Abstract
With rapid urbanization, population growth and anthropogenic activities, an increasing number of major cities across the globe are facing severe urban heat islands (UHI). UHI can cause complex impacts on the urban environment and human health, and it may bring more severe effects under heatwave (HW) conditions. In this paper, a holistic review is conducted to articulate the findings of the synergies between UHI and HW and corresponding mitigation measures proposed by the research community. It is worth pointing out that most studies show that urban areas are more vulnerable than rural areas during HWs, but the opposite is also observed in some studies. Changes in urban energy budget and major drivers are discussed and compared to explain such discrepancies. Recent studies also indicate that increasing albedo, vegetation fraction and irrigation can lower the urban temperature during HWs. Research gaps in this topic necessitate more studies concerning vulnerable cities in developing countries. Moreover, multidisciplinary studies considering factors such as UHI, HW, human comfort, pollution dispersion and the efficacy of mitigation measures should be conducted to provide more accurate and explicit guidance to urban planners and policymakers.
Highlights
Lan DingDue to increasing populations, cities all over the world have been developing both horizontally and vertically to accommodate their increasing needs [1]
Cities all over the world have been developing both horizontally and vertically to accommodate their increasing needs [1]. Such urbanization has contributed to urban climate change due to the replacement of natural elements with artificial heat-absorbing features that have a relatively low albedo, high solar absorption and high heat capacity [1,2,3,4,5,6,7]
Cities often present a higher ambient temperature than their surrounding suburban and rural areas, especially at night, and this phenomenon is widely known as urban heat island (UHI) [4,13,14]
Summary
Cities all over the world have been developing both horizontally and vertically to accommodate their increasing needs [1] Such urbanization has contributed to urban climate change due to the replacement of natural elements (e.g., water, vegetation) with artificial heat-absorbing features (e.g., concrete, asphalt) that have a relatively low albedo, high solar absorption and high heat capacity [1,2,3,4,5,6,7]. Cities often present a higher ambient temperature than their surrounding suburban and rural areas, especially at night, and this phenomenon is widely known as urban heat island (UHI) [4,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
