Pfafstetter Numbering and the organisation of river networks

We just have accepted a paper related to the topological ordering we use inside our model JGrass-NewAGE.  This ordering derives is a generalisation of the Pfafstetter algorithm.
Once understood, it can be observed that this Pfafstetter ordering can be used to drive, for instance parallel execution of operations. But this is another story. We actually use to orderly process the basin partition in JGrass-NewAGE modules. The paper, entitled "Digital watershed partition within the NewAGE-Jgrass system" by Formetta et al.  can be downloaded from here.

Related topics are covered in posts of the Horton Machine, and particularly in the book Chapter written early this year for the British Gemorphological society. Abera's blog also contains a related post that can clarify some other issues.