A comparative study of computing methods of soil thermal diffusivity, temperature and heat flux
The measurements from "The Oasis System Energy and Water Cycle Field Experiment" were taken over a farmland underlying surface in the Jinta Oasis of Gansu Province during a period from 11 to 15 June, 2005. Based on the analyses of the characteristics of soil temperature, soil moisture and soil heat flux, the thermal diffusivity of 5~20 cm soil layer is calculated by using four methods (Amplitude method, Phase method, Harmonic method, and Conduction-convection method). Taking the 5 cm soil temperature as the upper boundary, the soil temperature of the depth 10 cm and 20 cm and the heat flux of the depth 10 cm are modeled by the four methods. The results showed that the soil temperature modeled by Harmonic method is the most accurate, the standard errors of the two depth modeled values against the observation are 0.21 'C and 0. 18 'C. The Conduction-convection method provided better temperature modeled results than Amplitude method and Phase method, but the results would have errors when the method is used to simulate the temperature of shallow soil whose moisture has a significantdiurnal variation. The soil heat flux modeled by Harmonic method is better than any other method mentioned above, the correlation coefficient between the modeled value and the observation is 0. 868.
NETL
NSTL
万方数据
维普
