Integrating four radiant heat load mitigation strategies is an efficient intervention to improve human health in urban environments

• Published in: The Science of the total environment Vol. 698; p. 134259
• Main Authors: Park, Chae Yeon, Yoon, Eun Joo, Lee, Dong Kun, Thorne, James H.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2020
• Subjects: Cities; Environmental Exposure - statistics & numerical data; Green infrastructure; Heat mitigation; Heat mortality; Hot Temperature; Humans; Mean radiant temperature; NSGA II; Optimization; Pedestrians; Poaceae; Temperature; Trees; Cities; Heat mitigation; Mean radiant temperature; Green infrastructure; Optimization; Heat mortality; NSGA II
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.134259

Increasing heat in urban areas raises heat-related health risks. Green infrastructure and managing surface albedo can reduce the radiation exposure of pedestrians. However, selecting options among various radiant fluxes mitigation strategies is challenging, particularly due to potential interactions among options such as planting vegetation or changing surface albedos. We used a multi-strategies model for determining optimal design combinations for reducing mean radiant temperature (MRT) in urban environments across a range of costs and benefits. The solutions are developed by a non-dominated sorting genetic algorithm II (NSGA II) with a MRT simulator. We selected four MRT reduction strategies: tree planting, grass planting, albedo reduction of building walls, and albedo reduction of sidewalks. Model test results for a simulated street canyon show a wide range of optimal alternative plans considering the combination effects of the four strategies. While previous studies have focused on single options to reduce heat load, we found benefits were higher by using a combination of these strategies, which can provide synergistic benefits. These results provide useful information for decision makers confronting real world problems such as heat related mortality. Thermal-friendly design methods and green infrastructure will help the urban environment become sustainable and improve human health and well-being. [Display omitted] •Solutions to reduce MRT can be informed by using meta-heuristics.•We evaluated multiple combinations of four options to reduce MRT.•Synergistic combination effects occur when applying strategies together.•The model identifies optimal options that maximize MRT reduction and minimize costs.•These optimal solutions can inform cost-effective planning to reduce mortality.