基于局地气候分区的城市热环境分析

局地气候分区(local climate zone, LCZ)是一种用于城市热岛研究的地表分类系统框架．本文基于卫星遥感影像、建筑物矢量等多源数据，开展了北京市中心城区局地气候分区分类制图，探讨了不同LCZ类型的热特征及季节差异:1）根据城市建筑矢量、地物覆盖分类数据，利用分层次分类方法构建研究区LCZ地图；2）利用Landsat 8卫星遥感影像和辐射传输方程法，反演得到研究区逐月地表温度数据；3）结合LCZ地图和多时相地表温度数据，分析不同局地气候分区各月份及季节间的热表现及差异．结果表明:研究区建筑以中低层为主，且多为开阔类型，自然地表覆盖中低植被区LCZ D占主要比例；LCZ 1-3密集建筑类型较其他建筑类型地表温度更高， 且随着建筑高度的降低温度依次增加，除水体外，LCZ A/B 林区是所有类型温度较低的区域；夏季各LCZ分区之间温度差异显著，7月份热岛强度达到全年最大值．研究结果能够为城市规划设计提供参考，助力于城市的可持续健康发展． 

Urban thermal environment analysis by local climate zone in Beijing

Local climate zone(LCZ) is a classification scheme to study urban heat island effect．Multi-source data were used for local climate zone mapping in Beijing. The thermal characteristics and seasonal differences in different LCZ types were discussed．A hierarchical classification method was developed to construct the local climate zone map．Radiation transfer equation method was applied to Landsat 8 satellite remote sensing images to retrieve monthly land surface temperature．Thermal behavior and differences in local climate zones were analyzed for each month using local climate zone map and multi-temporal land surface temperature data．The buildings in Beijing are mainly of medium and low-rise, and most are open types．Local climate zone D of the middle and low vegetation areas occupied the majority of natural land cover．The compact-type built types (local climate zone 1-3) were found to generally have higher surface temperature than other types. Land surface temperature of LCZ 1-3 increased with the decrease of building height．The forest areas of local climate zone A/B showed the lowest temperature except water bodies．There were significant differences in surface temperature for each local climate zone type in summer．Urban heat island intensity reached the highest value in July．The present work can provide reference for uban planning and design and contribute to the sustainable and healthy urban development.