Characterizing the spatio-temporal dynamics of NTL-derived anthropogenic intensity around urban lakes in China

Urban lake shore zones represent a highly sensitive interface where urban expansion interacts with lacustrine ecosystem functioning, and understanding nearshore anthropogenic intensity and its long-term evolution is crucial for sustainable urban planning and lake-shore management. However, long-term and spatially comparable assessments of nearshore anthropogenic intensity remain scarce at the national scale. To address this gap, we focus on urban lakes in China and use the Prolonged Artificial Nighttime-light Dataset to characterize nearshore anthropogenic intensity and its evolution. Specifically, we analyze nearshore nighttime light (NTL) dynamics from four aspects: intensity, directional structure, temporal change, and development trajectory. Taking the year 2020 as a reference baseline, nearshore NTL of China’s urban lakes was dominated by medium to high levels (1000–5000: 62.61%; median: 3750.04). Waterbody-type comparison further revealed stronger and faster-increasing nearshore NTL around non-reservoir lakes than around artificial reservoirs. In contrast, directional concentration was generally weak (mean = 0.18), with strong directional asymmetry observed in only about 5% of lakes. Over 1990–2020, nearshore NTL increased for most lakes (mean change rate = 62.29), with 81.93% of lakes showing medium or higher growth rates and extremely high increases concentrated in megacities and core urban agglomerations. Furthermore, clustering analysis identified six trajectory types, which were further summarized into persistent growth, multimodal fluctuation, and inverted-U patterns, with growth-oriented trajectories accounting for 84.88% of lakes. Overall, this study reveals the spatial pattern and multi-decadal evolution of nearshore human development intensity around China’s urban lakes, providing a robust basis for large-scale diagnosis and differentiated lake-shore management.