1994 Fiscal Year Final Research Report Summary
Analysis of Thermal Environment in a Street Canyon Using Thermal Images
| Project/Area Number |
05650553
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Architectural environment/equipment
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
HOYANO Akira Tokyo Institute of Technology Environmental Physics and Engineering, Professor, 大学院・総合理工学研究科, 教授 (50108213)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Street canyon / Thermal image / Airborne MSS / Surface temperature distributions / Long wave radiation / Heat island potential(HIP) / GIS data / GISデータ |
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| Research Abstract |
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.
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