Gapped or Branched Attribute Check

Gapped or branched attribute tool

The gapped or branched attribute tool is a two part process. It checks NHDflowline features for gaps or branching in GNIS Names by using GNIS ID’s.

The second part checks NHDFlowline features for gaps or branching in reachcodes.

Add Tool Box

ArcToolbox:NHD ToolsDouble click on gapped_or_branched_attribute_check

Browse to Select Feature Class

Select NHDFlowline in your personal geodatabase (mdb)Add

Use drop down to select Character Field “GNIS_ID”OK

Script dialog box:Successful completionClose

Output – Same folder as your pgdb“1d_gob_gnis_id.dat” and“errnodes”

Note: If you do not have any errors the table will not be created

Note: You will not be able to see the .Dat file in Windows Explorer.

Make GNIS fixes before running ReachCode check.When you run ReachCode check it will overwritethe GNIS errnode coverage.

ArcMap: Add Data

Files errnodes and 1d_gob_gnis_id.dat are in same folder as your pgdbAdd

Right click on 1d_gob_gnis_id.datJoins and RelatesRelate

Populate table as shown belowOK

Right click on 1d_gob_gnis_id.datOpen attribute table

Select recordOptions, Related Tables, 1d_gob_gnis_id:NHDFlowline

Associated NHDFlowline Records are selected

Change point symbology to size 15 on errnodes point file

Double click on point symbol

Zoom to selected records

In this case the GNIS ID (and GNIS Name) is disconnected

Example: Error from 1d_gob_gnis_id table……..In this case the GNIS ID (and GNIS Name) is branched

Resolve all errors in table

ArcToolbox:NHD ToolsDouble click on gapped_or_branched_attribute_check

Browse to Select Feature Class

Select NHDFlowline in your personal geodatabase (mdb)Add

Use drop down to select Character Field “ReachCode”OK

Script dialog box:Successful completion

Output – Same folder as your pgdb“1d_gob_reachcode.dat” and“errnodes”

Close

Note: If you do not have any errors the table will not be created

Add “1d_gob_reachcode.dat” and “errnodes”

Right click on 1d_gob_reachcode.datJoins and RelatesRelate

Populate table as shown belowOK

Right click on 1d_gob_reachcode.datOpen attribute table

Select recordOptions, Related Tables, 1d_gob_reachcode:NHDFlowline

Associated NHDFlowline Records are selected

Zoom to selected records

In this case the ReachCode is disconnected

Resolve all errors in table