Study on the analysis of the cause of an urban heat island phenomenonthrough reproducing the past condition

摘要

In this study, we prepare the 1970's thermal environment database and attempt to reproduce anurban thermal environment using the three-dimensional meteorological mesoscale model (OA-SIS: Osaka University Simulation System). By analyzing the effect that changes in land coverand anthropogenic heat have on the urban thermal environment on the basis of the experimentalresults for the 1970s and the present state, we can identify the factors affecting today's risingurban temperatures. As a result, the following conclusions were drawn. Concerning the presentstate and past state air temperature difference distributions, it was confirmed that there was atemperature difference of more than 1°C over a wide area centered on the inner city at night.Concerning the result of analyzing the effects that changes in land cover and anthropogenic heatrelease have on the urban thermal environment, as for land cover, little effect could be seen inthe afternoon and the entire city area was greatly affected overall at night. As for heat release,especially at nighttime there was a large temperature change, the residential sector was affectedthe greatest, followed by the transportation sector and industrial sector. Concerning the result ofanalyzing the characteristics of spatiotemporal change related to the factors that control thetemperature effect, the effect of land cover was large in the afternoon and at night, but in Osakacity especially, at night the industrial sector on the coast and the residential sector in the innercity were greatly affected.