Impervious surface increase over global border areas regulated by population and topography

Border areas between neighboring countries are crucial for the national and global success of sustainable development. These regions have witnessed rapid and widespread changes in land cover and use, especially the expansion of impervious surface areas (ISA). However, the global patterns and driving factors for this expansion are not well understood. We investigate ISA expansion in global borderlands by integrating high-frequency time-series satellite data, revealing that ISA has doubled between 1985 and 2020. The expansion is more pronounced in border areas with significant economic income disparities between countries, suggesting an overall attraction effect. Notably, 44 out of 310 borderlands (14%) accounted for 50% of ISA expansion over the past 36 years. Around one-third of global borderlands exhibit border-oriented development tendencies or border-prone characteristics. Our correlation and causation analyses indicate that population growth and topography are the primary drivers, with slight variations across different expansion modes. Understanding these border-prone characteristics and the underlying reasons for ISA expansion provides new empirical insights into urban sprawl, ecological environments, and sustainable development in border areas.