Analysis of Thermal Environment in a Street Canyon Using Thermal Images

大多数针对模拟城市气候的研究都是基于假设城市冠层为粗糙度的考虑，因此很难获得适合城市冠层的热平衡。这个问题导致了我的论文，这篇论文的重点是使用一个新的指数来调查所有的城市表面，这个指数可以在城市发展规划期间评估城市热环境。利用遥感和GIS数据对所有城市地表的实际情况进行调查，验证了采用该指数的效果。此外，还开发了一种热平衡算法，可以模拟这些表面，从而构建城市热图像。(1)定义了一个基于感热通量的新指标“热岛势”（heat island potential， HIP），以表达城市区域内各类型区域的热特征，如空间形态和材料。建立用于热平衡模拟的粒子系统所需的最佳网格尺度为1 m.2)开发了一种实用的、基于计算机性能的方法，用于预测所有城市表面的表面温度分布。在假设周围环境的表面温度分布与空气温度相等的情况下，模拟了各个粒子系统的热平衡。在得到所有城市表面温度分布结果的基础上，模拟来自周围环境的长波辐射，从而可以再次模拟每个粒子系统的热平衡，并在两次迭代后优化该反馈系统。通过将计算结果与遥感观测到的实际地表温度分布进行比较，验证了基于GIS数据开发的算法的有效性。

Most studies directed at simulating an urban climate have been based on the consideration that an urban canopy layr can be assumed roughness, and therefore, obtaining a suitable heat balance for an urban canopy layr has been difficult. This problem led to my thesis, which is focused on investigating all urban surfaces using a new index that can evaluate an urban thermal environment during urban development planning. The effects of employing the index are verified using remote sensing and GIS data to investigate the actual conditions of all urban surfaces. In addition, a heat balance algorithm is developed which can simulate these surfaces such that urban thermal images can be constructed.1)A new index based on sensible heat flux, called "heat island potential(HIP)", was defined to express the thermal characteristics of each type of region contained in an urban area, i.c., spatial forms and materials. The optimum mesh scale required to set up an system of particles used to perform the heat balance simulation was found to be 1 m.2)A practical, computer-performance-based method was developed for predicting the surface temperature distributions of all urban surfaces. On the assumption that the surface temperature distributions of surroundings is equal to air temperature, the heat balance of each particle system was simulated. Based on results providing the temperature distribution of all urban surfaces, the long wave radiation from the surroundings was simulated such that the heat balance of each particle system could be simulated again, with this feedback system being optivized after two iterations. The effectiveness of the algorithm developed based on GIS data was verified by comparing calculated results with actual surface temperature distributions observed by remote sensing.