Estimation of the soil thermal conductivity and heat flux in near surface layer from soil emperature

Six methods of calculating the soil thermal conductivity and the soil heat flux in the soil near surface layer are studied with observation of soil temperature. The amplitude, phase, arctangent, and logarithm require only a few measurements of temperature and their calculations are simple. However, the results are erratic. Numerical and harmonic methods, which use much more temperature measurements, generally provide more reliable results. The estimation of soil heat flux, based on the calculated thermal conductivity, is consistent well with values of heat flux determined with the temperature integral method.