Study on the spatial heterogeneity of urban heat islands and influencing factors

Conflicts between urban expansion and urban heat islands (UHIs) are increasing markedly, because of accelerated urbanization, and it is urgent to mitigate the UHI effect. In this study, we explored the spatial heterogeneity of UHIs from a neighborhood perspective via inversion of land surface temperature (LST) based on Landsat-8 remote sensing image data and using local Moran's I; the central urban area of Jinan City was selected as the study area. Furthermore, by constructing a system of urban spatial structure indicators and adopting methods such as correlation coefficient analysis and spatial econometric modeling, the factors influencing UHI were further revealed. The results showed that (1) There was spatial heterogeneity of the UHI in the central urban area of Jinan. The High-High cluster was mainly distributed in the north of the central urban area of Jinan; the LowLow cluster was primarily distributed in the south of the central urban area of Jinan and the waters. Agglomeration distribution approximately coincided with heat island distribution. (2) The correlations between urban spatial structure indicators and LST in different dimensions were generally high and varied significantly. The two-dimensional and three-dimensional indicators all showed a highly significant positive relationship with LST. The mean and standard deviation of the DEM and absolute building height in the one-dimensional indicators were both negatively and significantly correlated with LST. (3) Building height standard deviation had a significantly positive spillover effect on the LST of the neighboring areas; this spillover effect was greater than the direct effect on these regions.