Potential Influence of Urban Sprawl and Changing Land Surface Temperature on Outdoor Thermal Comfort in Lagos State, Nigeria

Jerry N Obiefuna,Lawrence C Isiofia,Chukwuma J Okolie,Peter C Nwilo,Olagoke E Daramola

doi:10.2478/quageo-2021-0001

Jerry N Obiefuna, Lawrence C Isiofia + Show 3 more

Open Access

https://doi.org/10.2478/quageo-2021-0001

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Abstract

Abstract The continuous monitoring of the relationship between land surface temperature (LST) and land cover change is imperative for an inquiry into the potential impact of LST on human well-being, including urban outdoor thermal comfort in Lagos State, Nigeria. Using Landsat imagery, this study assessed land cover and LST changes from 1984 to 2019. Land cover was extracted, LST was determined from Landsat imageries and the land cover changes were linked to LST using the contribution index (CI). Afterwards, the universal thermal climate index (UTCI) was calculated to determine the heat stress levels. Findings confirm the presence of urban sprawl and new growth areas in previously rural Local Government Areas (LGAs) eastward, northward and westward of Lagos metropolis and in regions which lie on the fringe of the state's border with Ogun State. Also, a very strong link between high LST intensities and increasing concentration of urban areas in rapidly growing LGAs has been observed. This link further confirms the increased warming of the state, with an increase in mean LST of 2.16°C during 1984–2019. The UTCI which was used to gauge the influence of LST on outdoor thermal comfort ranged from moderate to strong heat stress levels. This study helps to strengthen the case for definite policies and actions which should be aimed at achieving moderate urban development through increased urban tree canopy/green infrastructure provision and carbon sequestration activities in urban design/landscape design, in Lagos State.

Highlights

Urbanisation, which is the gradual shift in the residence of human populations from rural to urban areas (UN 2018), is one of the most obtrusive human actions, and gives rise to irreversible effects on the earth’s surface and biosphere
While the study established the fact of rapid and continuing urban expansion into hitherto rural areas along with continuing warming of the state, it indicated a strong link between high land surface temperature (LST) intensities and rapid urban growth in some Local Government Areas (LGAs)
The universal thermal climate index (UTCI) heat stress index derived for the state with LST results points to a potential influence of LST and urban heat island (UHI) on the outdoor thermal comfort in the state

Summary

Introduction

Urbanisation, which is the gradual shift in the residence of human populations from rural to urban areas (UN 2018), is one of the most obtrusive human actions, and gives rise to irreversible effects on the earth’s surface and biosphere. These shifts in land use and territorial occupation of urban areas, as observed in Gómez et al (2020), are topical issues at global, regional and national levels owing to their impacts on ecological and environmental systems, among others. This growth will lead to urban expansion, an increase in demand for housing and urban infrastructure and increased pressure on environmental resources for human sustenance

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