Investigating the relationship between local climate zone and land surface temperature using an improved WUDAPT methodology - A case study of Yangtze River Delta, China

The concept of Local Climate Zone (LCZ) was developed to quantify the relationship between urban morphology and urban heat island (UHI) phenomenon. Each LCZ is supposed to represent homogeneous air temperature. However, there is inadequate data for verifying the air temperature differences between LCZ classes. Therefore, it is necessary to utilize alternative temperature data which allow more comprehensive assessment of the effect of LCZ on local climatic conditions. Land surface temperature (LST) acquired from satellite images can be used to establish the relationship between LST and LCZ by providing continuous data on surface temperature. This paper aims to investigate how LST represents the UHI intensity determined by using an improved method of the World Urban Database and Portal Tool (WUDAPT) to develop the LCZ map of the Yangtze River Delta (YRD) megaregion. The results show that LST in different YRD cities is generally consistent with the LCZ classes with higher LST observed in built-up LCZ classes. The diverse urban morphology and temporal vegetation variation are likely the reasons to inconsistencies in LCZ 9, and LCZ A to D. Findings of this paper provide a better understanding of how urban morphology affects local climate and more accurate delineation of LCZ classes.