基于遥感的湿热地区城市住区热环境研究

The thermal environmental problem becomes more and more serious in cities in China under the background of fast urbanization. The summer is long, the number of hot days is big, and the thermal environmental problem is severe in hot-humid region of China. It is important and necessary to study the thermal environments of urban residential areas in hot-humid region, for both mitigating urban heat island, improving living environmental quality and reducing energy consumptions of buildings and cities..The previous studies on thermal environments of residential areas are mainly based on field measurement or numerical simulation. Only one or several cases are studied, and the sample size is too small to obtain general models. The previous remote sensing studies on urban thermal environments are mainly in urban or region scale, and the few studies in residential areas scale have the problems of near-ground air temperature inversion and simplification of predictive model..Focused on hot-humid region of China, the present study is aimed to achieve the large sample observations of residential areas based on high resolution satellite remote sensing, establish the inversion model for near-ground air temperature based on field measurements and energy balance equations, and obtain the general predictive model for thermal environments of residential areas in hot-humid region of China through the inversions of surface characteristic parameters and planning and design factor. The present study is believed to provide solid bases for the design and improvement of thermal environments of residential areas in hot-humid region of China, and provide useful references for other regions as well in aspects of academic study and practical application.

随着城镇化发展，城市的热环境问题越发突出。我国南方湿热地区夏季漫长、高温日数多，城市热环境问题严峻。开展湿热地区的城市住区热环境研究，将为缓解城市热岛强度、提升居住环境质量和降低建筑与城市能耗提供重要基础。.以往基于实测和模拟的住区热环境研究，多以个别案例为对象展开，样本量小，缺乏代表性和普适性。以往的城市热环境遥感研究多为城市和区域尺度，仅有的住区尺度研究存在近地气温反演和预测模型简单化问题。.本项目立足于南方湿热地区，基于高精度卫星遥感获取大样本住区观测数据，结合实测确立以能量平衡法为基础的近地气温反演模型，再结合地表特征参量和住区规划设计因子的反演，建立普适性的湿热地区城市住区热环境预测模型。本项目的研究，将为湿热地区住区的热环境设计和优化提供重要依据，并为其他地区的相关研究和实践提供有价值的参考。

本课题以湿热地区突出的城市气候问题为背景，基于遥感和地表能量平衡，开展湿热地区城市气候的研究。局地尺度的城市气候与人们生活和建筑能耗息息相关，是城市气候研究的重要尺度，其中街区和居住区是局地尺度常见的研究对象，分别对应0.5×0.5 km和2×2 km。开展湿热地区城市局地气候研究，将为提升城市居民生活环境质量、降低城市热岛和建筑能耗以及缓解城市气候问题提供重要基础。研究内容包含：.1）遥感是大范围快速获取地表特征参量的重要手段，目前还缺乏针对城市局地气候的成套遥感方法与技术。为此，以方便获取且分辨率高的卫星遥感影像（Landsat和GeoEye-1）为主要数据源，本项目梳理地表温度等气候参数及相关规划设计因子的反演及提取方法。.2）城市地表能量平衡观测与模型验证。以湿热地区典型城市广州为对象，采用涡度相关系统技术，选择分布最多的高密度高层建筑城市局地气候分区开展夏秋两季SEB观测，掌握了湿热地区城市地表能量交换的基本特征，揭示了天气条件对城市地表能量平衡的关键性影响，验证了代表性城市能量模型LUMPS在湿热地区的适用性（Q^*和〖∆Q〗_S一致性指数超过0.95，Q_H和Q_E根均方差为36.5和42.8 W m-2）。.3）城市近地空气温湿度遥感反演方法。基于地表能量平衡提出新的城市近地空气温湿度遥感反演方法，综合第1部分建立了一套完整的高精度城市局地气候遥感技术（测试验证的地表温度、近地空气温度和水汽压遥感精度分别为1.0°C、1.0°C和2.06 hPa），为城市局地气候大样本观测和定量化研究提供科学可靠的方法。.4）城市局地气候预测经验模型。结合局地气候分区（LCZ）体系，充分运用城市局地气候遥感技术获取广州中心城区大样本（总样本量625）遥感数据，明确影响主要LCZ类型的关键规划设计因子，建立了预测性能较好的城市热岛经验模型（地表城市热岛预测误差小于0.95°C，城市热岛预测误差小于0.04°C）。本研究有力支撑湿热地区的气候适应型城市建设，并为我国其他地区及全球湿润亚热带气候区提供重要参考。