Reference

SBN functions Functions for generating and woking with SBNs
sbn_create()	Create SBNs
sbn_change_dir()	Change the upstream/downstream direction of an SBN
sbn_down_dir()	Convert to a downstream directed network
sbn_get_downstream()	Find all downstream nodes
sbn_get_upstream()	Find all nodes upstream of a given node
sbn_get_outlet()	Find river mouth node
sbn_get_hw()	Find all headwater nodes
sbn_strahler()	Get node strahler order
sbn_to_mtx()	Convert network to various adjacency/distance matrix formats