Understanding the effects of 2D/3D urban morphology on land surface temperature based on local climate zones

Summer increasingly gets hotter, which has become a common problem that threats human settlement environment and hinders urban sustainable development. The impacts of urban morphology on land surface temperature (LST) have been studied extensively, but the investigation from the local climate zones (LCZs) perspective is less concerned. We thus explored the relationship between 2D/3D urban morphology and spatial variation of LST across seasons based on LCZs by utilizing high-resolution remote sensing images and vector building data. The results showed that: (1) the spatial distributions of seasonal LSTs took a circle structure with three rings from the city center to the fringe area. In particular, the temperature showed a characteristic of "High-Low-High " in spring, autumn, and winter. However, the LSTs in the first ring were 1.4 ? and 2.2 ? higher than the second and third ring in summer, respectively. (2) The inter-LCZs differences of LST were consistent across seasons. In summer, the warmest zones were LCZ 2 and LCZ 3 with 2-3 ? higher than other built type LCZs, while the coldest zones were LCZ A and LCZ G with 4-6 ? lower than other land cover type LCZs. (3) The most influential 3D factor on LST was the mean building height with a significant cooling effect in LCZ 1, LCZ 3, and LCZ 4 in spring and autumn. Impervious surface fraction was the dominated 2D factor with a significant warming effect in all seven built type LCZs in summer.