Unveiling the evolution and driver of urban heat island in Shenzhen using multiple remote sensing techniques

The surface urban heat island (SUHI) effect is closely linked to urbanization and land-use patterns, yet its variation and evolution remains poorly understood in rapidly developing cities. This study analyzed the spatiotemporal evolution and driving factors of SUHI in Shenzhen, China, using nearly three decades of MODIS and LANDSAT remote sensing imagery. Our results revealed pronounced spatial variations in land surface temperature (LST), with urban impervious surfaces consistently warmer than vegetated areas. The SUHI effect was observed both in the day and night, showing an increasing trend over the past two decades but stabilizing in recent years. We observed that the SUHI effect was more pronounced in summer than in winter, with areas of high economic development and population density showing greater intensity. In contrast, districts with greater ecological preservation exhibited lower SUHI intensity. The SUHI effect stabilized in recent years following rapid growth during earlier urban expansion phases. Thermal patterns and energy balance in Shenzhen were influenced by urban vegetation and impervious surfaces. Correlation analysis indicated that SUHI intensity was negatively associated with leaf area index and surface evapotranspiration, and positively associated with surface albedo. By integrating multi-source and multi-temporal remote sensing data, this study enhances understanding of urban thermal dynamics and supports data-driven strategies for sustainable urban planning and climate adaptation.