Influence of spatiotemporal changes of impervious surface on the urban thermal environment: A case of Huai'an central urban area

Abstract

Urban heat island effect created by urbanization is to be one of the most worrisome urban environment issues, and impervious surface (IS) is the main driving factor of the urban heat island effect. Therefore, it is nesscessy to analyze the impact of IS on urban thermal environment from multiple perspectives. Using Landsat images from 2000 to 2020, we explored the spatiotemporal changes of IS area and urban heat islands, then investigated the impact of IS on LST with regression analysis, bivariate spatial autocorrelation, and deviation degree and contribution degree in Huai'an city. The results showed that (1) IS area in Huai'an CUA has increased dramatically from 2000 to 2020, moving towards the east and south, a net increase of 164.26 km2; (2) LST values were linearly positively correlated with IS abundance (ISA%), 10 increased in ISA% resulted an increase of 0.08 to 0.35 °C in LST, when ISA% is greater than 50%, the influence weakened; (3) IS had a significant positive spatial correlation with LST, the High-High type agglomeration area continued to expand and first agglomerated and then dispersed; (4) The deviation degree of LST in IS expansion area was less than that of original IS area, but IS expansion area contributed most to the urban thermal environment due to the vast region covered. The findings attribute a better understanding of the impact of impervious surface on urban thermal environment and should be helpful for city planners.