The code behind the collections. A collection is computed on one flow-direction grid; these are the methods that do it, released on their own so they can be run on any D8 grid. FlowDivide decides what is computed together; FlowTopo decides in what order.
Cuts a flow-direction grid of any size into whole basins and into regions that fit the memory at hand. Its output is the basin and region mask of every collection.
Serial orderings, parallel layerings and spatial partitions for D8 flow networks, computed once from the grid and reused by any drainage-order computation. The structures of the 90 m MERIT Hydro network are on Zenodo.
Point your phone’s camera at the code, then tap the link that appears.
fullhydro.org