Cool Pavement Strategies for Urban Heat Island Mitigation in Suburban Phoenix, Arizona

Sustainability

Jeffery Roesler¹  Sushobhan Sen¹  Ariane Middel²  Benjamin Ruddell³ 

[1] Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Ave., Urbana, IL 61801-2352, USA;School of Arts, Media and Engineering, Herberger Institute for Design and the Arts, Arizona State University, P.O. Box 875802, Tempe, AZ 85287-5802, USA;School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Building 90, 1295 S. Knoles Dr., Flagstaff, AZ 86011, USA;

关键词: urban heat islands;    cool pavements;    computational fluid dynamics;    urban microclimate;    22 land cover;   

DOI  :  10.3390/su11164452

来源: DOAJ

【 摘 要 】

Urban areas are characterized by a large proportion of artificial surfaces, such as concrete and asphalt, which absorb and store more heat than natural vegetation, leading to the Urban Heat Island (UHI) effect. Cool pavements, walls, and roofs have been suggested as a solution to mitigate UHI, but their effectiveness depends on local land-use patterns and surrounding urban forms. Meteorological data was collected using a mobile platform in the Power Ranch community of Gilbert, Arizona in the Phoenix Metropolitan Area, a region that experiences harsh summer temperatures. The warmest hour recorded during data collection was 13 August 2015 at 5:00 p.m., with a far-field air temperature of about 42 ${}^{\circ }$ C and a low wind speed of 0.45 m/s from East-Southeast (ESE). An uncoupled pavement-urban canyon Computational Fluid Dynamics (CFD) model was developed and validated to study the microclimate of the area. Five scenarios were studied to investigate the effects of different pavements on UHI, replacing all pavements with surfaces of progressively higher albedo: New asphalt concrete, typical concrete, reflective concrete, making only roofs and walls reflective, and finally replacing all artificial surfaces with a reflective coating. While new asphalt surfaces increased the surrounding 2 m air temperatures by up to 0.5 ${}^{\circ }$ C, replacing aged asphalt with typical concrete with higher albedo did not significantly decrease it. Reflective concrete pavements decreased air temperature by 0.2−0.4 ${}^{\circ }$ C and reflective roofs and walls by 0.4−0.7 ${}^{\circ }$ C, while replacing all roofs, walls, and pavements with a reflective coating led to a more significant decrease, of up to 0.8−1.0 ${}^{\circ }$ C. Residences downstream of major collector roads experienced a decreased air temperature at the higher end of these ranges. However, large areas of natural surfaces for this community had a significant effect on downstream air temperatures, which limits the UHI mitigation potential of these strategies.

【 授权许可】

Unknown