局地气候区与昼夜城市热岛效应的耦合关系研究

针对局地气候区框架下城市地表热环境昼夜差异研究的不足,本文基于机载LiDAR、IKONOS-2等多源遥感数据实现了局地气候区分类,重点分析了局地气候区与城市地表温度之间的响应关系及其昼夜差异.研究结果表明局地气候区类型地表温度存在显著的昼夜差异.在白天,大型低层建筑区LCZ 8地表温度最高,水体LCZ G地表温度最低.在夜间,裸土／沙土LCZ F为最冷的局地气候区,而水体LCZ G呈现了最高的地表温度.随建筑高度的升高,紧凑建筑类型区和开敞建筑类型区白天地表温度呈现下降的趋势,而夜间则表现出相反的规律.局地气候区类型的热属性在夜间(85.8％)比白天(79.5％)更容易区分.不论白天与夜间,开敞高层建筑区LCZ 4和水体LCZ G分别为建筑类型区和土地覆盖类型区中与其他局地气候区地表温度区分更明显的类型.

Coupling between local climate zones and diurnal urban heat island effect

Given that there is very limited knowledge about how urban thermal environment varies diurnally,we first classified Local Climate Zones (LCZs) based on multi-source remote sensing data such as airborne LiDAR and IKONOS-2,and then investigated the responses of LCZs to diurnal Land Surface Temperature (LST).The results suggested that there was significant diurnal variability in LST among LCZs.During the daytime,the warmest and coolest zones were large low-rise buildings (LCZ 8) and water (LCZ G),respectively.At night,bare soil or sand (LCZ F) obtained the lowest LST,while the warmest zone was water (LCZ G).With the increasing of building height,daytime LST related to compact and open built-up types tended to decrease,and an opposite trend was observed at night.LCZs were differentiated better at night than during daytime.Moreover,regardless of day and night,open high-rise built-type (LCZ 4) and LCZ G were the most differentiated zones for built-up and land cover types,respectively.