Paper Conference

Proceedings of ASim Conference 2012: 1st Asia conference of IBPSA-China, Japan, Korea

     

A new approach to microclimate analysis using airborne remote sensing, 3D-GIS and CFD simulation

Takashi Asawa, Akira Hoyano, Tamon Yoshida, Masahito Takata

Abstract: In order to make use of local, natural and climatic factors for urban development and passive building design, an understanding of microclimate in the locations of interest is required. The purpose of the present study is to show the characteristics of microclimates formed in a small city of paddy field areas using airborne remote sensing data, three-dimensional Geographic Information System (3D-GIS), and Computational Fluid Dynamics (CFD). The proposed method for analyzing microclimate combines airborne Multi-Spectral Scanner (MSS) data and a CFD simulation based on a 3D-GIS urban district model. The first step is to identify the actual land cover conditions in selected urban and surrounding areas of Tonami city using the airborne MSS data, GIS data, and aerial photographs. MSS data observed at noon and nighttime in spring, summer, and winter are used for the analysis. Land cover distribution maps and thermal images are generated from these data, and a 3D-GIS urban district model for the CFD simulation is completed. In the second step, these data are applied to the boundary conditions of a 3D, steady, CFD simulation, and air current and air temperature distributions in the area are simulated for three seasons, taking into account seasonal changes in land cover. The relationship between the land cover and surface temperature distributions of the Tonami urbanized area is examined based on the thermal images and land cover maps. The simulation results for the summer daytime show that cold air currents from the paddy fields flow into the urbanized area along a street, contributing to the decrease in air temperature in the area. The simulation results are compared with observation data along the street, and the accuracy of the simulation is confirmed. It is revealed that the control of air temperature by the paddy fields changes seasonally as its land cover changes through the year. * Corresponding author email: asawa.t.aa@m.titech.ac.jp
Pages: 643 - 650
Paper:
asim2012_0066