Matlab-based tool for drainage network ordering by horton and hack hierarchies

This work presents a new MATLAB-based tool designed for network extraction and drainage network orderings by Horton and Hack hierarchies. Most GIS software offers only topological network orderings, based on joining segments, such as Stahler or Shreve, providing segments between junctions but not entire streams. Differently, Hack and Horton orderings allow organizing a drainage network in a hierarchy, identifying the parent segment over the child segment, giving as a result a drainage network where the value of a river remains unchanged from the mouth upstream to the headwater, allowing extracting entire streams. Horton and Hack hierarchies ease the interpretation of a drainage system compared to Strahler and Shreve. To extract the drainage network, this tool uses TopoToolbox 2 functions, to compute the prior steps of the channel network extraction and channel network ordering processes, and develops new functions. To sort a network, this tool allows selecting the parameter that defines the network hierarchy. This parameter is the so-called hierarchy attribute and could be the distance upstream, which refers to the distance between a junction upstream to the headwater, or the upstream accumulation, which is the accumulation at the junction. In addition to these mandatory parameters, the tool offers a set of optional parameters which turns it into a competitive alternative to generate a highly tailored ordered drainage network. The continuous channel network provided by the tool facilitates the use of other multiple applications for landscape analysis, such as the extraction longitudinal profiles or basin analysis through geomorphic indices.http://dx.doi.org/10.4995/CIGeo2017.2017.6607