Analysis of thermal environment in building, district, urban and regional scale and its application to Asian Megacities

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Field survey and simulation with various scales were conducted for thermal environment of Asian mega cities, and mitigation options were discussed.Building information was obtained by analysis of photographs with a fish-eye lens in field survey in Chongqing, China for calculation of thermal environmental index. This method is useful in the region where geographic information is limited. Heat environment was surveyed in Cheong-gye stream, Seoul City, which is well known as restored stream in urban area. Improvement of thermal environment was observed by this restoration work. Individual difference in thermal comfort was analyzed.Influence of atmosphere on remote sensing data was corrected to obtain surface temperature.Thermal environment of Chongqing was analyzed with applying RAMS with input of land use data from remote sensing and anthropogenic heat discharge based on energy statistics. By comparing with observed meteorological data, it was verified that built-in of a canopy model into RAMS improved the simulation results in Chongqing. Effect of future development of Chongqing with doubled population and doubled urban area was estimated by the proposed model. Temperature increase in newly developed area and existing urban area will be about 5 degree and 1 degree, respectively. Area of temperature higher than 40 degree during daytime and higher than 30 degree during nighttime will be expanded by 2.4 times and 3.7 times, respectively. Various mitigation options were predicted by this simulation.District scale simulation was conducted for Taipei. Simulation considering change of heat rejection from air-conditioner with various time showed that temperature increase due to this heat rejection is up to 1.8 degree near the building. Effect of introduction of cooling tower to improve heat environment in night time and application of water mist spray and water film on the wall with photo catalyst were evaluated.