Measuring the impacts of a real-world neighborhood-scale cool pavement deployment on albedo and temperatures in Los Angeles
Measuring the impacts of a real-world neighborhood-scale cool pavement deployment on albedo and temperatures in Los Angeles
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DOI：
10.1088/1748-9326/ac58a8
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发表时间：
2022-04-01
影响因子：
6.7
通讯作者：
Ban-Weiss, George
中科院分区：
文献类型：
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作者：
Ko, Joseph;Schlaerth, Hannah;Ban-Weiss, George
气候变化预计将加剧全球城市的城市热岛效应，增加与热有关的发病率和死亡率的风险。太阳能反射“冷路面”是几种缓解策略之一，可以抵消的负面影响的城市热岛效应。路面反射率的增加会导致热量吸收减少，从而导致表面温度（T（表面））降低。如果在足够大的空间尺度上铺设凉爽的路面，也可以降低近地表空气温度（T（空气）），尽管这从未得到现场测量的证实。这项实地研究是第一次进行控制测量的影响，邻里规模的凉爽路面安装。我们测量了凉爽路面对温度、表面温度和空气温度的影响。此外，在安装后监测路面的老化情况，以评估其随时间的退化情况。现场（约0.64 km（2））位于加州的科布伦茨;约洛杉矶市中心以东30 km。我们发现，0.18（从0.08到0.26）的平均路面反射率增加对应于最大邻域平均T（表面）和T（空气）分别降低5摄氏度和0.2摄氏度。下午观察到最大T（表面）降低，而上午观察到最小降低0.9摄氏度。在当地标准时间（LST）12：00和从20：00 LST到22：59 LST检测到T（空气）减少，表明凉爽的路面在白天和晚上都会降低T（空气）。30%的平均温度降低对应于T（表面）冷却效率降低1摄氏度。虽然我们在这里介绍了第一次测量的T（空气）减少由于凉爽的路面，我们强调，T（空气）减少和反射短波辐射增加之间的权衡仍然不清楚，需要进一步调查，以全面评估凉爽的路面的功效，特别是关于行人的热舒适性。
Climate change is expected to exacerbate the urban heat island (UHI) effect in cities worldwide, increasing the risk of heat-related morbidity and mortality. Solar reflective 'cool pavement' is one of several mitigation strategies that may counteract the negative effects of the UHI effect. An increase in pavement albedo results in less heat absorption, which results in reduced surface temperatures (T (surface)). Near surface air temperatures (T (air)) could also be reduced if cool pavements are deployed at sufficiently large spatial scales, though this has never been confirmed by field measurements. This field study is the first to conduct controlled measurements of the impacts of neighborhood-scale cool pavement installations. We measured the impacts of cool pavement on albedo, T (surface), and T (air). In addition, pavement albedo was monitored after installation to assess its degradation over time. The field site (similar to 0.64 km(2)) was located in Covina, California; similar to 30 km east of Downtown Los Angeles. We found that an average pavement albedo increase of 0.18 (from 0.08 to 0.26) corresponded to maximum neighborhood averaged T (surface) and T (air) reductions of 5 degrees C and 0.2 degrees C, respectively. Maximum T (surface) reductions were observed in the afternoon, while minimum reductions of 0.9 degrees C were observed in the morning. T (air) reductions were detected at 12:00 local standard time (LST), and from 20:00 LST to 22:59 LST, suggesting that cool pavement decreases T (air) during the daytime as well as in the evening. An average albedo reduction of 30% corresponded to a similar to 1 degrees C reduction in the T (surface) cooling efficacy. Although we present here the first measured T (air) reductions due to cool pavement, we emphasize that the tradeoffs between T (air) reductions and reflected shortwave radiation increases are still unclear and warrant further investigation in order to holistically assess the efficacy of cool pavements, especially with regards to pedestrian thermal comfort.