Notice: For ArcGIS users, portions of this tool have been rewritten and are available in the ArcGIS Land Facet Corridor Designer extension.
NAME: Topographic Position Index (TPI) v. 1.3a (Click name to download)
View and Download TPI Poster
Last modified: September 15, 2006
TOPICS: Topography Position Index TPI Landform Slope Classification Standardization Neighborhood Statistics
AUTHOR: Jeff Jenness, GIS Analyst
DESCRIPTION: This extension
calculates Topographic Position Index (TPI) grids from elevation grids, and
provides a simple and repeatable method to classify the landscape into slope
position and landform category using the TPI values.
author gratefully acknowledges the work of Andrew Weiss who originally
developed the TPI methodology and concepts. This extension automates Weiss’
methods and allows users to save and share classification criteria sets.
REQUIRES: Spatial Analyst
This extension also requires that the file "avdlog.dll" be present in the ArcView/BIN32 directory (or $AVBIN/avdlog.dll) and that the Dialog Designer extension be located in your ArcView/ext32 directory, which they usually are if you're running AV 3.1 or better. The Dialog Designer doesn't have to be loaded; it just has to be available. If you are running AV 3.0a, you can download the appropriate files for free from ESRI at:
Recommended Citation Format: For those who wish to cite this extension, the author recommends something similar to:
Jenness, J. 2006. Topographic Position Index (tpi_jen.avx) extension for ArcView 3.x, v. 1.3a. Jenness Enterprises. Available at: http://www.jennessent.com/arcview/tpi.htm.
Please let me know if you cite this extension in a publication (firstname.lastname@example.org). I will update the citation list to include any publications that I am told about.
Enjoy! Please contact the author if you have problems or find bugs.
Jeff Jenness email@example.com
Jenness Enterprises http://www.jennessent.com
3020 N. Schevene Blvd.
Flagstaff, AZ 86004
Please visit Jenness Enterprises ArcView Extensions site for more ArcView Extensions and other software by the author. We also offer customized ArcView-based GIS consultation services to help you meet your specific data analysis and application development needs.