Parameterization and mathematical modeling of the dependence of soil thermal diffusivity on the water content

Functional dependences of the thermal diffusivity of soil horizons on their water contents obtained via parameterization of experimental curves are used for the mathematical modeling of the soil temperature regime. If there are no experimental data on thermal diffusivity, parameters of the functional dependence may be calculated from data on the major soil properties. A lognormal function describes experimental dependences of the thermal diffusivity of soil horizons on their water content more accurately than power and polynomial functions. Regression equations making it possible to calculate the thermal diffusivity of gray forest soils on the basis of data on their bulk density, water content, organic matter content, and particle-size distribution are suggested.