城市空间异质性对地表温度反演及感热通量估算的影响

城市热环境及感热通量是城市生态环境重要组成与关键评估参数。由于城市高度空间异质性以及三维几何结构复杂性导致遥感观测的城市地表信息受到很大干扰，由此开展的城市热环境与能量平衡研究存在较大偏差与不确定性。本研究针对这一科学问题，耦合城市微气象模型与遥感观测模型，基于高精度城市建筑与复杂地表结构数据，探讨卫星遥感观测得到的城市冠层辐射温度与城市真实地表温度之间的差异及影响机制；并通过微气象数值模型模拟城市感热通量过程，定量评估城市三维结构对基于卫星遥感数据的反演感热通量的影响，改进城市感热通量估算的参数化方案。在此基础上，以广州城区和香港九龙城区为试验区，开展城市真实完整地表温度和感热通量分布遥感反演。本研究试图构建一套充分考虑建筑结构和空间异质性的城市完整地表温度及感热通量遥感反演技术方案，为城市生态与人居环境建设提供参考依据，同时对解决城市热环境与热交换定量评估具有重要的科学意义。

Urban surface temperature and sensible heat flux are important parameters for urban ecological environment evaluation. While the geometry of vegetation and buildings limits observations by remote sensing over urban areas. This implies that remote sensing observation cannot capture the complete surface temperature, which causes a bias when this incomplete information is used for urban climate research. Thus, this study proposes to retrieve the complete surface temperature by combining a numerical model of urban climate with remote sensing observation and building data. First, we explored parameterization methods to construct a relationship between geometric and local climate variables and parameters and the difference between the complete surface temperature and radiometric temperature observed by remote sensing. Then relationships between the complete surface temperature and radiometric temperature will be developed and the complete surface temperature will be retrieved using satellite radiometric data in the thermal infrared region. Additionally, the complete surface temperature will be used to estimate the urban sensible heat flux and a parameterization method to estimate sensible heat flux using the radiometric surface temperature will also be explored. Lastly, the estimated urban complete surface temperature and sensible heat fluxes will be used to articulate guidelines on urban planning.