Analysis of Seasonal Differences in Microclimate Formed in a Local Small City of Paddy Field Areas – A new approach using airborne remote sensing and CFD simulation

This paper examines the relationship between the seasonal land cover change and microclimate formed in a local small city of paddy field areas in Japan using airborne remote sensing data and CFD (Computational Fluid Dynamics) simulation. The land cover maps for three seasons, the 3D urban district model and the 3D surface temperature images are made using the airborne MSS (Multi-Spectral Scanner) data obtained in each season and GIS data in Tonami city, Toyama prefecture. These data are applied to the boundary conditions for the CFD simulation, and microclimate, including air current and air temperature distribution, are simulated for three seasons taking into account the seasonal land cover change. The simulation results are compared with the field measurement results for the microclimates in the site. These results quantitatively indicate that the control of microclimate by the paddy fields changes seasonally as its land cover changes through the year. In the summertime, the cooling effect of the paddy fields and the cool air current from the area contribute to the decrease in air temperature in the urbanized area.