Improving spatial modeling framework to assess the impact of vegetation cover, water content, and surface temperature on urban heat island effects in Johannesburg, South Africa

Abstract The urban heat island has become a major environmental and socioeconomic concern in the City of Johannesburg Metropolitan Municipality (CoJ), South Africa. This research investigates vegetation characteristics in reducing urban heat islands (UHI) in the CoJ using multispectral and thermal r...

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Bibliographic Details
Main Authors: Eskinder Gidey, Paidamwoyo Mhangara
Format: Article
Language:English
Published: Springer 2025-06-01
Series:Discover Environment
Subjects:
Online Access:https://doi.org/10.1007/s44274-025-00264-0
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Summary:Abstract The urban heat island has become a major environmental and socioeconomic concern in the City of Johannesburg Metropolitan Municipality (CoJ), South Africa. This research investigates vegetation characteristics in reducing urban heat islands (UHI) in the CoJ using multispectral and thermal remote sensing data from 1993 to 2023. The primary indices processed—including the Modified Soil Adjusted Vegetation Index (MSAVI2), Normalized Difference Moisture Index (NDMI), and Urban Heat Island (UHI)—were all analyzed using ArcGIS Pro v3.1.4183 geospatial software. A regression model determined the type and degree of relationship among the indices. Results showed that vegetation cover and water content status were below average, with MSAVI2 = 0.18 and NDMI = – 0.15. The surface temperature was found to be 17.08 °C. A significant, positive statistical relationship (R2 = 0.36; p < 0.01; n = 1,048,575) existed between MSAVI2 and NDMI, indicating that MSAVI2 tends to increase in proportion to an increase in NDMI. A weakly negative statistical relationship existed between MSAVI2 and UHI (R2 = 0.08; p < 0.01; n = 1,048,575), showing that UHI tends to decrease as MSAVI2 increases. Furthermore, a strongly negative, statistically significant relationship existed between NDMI and UHI (R2 = 0.54; p < 0.01; n = 1,048,575), demonstrating that UHI decreases when NDMI rises. Creating environmentally and economically sustainable parks and green urban spaces can help mitigate the effects of urban heat islands.
ISSN:2731-9431