authority: folia
slug: tpi
name: Topographic Position Index
domain: land
subdomain: topography
authority_id: folia:tpi
parent: elevation
aliases:
  - topographic-position-index
external_ids:
  cf_standard_name: null
canonical_units: m
external_validations:
  gdal:
    tool: gdaldem
    algorithm: TPI
    docs_url: https://gdal.org/programs/gdaldem.html#topographic-position-index-tpi
  library:
    name: whitebox-tools
    id: RelativeTopographicPosition
    docs_url: https://www.whiteboxgeo.com/manual/wbt_book/available_tools/geomorphometric_analysis.html#RelativeTopographicPosition
description: |
  Difference between a pixel's elevation and the mean elevation of its
  neighbourhood. Positive values indicate ridges and crests, negative
  values indicate valleys and depressions, near-zero values indicate
  flat areas or constant slopes. Window size is configurable;
  larger windows surface broader landforms. Used to classify
  landforms and segment habitat zones.
theme: terrain
consumed_by: []
produced_by:
  - terrain_tpi
demos: []
status: documented
sources:
  - https://gdal.org/programs/gdaldem.html#topographic-position-index-tpi
  - Weiss, A.D. 2001, Topographic Position and Landforms Analysis, ESRI User Conference Poster