Lesson 16: Introduction to the USGS Hydrolink Tool
This video provides basic information about the HydroLink Tool to get you up and running with the basic tool capabilities.
See other videos and documentation for additional details and tips.
To get started with the HydroLink Tool, referenced as HLT, go to maps.usgs.gov/hydrolink in Chrome or Firefox and login using your ArcGIS Online Account.
If a user does not already have an ArcGIS Online account, USGS staff can request an account.
After signing in, any feature services in your ArcGIS Online Account will display in the HLT dashboard.
Note that only data added by the tool will fully function in edit mode.
Add your data by selecting “Add Shapefile” or “Add CSV”.
The “Add CSV” option also handles Excel Spreadsheets.
Ensure your input data meet the outlined requirements, specify a name for your data, and the directory of your file
and click the upload button.
In the dashboard select “Edit” for the newly uploaded data.
In edit mode the view defaults to the extent of the data with a satellite basemap.
You will notice eight fields showing in the table at the bottom of the screen.
These fields were added to the data upon upload and will be populated with NHD reach identifiers
and HydroLinked data as records are processed.
Before HydroLinking your data, we recommend the following set-up to help improve your experience.
First click on the options symbol in the upper right of the table and select “Show/Hide” columns.
Check those fields that will help you identify with site locations.
In this example, I will select site id and stream name.
You also have the option to change the basemap using “Switch Basemap” in the upper left of the map.
The satellite imagery will help you identify with a site location, but sometimes having labels or topography as a basemap will also be helpful.
Select a point to process by clicking on a point in the map or by clicking on the row in the table.
We recommend selecting points using the table to help in tracking progress.
Notice the point corresponding to the selection is now highlighted.
Zoom to the point using the mouse scroll wheel or the plus and minus buttons in the upper left of the map.
As you zoom in, the edit mode will be enabled (Editor Status is displayed below the map) and NHD layers will appear.
You will see the NHD High Resolution and NHD+ Medium Resolution layers in the map legend to the right.
Ensure that the point is representative of your sample site and or other type of feature to be linked,
by using a combination of your personal knowledge of the site, the site description in the table, and the aerial imagery.
Move the point to the correct location if needed by first clicking on the point.
A hand appears, allowing you to click and hold to drag the point to the correct location.
Note, it is not always appropriate for the point to be overlaying the NHD layers.
When it is appropriate to link a point to both versions of the NHD click the Locate button on the right,
then click near the High Resolution line that represents the appropriate linkage.
Squares appear on the NHD layers to visually represent the suggested linkages.
Suggested latitude, longitude, reach codes and measures are also displayed on the right in the “Selected Point Coordinates” box.
If needed, the linkage process can be repeated to adjust suggested values.
If the medium resolution linkage needs to be adjusted, unselect the “NHD+ High Resolution”,
click Locate, and click near the correct location on the Medium Resolution line.
Reselect the NHD+ High Resolution to once again show both linkages.
If there are no appropriate lines to link the point to, in one or both NHD datasets then select No Reach for this Point.
When the appropriate selections are made click Update.
At this time the verified location and information about the linkage to NHD is written into the table below.
After “Update” is selected, the tool advances to the next point in the table.
When all records are linked return to the dashboard using the button in the upper right.
Export the updated data as a shapefile by clicking on “Export”.
Your data can now be documented and released.
We recommend making your data available in the National Hydrography Dataset Linked Data Registry,
where other users and applications can find and use your newly HydroLinked data.
For more information contact Mike Tinker.
Also, as you use the HydroLink Tool, if issues with the NHD High Resolution are detected
please report them using the NHD Markup Application at edits.nationalmap.gov/markup-app.
This concludes lesson 16.