Physics
Permanent URI for this communityhttps://repository.ui.edu.ng/handle/123456789/358
Browse
2 results
Search Results
Item Assessment of Soil Thermal Properties in a Tropical Environment: Ile Ife and Ibadan(Journal of Faculty of Science, University of Ibadan, Ibadan, Nigeria., 2011) Otunla T.A.; Oladiran E.O.Soil thermal properties are crucial parameters that affect soil heat flux. Time series of soil temperature, soil moisture content, and rainfall and soil heat flux were measured at two tropical locations in West Africa during the transition from dry to wet season, and at the peak of rainy season in July. The data were analyzed to estimate soil thermal diffusivity, thermal inertia and volumetric heat capacity. The thermal properties were clearly related to soil moisture (and thus rainfall) throughout the measurement period. The modeled soil heat flux using the soil thermal properties compared favorably with the measured soil heat flux.Item "Evaluation of soil thermal diffusivity algorithms at two equatorial sites in West Africa"(2021) Otunla, T.A.; Oladiran, E. O.This study presents comparisons between six algorithms used in the calculation of apparent thermal diffusivity (Kh ) of the topsoil during measurement campaigns conducted at two equatorial sites. It further investigates the effects of transient and seasonal variations in soil moisture content (i) on the estimation of Kh. The data used comprise soil temperatures (T) measured at depths of 0.05 m and 0.10 m, and i within the period of transition from the dry season to the wet season at Ile Ife (7.55° N, 4.55° E), and for the peak of the wet season at Ibadan (7.44° N, 3.90° E). The thermal diffusivity, Kh, was calculated from six algorithms, of: harmonic, arctangent, logarithmic, amplitude, phase, and conduction-convection. The reliability of these algorithms was tested using their values to model T at a depth of 0.10 m, where direct measurements were available. The algorithms were further evaluated with statistical indices, including the empirical probability distribution function of the differences between the measured and modeled temperatures (DT). The maximum absolute values of DT for the six algorithms investigated were: 0.5°C, 0.5°C, 0.5°C, 1°C, 1°C and 1°C, respectively. Kh showed an increasing trend as i increased from the dry season to the peak of the wet season, with R2 = 0.70 for the harmonic algorithm. The accuracy of all of the algorithms in modeling T reduced with transient variations of i. The harmonic, arctangent and logarithmic algorithms were the most appropriate for calculating Kh for the region of study. The empirical relation between i and Kh and the values of Kh obtained in this study can be used to improve the accuracy of meteorological and hydrological models.