Generate Stream Branch Tool

This tool dissolves the line network based on GNIS Name and Stream Order to create Stream Branches in the Network. Stream Branches are then used for segmenting the network by the longest, continuous stretches of stream.

Usage

For the entire Stream Branch workflow, see Stream Network and Segmentation

Parameters

Input Stream Network (with Stream Order)

Stream network with Stream Order Attributes (from stream order tool).

Input Junction Points (Optional)

Use the Junction Points Output from the Stream Order tool to split branches at Stream Order Convergences. Otherwise, the tool will dissolve all stream order segments that converge with the same stream order value.

Stream Name Field

Attribute Field with GNIS_Stream Name. Not all segments need to have a stream name - the tool will use Stream Order for segments without a stream name.

Stream Order Field

Attribute Field that contains the Stream Order for each line feature.

Output Line Network with Branch ID

File GDB polyline feature class. The tool will overwrite existing dataets.

Dissolve Output by BranchID? (Optional)

• Checked: The output stream network will contain all features dissolved by the BranchID. Feature Attributes will be dropped due to the dissolve.

• Unchecked: The output stream network will retain its original features and attributes, with the addition of the BranchID field.

Scratch Workspace (Optional)

You may use:

1. Create a new file GDB to save temporary processing files (useful for debugging).
2. If a workspace is not designated, the tool will use the "in_memory" workspace. You will not be able to view the temporary files, but the processing speed will be much faster.

Technical Background

This tool uses the following methodology:

1. Input Line Features are selected by GNIS_name, then Dissolved by GNIS_name.
2. The Selection is switched, then Dissolved by Stream Order, if present
3. The Outputs from 2 and 3 are merged.
4. Split Line at Point using the input Junction Points > This fixes the issue where two tributaries with the same stream order (and no GNIS) are dissolved together. This mainly occurs at the headwaters (i.e. Stream order = 1).
5. Add a unique Id field (BranchID) to identify each branch
6. The Original input is intersected with the Branches layer, if the output is not to be dissolved. Otherwise, the output is simply copied over from the Branches layer.

Troubleshooting and Potential Issues

• This tool is currently set up around a specific workflow for generating stream branches. Skipping a workflow step or clean up process may result in erroneous results or tool failure.

Versions and Refinement

• 1.3 Initial Version
  • Fixed Issues with the presence of fields when network is dissolved.
  • Added option for not dissolving the output by Stream Branch.

Future Development

• Enable Multiple (tiered) attributes to dissolve by, with stream order as the last attribute.
• Enable "Use Longest Segments" option to increase branch length at stream order convergences.