Comprehensive inventory of landslide relics in the three gorges reservoir area: spatial distribution and controlling factors

The Three Gorges Reservoir Area (TGRA) is a region highly prone to geological disasters, yet fragmented databases have limited a systematic understanding of landslide patterns. To address this, we established the most comprehensive spatial database of landslide relics in the TGRA through multi-source data fusion and targeted field validation. Investigations on representative relics in the high-density confirmed an interpretation accuracy of > 90%. Based on this, a total of 10,645 landslide relics were inventoried, covering 1,339.68 km², with their size-frequency following a log-normal distribution. Through rigorous statistical analyses, including multicollinearity tests, kernel density estimation, and probability distribution fitting, this study reveals dominant controlling factors: the 400–800 m elevation zone, on slopes of 35°–45°, and on northwest-, west-, and north-facing aspects. The sandstone and mudstone interbedded with shale and coal seams (SMSC) formation is the most susceptible stratum (56.5%). Proximity to structures is key, with over 65% of landslides located within 2000 m of faults and rivers. Road networks also show a strong influence. These findings deepen the scientific understanding of long-term landslide development patterns and provide a reliable data foundation for regional susceptibility assessment, risk zoning, and disaster mitigation.