HEC-GeoHMS : Connectivity missing

Question

I am trying to make a simulation using HEC-GeoHMS in ArcGIS and I have encountered a problem near the final steps. In the drop-down menu HMS, when I click "Check Data", a report is being done and displayed in Notepad with the layers and information verified for eventual problems. The report returned 5 problems, regarding the river connectivity. This is the exact message: End of checking river: oid=5 - PROBLEM: connectivity missing. Though I have tried solving this by merging the rivers (as I have merged some sub basins to better match the real situation of the watershed) or by manually snapping the rivers(it wasn't the case because they were already snapped to the main river, but just in case) and still I receive the same report with these problems. The hydro network is counting 12 rivers and 5 of them have this connection problem.

Has anyone faced this issue and solved it?

Answer 1

here you may find an answer, at least form me it worked.https://web.ics.purdue.edu/~vmerwade/education/geohms.pdf

"After this process is complete, you will see new fields in both River and Subbasin feature classes that will have fields ending with “_HMS” to indicate these fields store attributes in the specified HMS units (English in thi s case). All fields that store lengths and areas will have corresponding “_HMS” fields as a result of this conversion. Check Data This tool will verify all the input datasets. Select HMS  Check Data . Confirm the input datasets to be checked, and click OK . You should get a message after the data check saying the check data is completed successfully as shown below. You can also look at the log file and make sure there are no errors in the data by scrolling to the bottom of the log file as shown below. "If you get problems in any of the above four categories (names, containment, connectivity and relevance), you can look at the log file to identify the problem, and fix them by yourself. This version of HecGeoHMS apparently gives error with river connect ivity even if the rivers are well connected. Therefore, check the data carefully, and if you think everything is OK, ignore the errors (if you get any for connectivity) and proceed."