From Terrestrial Ecosystem Research Network
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Topographic Wetness Index derived from 1" SRTM DEM-H

Created 25/06/2025

Updated 25/06/2025

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Topographic Wetness Index (TWI) is calculated as log_e(specific catchment area / slope) and estimates the relative wetness within a catchment. The TWI product was derived from the partial contributing area product (CA_MFD_PARTIAL), which was computed from the Hydrologically enforced Digital Elevation Model (DEM-H; ANZCW0703014615), and from the percent slope product, which was computed from the Smoothed Digital Elevation Model (DEM-S; ANZCW0703014016). Both DEM-S and DEM-H are based on the 1 arcsecond resolution SRTM data acquired by NASA in February 2000. Note that the partial contributing area product does not always represent contributing areas larger than about 25 km2 because it was processed on overlapping tiles, not complete catchments. This only impacts TWI values in river channels and does not affect values on the land around the river channels. Since the index is not intended for use in river channels this limitation has no impact on the utility of TWI for spatial modelling. The TWI data are available in gridded format at 1 arcsecond and 3 arcsecond resolutions. The 3 arcsecond resolution TWI product was generated from the 1 arcsecond TWI product and masked by the 3” water and ocean mask datasets.

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Additional Info

Field Value
Title Topographic Wetness Index derived from 1" SRTM DEM-H
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/eeacd3e7-0170-4720-92e3-bfe86452e397
Contact Point
Terrestrial Ecosystem Research Network�s Data Discovery
esupport@tern.org.au
Reference Period 11/02/2000 - 22/02/2000
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        113.0,
        -44.0
      ],
      [
        154.0,
        -44.0
      ],
      [
        154.0,
        -10.0
      ],
      [
        113.0,
        -10.0
      ],
      [
        113.0,
        -44.0
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Terrestrial Ecosystem Research Network

Data Source

This dataset was originally found on Terrestrial Ecosystem Research Network "Topographic Wetness Index derived from 1" SRTM DEM-H". Please visit the source to access the original metadata of the dataset:
https://geonetwork.tern.org.au/geonetwork/srv/eng/csw/dataset/topographic-wetness-index-derived-from-1quot-srtm-dem-h