Iterative Watershed Partition: An Efficient Method for Hierarchical River-Basin Extraction on Digital Elevation Models

Watershed partitioning, following a maximal vertex-cut constraint, ensures each basin is strictly isolated from its neighboring basins. This partition is composed of watershed arcs positioned between pairs of adjacent basins. When these arcs create a connected partition, applying watershed partition on an arc-graph ensures that the corresponding arcs of watershed points in the arc-graph still maintain this connected partition. This crucial property is leveraged in the proposed iterative watershed partition method for extracting hierarchical partition lines in an image. The method effectively extracts river basins from SRTM DEM data of the Indian state Uttarakhand, revealing a well-structured hierarchy of catchment basins.