This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via obj...This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via object-based image analysis(OBIA)using Geoeye-1 at 3-m resolution(Las Vegas)and QuickBird at 2.4-m resolution(Phoenix).Spatial autocorrelation(local Moran’s I)was then used to test for spatial dependence and to determine how clustered or dispersed points were arranged.Next,we used Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)data acquired over Phoenix(daytime on 10 June and nighttime on 17 October 2011)and Las Vegas(daytime on 6 July and nighttime on 27 August 2005)to examine day-and nighttime LST with regard to the spatial arrangement of anthropogenic and vegetation features.Local Moran’s I values of each land-cover type were spatially correlated to surface temperature.The spatial configuration of grass and trees shows strong negative correlations with LST,implying that clustered vegetation lowers surface temperatures more effectively.In contrast,clustered spatial arrangements of anthropogenic land-cover types,especially impervious surfaces and open soil,elevate LST.These findings suggest that city planners and managers should,where possible,incorporate clustered grass and trees to disperse unmanaged soil and paved surfaces,and fill open unmanaged soil with vegetation.Our findings are in line with national efforts to augment and strengthen green infrastructure,complete streets,parking management,and transit-oriented development practices,and reduce sprawling,unwalkable housing development.展开更多
基金This research study is supported by a NASA-funded project(NASA award number NNX12AM88G)titled"Understanding Impacts of Desert Urbanization on Climate and Surrounding Environments to Foster Sustainable Cities Using Remote Sensing and Numerical Modeling."This material is also based upon work supported by the National Science Foundation under grant number BCS-1026865,Central Arizona-Phoenix Long-Term Ecological Research(CAP LTER),and under NSF award number SES-0951366 and SES-0345945,Decision Center for a Desert City(DCDC).
文摘This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via object-based image analysis(OBIA)using Geoeye-1 at 3-m resolution(Las Vegas)and QuickBird at 2.4-m resolution(Phoenix).Spatial autocorrelation(local Moran’s I)was then used to test for spatial dependence and to determine how clustered or dispersed points were arranged.Next,we used Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)data acquired over Phoenix(daytime on 10 June and nighttime on 17 October 2011)and Las Vegas(daytime on 6 July and nighttime on 27 August 2005)to examine day-and nighttime LST with regard to the spatial arrangement of anthropogenic and vegetation features.Local Moran’s I values of each land-cover type were spatially correlated to surface temperature.The spatial configuration of grass and trees shows strong negative correlations with LST,implying that clustered vegetation lowers surface temperatures more effectively.In contrast,clustered spatial arrangements of anthropogenic land-cover types,especially impervious surfaces and open soil,elevate LST.These findings suggest that city planners and managers should,where possible,incorporate clustered grass and trees to disperse unmanaged soil and paved surfaces,and fill open unmanaged soil with vegetation.Our findings are in line with national efforts to augment and strengthen green infrastructure,complete streets,parking management,and transit-oriented development practices,and reduce sprawling,unwalkable housing development.
基金Project Vivafunded by the U.S. Environmental Protection Agency(RD83479801)the National Institutes of Health(K24 HD069408,R37 HD 034568, P01 ES009825)
文摘[背景]对成人的研究已表明,空气污染暴露与血压升高有关。[目的]研究产前暴露于空气污染物与新生儿收缩压(SBP)之间的关联。[方法]研究马萨诸塞州波士顿市地区出生前队列中的1 131对母婴,计算各妊娠期以及产前2~90 d在固定监测点测量的时间分辨的细颗粒物(≤2.5μm;PM2.5)、炭黑(BC)、一氧化氮(氮氧化合物)、二氧化氮(NO2)、臭氧(O3)和一氧化碳(CO)的平均暴露水平,并估计居住点水平上时空分辨的PM2.5和BC暴露。用自动仪器测量平均年龄为(30±18)h新生儿的收缩压,并使用混合效应模型检验空气污染物暴露与SBP之间的关联,分析中考虑了测量环境、孩子的出生体重、母亲的年龄、种族/族裔、社会经济地位、妊娠后期BP以及时间趋势。估计值表示为每一种污染物每增加一个四分位数间距(IQR)所致的SBP差异。[结果]在妊娠后期,较高的平均PM2.5和BC暴露与较高的SBP有关联[例如,居住地90 d BC平均值增加0.32μg/m3与SBP升高1.0(95%CI:0.1~1.8)mm Hg有关联]。相比之下,O3与SBP呈负相关[例如,产前90 d O3升高13.5×10-9与SBP降低2.3(95%CI:-4.4^-0.2)mm Hg有关联]。[结论]妊娠后期暴露于PM2.5和BC与新生儿SBP呈正相关,而O3与SBP呈负相关。纵向随访能够评估这些研究结果对这些新生儿随之的童年期和成年期的健康影响。
