Geomorphic Network and Analysis Toolbox - GNAT

Introduction

The Geomorphic Network and Analysis Toolbox is a set of ArcGIS geoprocessing scripts used to generate Geomorphic Attributes on a Stream Network, such as NHD or NWI. It is written in Python as an ArcGIS Python Toolbox for ArcGIS 10.1.

There are three groups of tools included within GNAT: Stream Network Management tools are used to pre-process networks and include functions such as braid identification and network connectivity assessments and repair. The Geomorphic Network Analysis tools generate and summarize network-based geomorphic metrics such as confinement and sinuosity. Lastly, Utilities support the other tools in the toolbox. They are useful enough to be used as stand alone tools for other purposes.

Download

• GNAT Version 1.2 (July 24 2015)
  • Added Moving Window Analysis for Confinement
  • Minor Stability improvements

Previous Releases

Updates and Release Notes

8/19/2015

• Cleaned and Updated documentation for most tools

7/24/2015

• Released GNAT version 1.2
• Restructured Workflows
• Expanded Tool Documentation

7/14/2015

• Moved the documentation to the wiki.
• Changed references from "Riverstyles and Stream Network" to GNAT.

Tool Descriptions

These are the formal documentation pages for each tool. For information on how to work with these tools, see the Getting Started page.

Geomorphic Network Analysis Tools

These tools are used to calculate, analyze, and manage the Geomorphic Attributes derived from the Stream Network.

• Confinement
• Sinuosity and Planform
• Moving Window Analysis
• Combine Attributes

Stream Network Management

These tools are used to prepare, clean, and manage the Stream Network itself.

• Calculate Stream Order
• Build Network Topology Table
• Check Network Connectivity
• Copy Stream BranchIDs
• Find Braids In Stream Network
• Find Crossing Network Lines
• Find Network Outside Polygon
• Find Dangles and Delete Identical Features
• Generate Stream Branches
• Segmentation

Utilities

These tools support the other tools in the toolbox. They are useful enough to be used as stand alone tools for other purposes.

• Divide Polygon By Segments
• Centerline Tool (from Fluvial Corridor Tools)
• Sinuosity By Segment
• Transfer Line Attributes

GNAT Workflow

User Resources

• Getting Started: Outline of the workflow for using GNAT tools for analysis.
• Prepare Stream Network (from NHD) (Word docx document)
• Stream Network and Segmentation Guide
• Bankfull Buffer Workflow

GNAT Glossary and Terminology

Acknowledgements

GNAT is developed by Kelly Whitehead, Jean Olson, Carol Volk and Jesse Langdon of South Fork Research Inc., with input from Wally MacFarlane, Jordan Gilbert, Gary O'Brien, and Joe Wheaton of Utah State University.