The spatiotemporal heterogeneity and driving forces of surfacial thermal environment over an intensive mining region

Based on the Landsat thermal imagery, land surface temperature (LST) of the mining-intensive areas in Manlanzhuang, Qian'an, Hebei Province, China, was retrieved using atmospheric correction method. Meanwhile, the land surface disturbance type and four surface biophysical parameters including Fraction of Photosynthetic Vegetation (fPV), Soil Moisture Monitoring Index (SMMI), Enhanced Bare Soil Index (EBSI) and Normalized Difference Impervious Surface Index (NDISI) were analysed from the perspective of biogeophysical effects. Afterwards, the spatiotemporal heterogeneity of surface thermal environment was quantified and visualised by overlay analysis. To uncover the driving mechanism behind such spatiotemporal heterogeneities, the relationship between the four biophysical parameters and LST was assessed by correlation and regression analysis. The results show that the mining land had the highest LST, characterised as the severest heat island cluster. Surface disturbance types and four surface biophysical parameters drove the spatiotemporal heterogeneity of surface thermal environment, where the LST followed the order of mining land> residential land> cultivated land> forest land> water area. The single factor regression analysis indicates that fPV and SMMI had a significant negative linear relationship with the normalised LST (NLST), while EBSI and NDISI had a significant positive linear relationship with NLST. The multivariate regression analysis indicates that using the four biophysical parameters could holistically characterize spatiotemporal heterogeneity of surface thermal environment and better present the actual relationships between biophysical parameters and NLST. The regression coefficient of SMMI was larger than that of fPV, indicating surface moisture content had a stronger effect on surface temperature reduction. The regression coefficient of EBSI was larger than that of NDISI, indicating bare soil contributed more to surface warming. The findings of this study will provide a quantitative reference for the assessment and optimisation of surface thermal environment in mining-intensive regions. © 2021, Editorial Board of China Environmental Science. All right reserved.