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Terrestrial Condition Assessment (TCA) Alaska Drought (Map Service)
Direct Download (Raster Data Gateway)Objective: Characterize recent drought severity in Alaska. Data: The indicator represents drought severity as a weighted sum of the number of droughts in each category over the most recent 3-year period using data from the U.S. Drought Monitor. A 30km grid was overlaid on Alaska and the number of droughts in each category we calculated over the time period. The weighted sum of droughts (DwSum) was calculated using the equation: (D0 [abnormally dry] * 1) + (D1 [moderate drought] *2) + (D2 [severe drought] * 3) + (D3 [extreme drought] * 4) + (D4 [exceptional drought] * 5)There is a lag between the assessment year and the most recent drought data, for example, the 2024 TCA Assessment used drought data from 2021-2023. Data were summarized at the Subsection scale of the USFS National Hierarchy of Ecological Units and applied to the corresponding landscape (LTA).Data Format: Raster data are continuousUnits: Number of droughts (weighted sum)Spatial Resolution: 30000m (30km)Source data: US Drought MonitorAdditional Resources:Details on Method Changes and Source Data VersionsOverview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour PresentationExplore the results of the most recent assessment: TCA Interactive Data ViewerLearn more about the TCA KPI: TCA Dashboard*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request
Resources
3 resources available
-
ArcGIS Hub Dataset
WEB PAGE -
ArcGIS GeoService
ARCGIS GEOSERVICES REST API -
ISO-19139 metadata
TEXT/XML
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[
"005:96"
]
|
| contactPoint |
{
"fn": "USFSEnterpriseContent",
"@type": "vcard:Contact",
"hasEmail": "mailto:SM.FS.data@usda.gov"
}
|
| description | <div style='text-align:Left;'><div><div><p style='font-weight:bold;'><a href='https://data.fs.usda.gov/geodata/rastergateway/TCA/Alaska/04_Climate/TCA_AK_Drought_Impacts.zip' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>Direct Download (Raster Data Gateway)</span></span></a></p><p><span style='font-weight:bold;'><span>Objective:</span></span><span><span> Characterize recent drought severity in Alaska. </span></span></p><p><span style='font-weight:bold;'><span>Data:</span></span><span><span> </span></span><span><span>The indicator represents drought severity as a weighted sum of the number of droughts in each category over the most recent 3-year period using data from the U.S. Drought Monitor. A 30km grid was overlaid on Alaska and the number of droughts in each category we calculated over the time period. The weighted sum of droughts (</span></span><span style='font-style:italic;'><span>DwSum</span></span><span><span>) was calculated using the equation:</span></span></p><p style='font-style:italic;'><span> </span><span><span>(D0 [abnormally dry] * 1) + (D1 [moderate drought] *2) + (D2 [severe drought] * 3) + (D3 [extreme drought] * 4) + (D4 [exceptional drought] * 5)</span></span></p><p><span><span>There is a lag between the assessment year and the most recent drought data, for example, the 2024 TCA Assessment used drought data from 2021-2023. Data were summarized at the Subsection scale of the USFS National Hierarchy of Ecological Units and applied to the corresponding landscape (LTA).</span></span></p><p><span style='font-weight:bold;'><span>Data Format:</span></span><span><span> Raster data are continuous</span></span></p><p><span style='font-weight:bold;'><span>Units: </span></span><span><span>Number of droughts (weighted sum)</span></span></p><p><span style='font-weight:bold;'><span>Spatial Resolution:</span></span><span><span> 30000m (30km)</span></span></p><p><span style='font-weight:bold;'><span>Source data:</span></span><span><span> </span></span><a href='https://droughtmonitor.unl.edu/CurrentMap.aspx' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>US Drought Monitor</span></span></a></p><p style='font-weight:bold;'><span><span>Additional Resources:</span></span></p><p><span><span>Details on </span></span><a href='https://usfs.box.com/s/79vx1b42xg8u6ivjombxjes36nzfhgml' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>Method Changes and Source Data Versions</span></span></a></p><p><span><span>Overview of the Terrestrial Condition Assessment: </span></span><a href='https://terrestrial-condition-assessment-usfs.hub.arcgis.com/' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>TCA Hubsite</span></span></a><span><span> or </span></span><a href='https://www.youtube.com/watch?v=Kf0P3cAq1rs&list=PLwRbAc4x5n94rLca1CXXuugtRDt_G666M&index=19' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>Landfire Office Hour Presentation</span></span></a></p><p><span><span>Explore the results of the most recent assessment: </span></span><a href='https://apps.fs.usda.gov/gtac-toolsms/tca/' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>TCA Interactive Data Viewer</span></span></a></p><p><span><span>Learn more about the TCA KPI: </span></span><a href='https://cxodashboard.dl.usda.gov/t/NRE/views/EcologicalConditionOutcomes_17531128629260/EcologicalOutcomes' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>TCA Dashboard</span></span></a></p><p><span><span>*if you have trouble viewing the Dashboard, please submit a </span></span><a href='https://usdagcc.sharepoint.com/sites/fs-wo-cdoc/SitePages/Dashboards.aspx' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>Tableau Viewer Access Request</span></span></a></p></div></div></div> |
| distribution |
[
{
"@type": "dcat:Distribution",
"title": "ArcGIS Hub Dataset",
"format": "Web Page",
"accessURL": "https://data-usfs.hub.arcgis.com/datasets/usfs::terrestrial-condition-assessment-tca-alaska-drought-map-service-1",
"mediaType": "text/html"
},
{
"@type": "dcat:Distribution",
"title": "ArcGIS GeoService",
"format": "ArcGIS GeoServices REST API",
"accessURL": "https://imagery.geoplatform.gov/iipp/rest/services/Ecosystems/USFS_EDW_TCA_AK_Drought/ImageServer",
"mediaType": "application/json"
},
{
"@type": "dcat:Distribution",
"title": "ISO-19139 metadata",
"accessURL": "https://www.arcgis.com/sharing/rest/content/items/e6a778ddd3294f08bbc91d99e56d0a60/info/metadata/metadata.xml?format=iso19139",
"mediaType": "text/xml",
"conformsTo": "https://www.isotc211.org/2005/gmi"
}
]
|
| identifier | https://www.arcgis.com/home/item.html?id=e6a778ddd3294f08bbc91d99e56d0a60 |
| issued | 2025-09-18 |
| keyword |
[
"AK",
"Alaska",
"Climate",
"Drought",
"Geospatial Office",
"PRISM",
"TCA",
"Terrestrial Condition Assessment",
"USFS"
]
|
| landingPage | https://data-usfs.hub.arcgis.com/datasets/usfs::terrestrial-condition-assessment-tca-alaska-drought-map-service-1 |
| license | https://creativecommons.org/licenses/by/4.0/ |
| modified | 2025-09-23 |
| programCode |
[
"005:059"
]
|
| progressCode | onGoing |
| publisher |
{
"name": "U.S. Forest Service",
"source": "USDA Forest Service"
}
|
| spatial | -179.8824,49.6078,-121.0871,71.8283 |
| theme |
[
"geospatial"
]
|
| title | Terrestrial Condition Assessment (TCA) Alaska Drought (Map Service) |
