University of California-Riverside, Center for Conservation Biology, 900 University Ave., Riverside, CA 92521, United States; University of California-Riverside, Department of Botany and Plant Sciences, 900 University Ave., Riverside, CA 92521, United States.
University of California-Riverside, Department of Botany and Plant Sciences, 900 University Ave., Riverside, CA 92521, United States.
Sci Total Environ. 2016 Apr 1;548-549:60-71. doi: 10.1016/j.scitotenv.2016.01.049. Epub 2016 Jan 19.
Urbanization has increased heat in the urban environment, with many consequences for human health and well-being. Managing climate change in part through increasing vegetation is desired by many cities to mitigate current and future heat related issues. However, little information is available on what influences the current effectiveness and availability of vegetation for local cooling. In this study, we identified the variation in the interacting relationships among vegetation (normalized difference vegetation index), socioeconomic status (neighborhood income), elevation and land surface temperature (LST) to identify how vegetation based surface cooling services change throughout the pronounced coastal to desert climate gradient of the Los Angeles, CA metropolitan region, a megacity of >18 million residents. A key challenge for understanding variation in vegetation as a climate change adaptation tool spanning neighborhood to megacity scales is developing new "big data" analytical tools. We used structural equation modeling (SEM) to quantify the interacting relationships among socio-economic status data obtained from government census data, elevation and new LST and vegetation data obtained from an airborne imaging campaign conducted in 2013 for the urban and suburban areas across a series of fifteen climate zones. Vegetation systematically increased in cooling effectiveness from 6.06 to 31.77 degrees with increasing distance from the coast. Vegetation and neighborhood income were positively correlated throughout all climate zones with a peak in the relationship occurring near 25km from the coast. Because of the interaction between these two relationships, we also found that higher income neighborhoods were cooler and that this effect peaked at about 30km from the coast. These results show the availability and effectiveness of vegetation on the local climate varies tremendously throughout the Los Angeles, CA metropolitan area. Further, using the more inland climate zones as future analogs for more coastal zones, suggests that in the warmer climate conditions projected for the region the effectiveness of vegetation for regional cooling may increase thus acting as a localized negative feedback mechanism.
城市化增加了城市环境中的热量，对人类健康和福祉有许多影响。许多城市希望通过增加植被来管理气候变化，以缓解当前和未来与热相关的问题。然而，对于植被对当地降温的当前有效性和可用性有哪些影响，我们知之甚少。在这项研究中，我们确定了植被（归一化差异植被指数）、社会经济地位（邻里收入）、海拔和地表温度（LST）之间相互作用关系的变化，以确定植被为基础的表面冷却服务如何在洛杉矶大都市地区的沿海到沙漠气候梯度范围内发生变化，洛杉矶是一个拥有超过 1800 万居民的特大城市。理解植被作为跨越邻里到特大城市尺度的气候变化适应工具的变化的一个关键挑战是开发新的“大数据”分析工具。我们使用结构方程模型（SEM）来量化从政府人口普查数据中获得的社会经济地位数据、海拔和新的 LST 与从 2013 年进行的一次航空成像活动中获得的植被数据之间的相互作用关系，该活动覆盖了跨越十五个气候带的一系列城市和郊区。植被的降温效果从距海岸 6.06 度到 31.77 度系统地增加。植被与邻里收入在所有气候带中都呈正相关关系，在距海岸约 25 公里处达到峰值。由于这两个关系的相互作用，我们还发现收入较高的邻里地区较凉爽，这种效应在距海岸约 30 公里处达到峰值。这些结果表明，在洛杉矶大都市地区，植被的可用性和有效性在整个地区差异极大。此外，使用内陆气候带作为沿海气候带的未来模拟，表明在该地区预测的更温暖的气候条件下，植被对区域降温的有效性可能会增加，从而成为一种局部的负反馈机制。
