Urban expansion and its impact on urban heat island intensity: a case study of Chengdu City, China

Abstract

Studying the coupling relationship between urban expansion and urban heat island(UHI) expansion is of great significance and scientific value for the realization of healthy urbanization development. In this paper, the temperature field in Chengdu is simulated using a new generation mesoscale Weather Research and Forecast(WRF) model. Then this paper combined with remote sensing land cover products to reveal the coupling relationship between urban expansion and urban heat island effect expansion in Chengdu from 2002 to 2020 through the mean standard deviation method and the center of gravity shifting model. The results showed that: (1) From 2002 to 2020, the trend of the urban expansion and UHI expansion of Chengdu was synchronized; (2) The construction land area of Chengdu nearly doubled, 5.57%. The size and intensity of UHI expanded during the day and night. (3) During the study period, the couple relation between Chengdu's urban expansion and UHI expansion had obvious stage characteristics. From 2002 to 2011, the movement between the two was highly consistent and coupled. From 2011 to 2020, the spatial effect of construction land on the UHI weakened.