Urban engineering insights: Spatiotemporal analysis of land surface temperature and land use in urban landscape

In the field of urban environment engineering, understanding the relationship between land surface temperature (LST) and land use land cover (LULC) is essential in rapidly growing and climatically unstable urban landscapes such as Chengdu. It helps alleviate the magnitude and intensity of Urban Heat Islands (UHIs). Toward this aim, summer and winter Landsat images were acquired in four years from 1992 to 2021 and were used to extract LULC classes, LST and three indices of the Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), and Modified Normalized Difference Water Index (MNDWI) and analyze their spatiotemporal associations. Results showed that built-up areas expanded approximately six times (820.82 Km 2 , 584.96%) from 1992 to 2021. Meanwhile, their mean LST increased in both seasons, by 9.94 degrees C in summer and by 0.95 degrees C in winter. The LST-NDBI correlation was significant and positive in both the summer and winter of the studied years (0.437 < r <0.874, p=0.00) while a very high variability was observed in the LST-NDVI (-0.835 < r <0.255, p=0.00) and LST-MNDWI (-0.632 < r <0.628, p=0.00) correlation coefficients. According to the results, NDBI can be used as a good intra- and inter -annual predictor of LST in Chengdu, especially in the context of its fast -paced physical expansion and increasing intensity of UHI.