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The Subsurface Urban Heat Island Intensity in Enugu Urban, Nigeria

Urbanisation over the past hundred years has caused environmental and thermal influences underground; yet little knowledge exists about subsurface warming in Enugu, despite previous studies confirming the presence of urban heat island in the area. This study analysed the subsurface urban heat island intensity in Enugu urban, using secondary urban subsoil temperature data set that was sourced from the Nigerian Meteorological Agency over 21 years (2000-2020). With an application known as grid, the rural subsoil temperature data set was gotten by downscaling that of the urban which is 40 km away. The statistical technique employed was Welch’s t-test. The study showed that the annual mean urban subsoil temperatures were generally warmer than that of the rural subsoil temperatures, with a mean difference or subsurface urban heat island intensity of 0.4°C. From the study, it was clear that the urban heat island effect occurred in the subsurface in Enugu, as it does above the ground. This study, to define urban and rural better, suggests that the use of the Local Climate Zone classification scheme should be considered in further research. A joint investigation of the three urban heat island categories in Enugu should also receive top priority in subsequent studies.

Enugu, Subsurface, Urban Heat Island Intensity, Urbanisation, Welch’s T-test

Francis Chibuike Nwalozie, Ifeanyi Christian Enete. (2023). The Subsurface Urban Heat Island Intensity in Enugu Urban, Nigeria. International Journal of Environmental Protection and Policy, 11(4), 57-62.

Copyright © 2023 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License ( which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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