Estimation of thermal inertia of Abeokuta Ogun State, southwestern Nigeria

Abstract

Thermal inertia (I) is an important parameter in the Earth’s thermal study. There is no doubt that correct and up-to-date knowledge of thermal inertia particularly as it is affected by the land use/cover will provide good and useful information to agriculturists and environmental scientists. In this work, thermal inertia of Abeokuta City of Ogun State, southwestern Nigeria, was determined. Map of the study area was gridded using 2-min resolution which gave 5 × 5 sampling points from where core samples were collected. Bulk density (ρs), thermal conductivity (λs), and heat capacity (Cs) of the samples were determined. The pattern of variation of the city view of I (in the order of ×103 Jm−2 s−1/2 K−1) showed that the main urban built-up part of the study area, Abeokuta South, had the highest Imean, 0.76160 with standard deviation of 0.032547 and standard error of 0.01455541. The trend also varied along each sampling latitudinal line. It ranges between 0.509 and 0.756 on latitude 7° 14′, 0.557 and 0.768 on latitude 7° 12′, 0.642 and 0.782 on latitude 7° 10′, 0.7 and 0.794 on latitude 7° 08′, and between 0.642 and 0.728 on latitude 7° 06′. Hence, we have estimated thermal inertia of Abeokuta using the thermophysical properties of the study area. Thermal inertia tends to gradually decrease with distance from the city center (Abeokuta South). This result is promising in possible future consideration of urban ground heat energy conversion to other forms of energy.