Topographic Wetness Index raster - Land Cover Mapping, North Slope of the Arctic National Wildlife Refuge, Alaska, 2019

"We obtained the 5 m Interferometric Synthetic Aperture Radar Digital Terrain Model (IFSAR DTM) tiles for the study area from https://elevation.alaska.gov/ and mosaicked the products into a single image. We aggregated the DTM to 30 m resolution to represent a more generalized landscape level, and also to allow fairly rapid calculation of more processing-intensive terrain metrics. We then calculated the Sage Topographic Wetness Index at 30 m resolution. This integrates the local slope and the upstream contributing terrain in a continuous metric representing the potential wetness.

The 'SAGA Wetness Index' is, as the name says, similar to the 'Topographic Wetness Index' (TWI), but it is based on a modified catchment area calculation ('Modified Catchment Area'), which does not think of the flow as very thin film. As result it predicts for cells situated in valley floors with a small vertical distance to a channel a more realistic, higher potential soil moisture compared to the standard TWI calculation."

Data and Resources

Field Value
accessLevel public
bureauCode {010:18}
catalog_@context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
dataQuality true
identifier FWS_ServCat_130646
issued 2020-06-01
landingPage https://ecos.fws.gov/ServCat/Reference/Profile/130646
modified 2020-06-01
old-spatial -149.387222,66.7421341,-141.000626,70.1697845
programCode {010:094,010:028}
publisher Fish and Wildlife Service
references {https://ecos.fws.gov/ServCat/Reference/Profile/130646}
resource-type Dataset
source_datajson_identifier true
source_hash 28cd4221ef7d6084bf5a8325c826fef02b6f2775
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-149.387222, 66.7421341], [-149.387222, 70.1697845], [-141.000626, 70.1697845], [-141.000626, 66.7421341], [-149.387222, 66.7421341]]]}
temporal 2018-10-01/2019-07-01
theme {"Geospatial Dataset"}
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • anwr
  • arctic-coastal-plain
  • ckan
  • classification
  • ecological-land-survey
  • geo
  • geoss
  • habitat
  • land-cover
  • mapping
  • national
  • north-america
  • north-slope
  • remote-sensing
  • soil-analysis
  • united-states
  • vegetation
isopen False
license_id notspecified
license_title License not specified
maintainer Todd Sutherland
maintainer_email todd_sutherland@fws.gov
metadata_created 2025-11-21T23:01:27.125177
metadata_modified 2025-11-21T23:01:27.125181
notes "We obtained the 5 m Interferometric Synthetic Aperture Radar Digital Terrain Model (IFSAR DTM) tiles for the study area from https://elevation.alaska.gov/ and mosaicked the products into a single image. We aggregated the DTM to 30 m resolution to represent a more generalized landscape level, and also to allow fairly rapid calculation of more processing-intensive terrain metrics. We then calculated the Sage Topographic Wetness Index at 30 m resolution. This integrates the local slope and the upstream contributing terrain in a continuous metric representing the potential wetness. The 'SAGA Wetness Index' is, as the name says, similar to the 'Topographic Wetness Index' (TWI), but it is based on a modified catchment area calculation ('Modified Catchment Area'), which does not think of the flow as very thin film. As result it predicts for cells situated in valley floors with a small vertical distance to a channel a more realistic, higher potential soil moisture compared to the standard TWI calculation."
num_resources 1
num_tags 19
title Topographic Wetness Index raster - Land Cover Mapping, North Slope of the Arctic National Wildlife Refuge, Alaska, 2019