Ecosystem services and urban heat riskscape moderation: water, green spaces, and social inequality in Phoenix, USA
Ecosystem services and urban heat riskscape moderation: water, green spaces, and social inequality in Phoenix, USA
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DOI：
10.1890/10-1493.1
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发表时间：
2011-10-01
影响因子：
5
通讯作者：
Martin, Chris A.
中科院分区：
文献类型：
--
作者：
Jenerette, G. Darrel;Harlan, Sharon L.;Martin, Chris A.
城市生态系统受到高温-极端高温事件，长期炎热的天气，或两者-通过本地和全球气候过程之间的相互作用。城市植被可以提供冷却生态系统服务，尽管在利用这一服务减少极端气候的生物物理和社会动态方面存在许多知识空白。为了更好地了解城市植被冷却模式，潜在的水资源需求，以提供这些服务，以及居民区之间的差异获得这些服务，我们评估了三十年（1970-2000年）的土地表面特征和居住隔离的收入在凤凰城，亚利桑那州，美国大都市地区。我们开发了一种生态系统服务权衡方法来评估城市热风险景观，定义为风险暴露的空间变化和潜在的人类对极端高温的脆弱性。在这一地区，植被提供了近25摄氏度的表面冷却相比，裸露的土壤在低湿度的夏季;这种服务的幅度是强烈耦合到空气温度和蒸汽压赤字。为了估计与陆面冷却相关的水分损失，我们采用了一个表面能量平衡模型。我们的初步估计表明，2.7毫米/天的水可用于在凤凰城地区的夏季提供冷却生态系统服务。2000年，这些生态系统服务的可用性和相应的资源使用需求与社区收入呈强正相关。然而，在获得服务方面的经济分层是最近的发展：1970年没有观察到植被-收入关系，到2000年，相关性明显增加的趋势很明显。为了通过增加植被和蒸发冷却来减轻极端高温风险的邻里不平等，需要大幅度增加区域用水。总之，这些结果表明，有必要对利用生态系统服务缓解极端气候的效益、成本、空间结构和时间轨迹进行系统评估。增加植被是缓解城市地区区域气候变化并同时提供多种生态系统服务的一种策略。然而，植被具有经济，水和社会公平的影响，这些影响在社区之间差异很大，需要通过明智的环境政策进行管理。
Urban ecosystems are subjected to high temperatures-extreme heat events, chronically hot weather, or both-through interactions between local and global climate processes. Urban vegetation may provide a cooling ecosystem service, although many knowledge gaps exist in the biophysical and social dynamics of using this service to reduce climate extremes. To better understand patterns of urban vegetated cooling, the potential water requirements to supply these services, and differential access to these services between residential neighborhoods, we evaluated three decades (1970-2000) of land surface characteristics and residential segregation by income in the Phoenix, Arizona, USA metropolitan region. We developed an ecosystem service trade-offs approach to assess the urban heat riskscape, defined as the spatial variation in risk exposure and potential human vulnerability to extreme heat. In this region, vegetation provided nearly a 25 degrees C surface cooling compared to bare soil on low-humidity summer days; the magnitude of this service was strongly coupled to air temperature and vapor pressure deficits. To estimate the water loss associated with land-surface cooling, we applied a surface energy balance model. Our initial estimates suggest 2.7 mm/d of water may be used in supplying cooling ecosystem services in the Phoenix region on a summer day. The availability and corresponding resource use requirements of these ecosystem services had a strongly positive relationship with neighborhood income in the year 2000. However, economic stratification in access to services is a recent development: no vegetation-income relationship was observed in 1970, and a clear trend of increasing correlation was evident through 2000. To alleviate neighborhood inequality in risks from extreme heat through increased vegetation and evaporative cooling, large increases in regional water use would be required. Together, these results suggest the need for a systems evaluation of the benefits, costs, spatial structure, and temporal trajectory for the use of ecosystem services to moderate climate extremes. Increasing vegetation is one strategy for moderating regional climate changes in urban areas and simultaneously providing multiple ecosystem services. However, vegetation has economic, water, and social equity implications that vary dramatically across neighborhoods and need to be managed through informed environmental policies.