Digging up the Past: Re-Visiting the Potential Role Green Roofs can Play in Mitigating the Urban Heat Island (UHI) Effect: A Case Study of the Central Business District (CBD), Durban, South Africa

Abstract

Across the world, cities and densely populated areas are striving to both uplift the quality of the environment as well as enhance their sustainability. Part of this endeavour entails the promotion of urban greening. In Durban, on the east coast of South Africa, rooftop greening practices are gaining some traction with a view to achieving the sustainable development of a greener environment for the city and surrounding areas, although on a smaller scale than many other cities. There has been little empirical research done on green roofs within a local context, especially concerning green roofs as green infrastructure in urban planning tools for creating sustainable resilient city spaces by helping them mitigate against climate change. The quantitative analysis of this research measured temperatures and the urban heat island effect (UHI) of green roofs, as well as control sites over a seven-year period. The total average temperature differences over a seven-year period during the summer months (January/February) witnessed one green roof measuring 9.2 degrees Celsius lower than the control roof. The rationale for this research was to offer support for the benefits of green roofs in mitigating against an increase in inner-city heat islands in the case of Durban’s Central Business District (CBD).