Impact of Asphalt and Concrete Pavements on Urban Heat Island and Microclimate Incidents: A Review

Abstract

Urban heat island (UHI) is a real phenomenon and impacts negatively on urban microclimate. Findings from well documented literature reported that dark and impervious pavements surfaces are the key contributing elements to the UHI. The UHI is an incident in which surface and air temperatures increase due to retention and emittance of heat energy from pavements and other manmade hard surfaces. It is a phenomenon whereby ambient temperatures are substantially higher in cities than in rural and suburban areas due to the absorption and accumulation of heat in pavements and other physical interactions. This paper presents a thorough literature review of existing literature on the impact of conventional asphalt and concrete pavements on UHI and microclimate incidents. The work focuses on the impact of these pavements with respect to their contributions to UHI, effect of UHI on urban microclimate, UHI mitigation measures and their associated impact. Primarily, the paper discusses and summarizes the key findings on the UHI phenomenon and its consequences with respect to its harmful effect on the urban wellbeing, particularly on human thermal comfort. Several UHI mitigation measures have been proposed in the existing literature. Specific emphasis is accorded to reflective, permeable and water retentive pavements. However, using a combination of different techniques is deemed as the most effective strategy for reducing the impact of the UHI. This work suggests for further works on UHI mitigation measures for varying seasons and localities around the world to establish the best possible solution.