Spatial variation in temperature of urban space and urban heat island differentials in Warri metropolis, Nigeria

Abstract

Urban Heat Island (UHI) has become one of the greatest problems associated with urban growth and industrialization. This is because of the elevated temperature associated with it. This paper examined spatial variation in temperature of urban space and magnitude of Urban Heat Island in Warri Metropolis, Nigeria. The study proceeded by stratifying the study area into four (Jakpa, Giwa-Amu, Airport Road and Okumagba Layout) and selected a peri-urban conurbation (Oha) as a control. Quasi-experimental (ex-post-facto) research design was adopted for the study. Secondary data of minimum and maximum temperature for a period of 30 (1992-2021) years was used. The study found that mean annual maximum temperature for Warri was 31 ºC compared to that of Oha (27.3 ºC). Minimum temperature for Warri was 23.2 ºC while Oha was 21 ºC. Generally, the mean temperatures for the Warri locations were higher than that of Oha. The UHI values, for Jakpa and Airport road were similar with UHI values of 1ºC respectively. Giwa Amu recorded 1.1 ºC, while Okumagba recorded UHI value of 1.2 ºC. The ANOVA model comparing the temperature values for the study area was significant at P<0.05 (F-62.7; sig-.000). Implying that there is a significant spatial variation in temperature of Warri; and Oha was significantly cooler with a temperature of 27.1 ºC. The paired sample t test comparing mean temperature in Warri and Oha was significant at p<0.05 (t-22.9; sig-.000). This implied that there is a significant difference between mean temperature in Warri and that of Oha. Therefore, tree planting, urban planning was among the recommendations advanced in the study.