Integrating topographic characteristics to construct lake and catchment topology on the Tibetan Plateau

Study region: The Tibetan Plateau, the Third Pole of the world. Study focus: Accurate lake–catchment topological relationships are essential for hydrological modeling in endorheic systems. Traditional depression-filling methods often misclassify real lake basins as artificial depressions, creating incorrect connectivity. Many datasets also suffer from temporal mismatches between lake extents and digital elevation models, reducing reliability. To overcome this, we developed a lake-oriented algorithm that preserves terrain integrity while correctly identifying true endorheic basins. Lake boundaries are directly extracted from the Shuttle Radar Topography Mission digital elevation model circa 2000, ensuring full temporal consistency between lakes and topography. New hydrological insights for the region: We produced the first temporally consistent lake–catchment network for the Tibetan Plateau as of 2000, containing 3985 lakes. Of these, 3743 are endorheic and 242 are exorheic. Lakes are categorized as 3764 starting, 19 middle, and 3673 terminal nodes, with 3471 serving simultaneously as both starting and terminal lakes. Our method significantly improves topological accuracy by eliminating errors from misclassified depressions and timing mismatches. This 2000 baseline offers a robust reference for tracking post-2000 hydrological changes driven by climate change and provides a transferable framework for studying water system evolution in high-altitude regions experiencing rapid environmental change.