Note that these solutions rely on pre-existing attribution within the WBD (HUC12, ToHUC, HUTYPE fields in the WBDHU12 feature table) to determine connectivity among WBDHU12 polygons. For performance reasons these tools build an ancillary table. These tools must also include checking capability to flag inconsitencies in the coding (many of which have been recently fixed, thanks to these tools).
Potential points of conversation
(once initial code/method content documented a bit)
- comparison/improvement of methods
- any typical analyses that we could build on top of these tables? might be a nice place to start and use this to build to more complex version for NHD itself (w/ftype, divergences, etc)
- any feedback/recommendations for NGTOC out of this stuff?
A general request or idea is to develop this table or code for the highest (that is, 12-digit HUC) and then have some helper code or even just usage logic for inferring all coarser levels of HUC.