Knowledge mapping of cool pavement technologies for urban heat island Mitigation: A Systematic bibliometric analysis

In the last few decades, researchers have sought ways to counterbalance the effect of the urban heat island (UHI) phenomenon of increased urban temperatures resulting from human activities and the surrounding structures. A significant portion of any urban area is made up of paved surfaces, which greatly contributes to the UHI effect. The concept of utilising cool pavement technologies (where `pavement' refers to all paved surfaces) has gained popularity lately. These technologies tend to involve releasing less sensible heat and lowering pavement surface temperatures, which may result in substantial changes to the heating in areas with high urban temperatures. However, no quantitative study of the pertinent numerical features of the research and the development of cool pavement technology research has been published. This paper presents a science mapping and bibliometric analysis of cool pavement technology research represented by 342 selected publications in the Scopus database, a widely recognised scientific database. This analysis revealed that the production of documents related to cool pavements has increased exponentially since 1993, reaching a peak of 44 articles in 2022. China had the most publications, followed by the USA. An analysis of topical trends showed that most research on cool pavement technology has focused on increasing the solar reflectance of the pavement surface-the subject of 159 of the total of 342 documents. Surprisingly, the total number of studies on evaporative pavements was only about one-third of the number (53) conducted on reflective pavements. In addition to research on reflective and evaporative pavements, significant efforts have been undertaken in the past few years to identify techniques to help lower paved surface temperatures to mitigate the UHI effect. This indicates that this research area is still evolving and far from fully mature.