Urban street canyons and heat islands: A systematic review on morphological solutions

The lack of preventive measures to curb the expansion of urban heat islands and the associated global challenges, particularly climate change, necessitates serious follow-up and the development of solutions, along with the implementation of strict regulations at urban, national, and international levels. The uncontrolled growth of urban street canyons, coupled with insufficient attention to their morphological characteristics, exacerbates heat islands by altering the microclimatic conditions of cities. This phenomenon traps heat and pollution within the urban fabric, amplifying risks on a large scale. This review, focusing on the importance of optimizing urban street canyon conditions and microclimates, suggests that achieving optimal configurations for urban blocks can help regulate thermal comfort for citizens while also providing economically viable land-use ratios in dense urban areas. These findings can guide architects and urban planners in addressing climatic challenges and improving urban living conditions. However, previous research has identified several shortcomings that hinder the achievement of optimal and efficient urban structures. To better pave the way forward, this article reviews the existing literature, highlights these obstacles, and offers recommendations for future studies to propose more effective solutions.