aouazad / crosssections_python

Python script and tools to compute cross-sections along a streamline in python and ArcGIS.

Cross-Sections (crossSections_05262016.py)

Synopsis

This [script] (crossSections_05262016.py) was developed to automate the process of drawing cross-sections through stream centerline using ArcGIS. The cross-sections are perpendicular to the streamline while within the channels banks, then become perpendicular to the valley walls once out of the banks.

Script Inputs

For the ArcGIS script execution, the following inputs are needed:

• Stream centerline (route [M] enabled)
• Optional regional curve information relating drainage area to a bankfull width
• Digitized valley walls (left/right)
• Flow accumulation layer (derived in previous hydrologic processing of the DEM)

This [cross-sections presentation] (CrossSectionsScript.pdf) is an overview of the script parameters and execution.

Motivation

Previously, these cross-sections had to be manually digitized by the user in GIS, which took a while when you had a large watershed. The script I wrote significantly reduces the time to create these cross-sections throughout a watershed. Other scripts have performed a similar task, but I need my cross-sections to be perpendicular to the stream channel wihtin the channel banks, and perpendicular to the valley walls once out of the banks.

Installation

Download the [ArcToolbox and script (.zip file)] (CrossSections.zip) to try in ArcGIS.

Tests

This script was developed and tested with ArcGIS 10.2, Python 2.7

Python modules needed: acrpy, math, sys, traceback

Contributors

Michael Harris is the author of this script.

[StackOverflow] (http://stackoverflow.com/users/4530995/michael-harris)

[LinkedIN] (https://www.linkedin.com/in/michael-harris-366b0060/)

Acknowledgements

Some code snippets and ideas were obtained from Mark Ellefson 'Classify Stream Type' script and 'Perpendicular Transects' script by Mateus Ferreira.

License

This code is available under the [MIT License.] (LICENSE.txt)