. Curtis et al., in which the assemblage of soils measured included all of grain-size distributions that are observed in nature, with measurements being performed over the frequency range from 45MHz to 26.5GHz at the moistures spanning from the nearly dry samples to the ones saturated close to total moisture capacity. The GRMDM was found to provide for much more accurate dielectric predictions. To make the GRMDM as convenient for the users, as the semiempirical model is, which uses only clay and sand contents as the only input parameters, the spectroscopic parameters of the GRMDM were linked to the clay content. As a result, a new type of mineralogy based soil dielectric model (MBSDM) was developed to provide for much better accuracy of dielectric predictions over a broader variety of soil types, as compared to those of the SMDM.