Research on spatio-temporal dynamics and spatial association with thermal environment of impervious surfaces in Chang-Zhu-Tan urban agglomeration

In order to deeply explore the spatial relationship and spatial differentiation characteristics between the impermeable water surface and surface temperature in cities.Based on remote sensing image data, the impermeability of Chang-Zhu-Tan urban agglomeration was extracted using the Normalized Difference Impervious Surface Index (NDISI).The Land Surface Temperature (LST) was retrieved through atmospheric correction method to quantitatively analyze the spatio-temporal variation patterns of impervious surfaces and urban thermal environment.A bivariate spatial auto-correlation model was further employed to investigate the spatial relationship between impervious surfaces and thermal environmental effects.The results demonstrate: It is influenced by factors such as elevation, slope, population density, economic development level, and planning policies from 2000 to 2020, the impervious surface area in the urban agglomeration increased significantly by 787.6 km², showing spatial distribution patterns consistent with urban built-up areas characterized by "large-scale concentration and small-scale dispersion".The thermal field grade of Chang-Zhu-Tan urban agglomeration was mainly in the medium-temperature zones, with limited low-temperature and high-temperature areas, though the high-temperature zones exhibited fluctuating expansion trends.The impervious water surface in the Chang-Zhu-Tan urban agglomeration had a significant positive spatial correlation with the thermal environment effect.The spatial aggregation types were mainly high-high aggregation and insignificance.High-high aggregation was distributed in the middle of urban agglomerations and spreaded outwards.The findings can provide a reference for alleviating the urban heat island effect and optimizing the territorial spatial layout in the Chang-Zhu-Tan urban agglomeration.