Urban heat dynamics in Local Climate Zones (LCZs): A systematic review

Urban Heat Islands (UHIs) present significant challenges for urban areas worldwide, impacting public health and the overall livability of cities. This systematic literature review explores UHI effects across different Local Climate Zones (LCZs) and suggests mitigation strategies. Key contributors to UHI effects within various LCZs include inefficient building layouts, high building densities, and insufficient vegetation coverage. Conversely, potential mitigation measures like increasing surface albedo and enhancing green spaces offer promising ways to alleviate UHI effects and improve thermal comfort. The study identifies the hottest and coolest LCZs at both Surface Urban Heat Island (SUHI) and Canopy Urban Heat Island (CUHI) levels, uncovering disparities depending on measurement heights. It identifies LCZ 2 as the hottest in both SUHI and CUHI categories, while highlighting LCZ 9, with its sparse development, as the coolest built-up area in both cases. Results confirm that compact designs provide shading effects during daytime assessments but trap heat at night, leading to elevated temperatures - exemplified by LCZ 1 being among the coolest during daylight but emerging as one of the hottest compact forms at night. Additionally, results reveal that low-rise areas in LCZ 10 and 8 are most problematic due to substantial heat accumulation attributed to limited vegetation cover and extensive concrete usage. Most publications discussed three important mitigation strategies: increasing green space and plants, increasing the previous surface percentage, and using reflective building materials. The findings underscore tailored approaches for addressing urban heat challenges and climate change adaptation based on the specific characteristics of each LCZ.