NHDPlus Versioning
NHDPlusV2nn_<dd>_<VPUid>_componentname_<vv>
or
NHDPlusV2nn_<dd>_<VPUid>_<RPUid>_componentname_<vv>
where:
V2nn is Version (2) and subversion (nn) of the NHDPlusV2 data model
dd is the drainage area identifier
VPUid is the VPU identifier
RPUid is the RPU identifier
Componentname is the name of the NHDPlusV2 component contained in the file
vv is the data content version, 01, 02, ... for the component
Additional information about the NHDPlusV2 content and distribution format
can be found in the "NHDPlusV2 User Guide" (182 pp, 4.3 MB, About PDF)
Both the data model schema and the data content are versioned. NHDPlus download .Z (zip) files each contain the version information in the filename in the format shown above. Each component can be versioned and distributed without the need to re-release all components. For example, at any given time, both NHDPlusV21_SR_09_NHDPlusCatchment_01.7z and NHDPlusV21_SR_09_NHDSnapshot_04.7z might be available for download. In this example, the NHDPlusCatchment file has schema version 21 and data content version 01 while the NHDSnapshot file has schema version 21 and data content version 04.
The NHDPlus download site contains the most recent version for each component. When a change in NHDPlus affects more than one component, the new version of all affected components are made available at the same time. Therefore, users can be assured that all components on the download site, regardless of their indicated versions, are compatible with each other.
Additional information about the NHDPlusV2 content and distribution format can be found in the NHDPlusV2 User Guide (182 pp, 4.3 MB).