Urban heat islands: a review of contributing factors, effects and data

Abstract Urban Heat Island (UHI) is one of the most serious difficulties that humans have faced in the twenty-first century resulted due to urbanization and industrialization. The main causes of UHI are the vast amounts of heat produced by urban structures, which solar energy should be used and re-radiated as well as anthropogenic heat sources. The two heat sources cause an urban area’s temperature to rise in comparison to its surrounding areas, which refers to a phenomenon of the urban heat islands. Large cities and diverse economic activities face even more serious difficulties. This paper defined the concept and types of UHIs. This paper explained a comprehensive review of the phenomenon of UHI from its first appearance with regard to causing factors, its influences on people’s lives and the urban environments, and widely used data for measuring and evaluating the intensity of UHIs. The finding of most studies mentioned that UHI values are different from city to city based on land-use changes. It is revealed that an increasing trend occurred mainly because expand in built-up areas and a reduction in green cover. Also, a number of studies showed that the UHI intensity was low during summer afternoons and high during winter nights in many places around the world.