Terrestrial Condition Assessment (TCA) Recent Drought Impacts (Image Service)

<div style='text-align:Left;'><div><div><p style='font-weight:bold;'><a href='https://data.fs.usda.gov/geodata/rastergateway/TCA/TCA_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 current moisture deficit and surplus relative to the long-term average.</span></span></p><p><span style='font-weight:bold;'><span>Data:</span></span><span><span> </span></span><span><span>The indicator represents areas of moisture deficit as a z-score. A z-score is a statistical method for assessing how different a value (i.e., most recent 3 years) is from the mean (historical average). The source climate data is from PRISM. Mean moisture values were derived from historical data on precipitation and Thornthwaite potential evapotranspiration, from 1900 to </span></span><span style='font-style:italic;'><span>t</span></span><span><span>-minus 4 (</span></span><span style='font-style:italic;'><span>t</span></span><span><span> = current TCA Assessment year). The greater the negative z-value, the larger the departure from average conditions, indicating larger moisture deficits.</span></span></p><p><span><span>These data highlight regions of moisture deficit as a z-score calculated from the reference time period and current conditions. There is a lag between the assessment year and the most recent drought data, for example, the 2024 TCA Assessment used 2021-2023 to represent current conditions and 1900-2020 for the reference time period. 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>Mean difference in z-score</span></span></p><p><span style='font-weight:bold;'><span>Spatial Resolution:</span></span><span><span> 4000m (4km)</span></span></p><p><span style='font-weight:bold;'><span>Source data:</span></span><span><span> </span></span><a href='http://www.prism.oregonstate.edu/' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>PRISM</span></span></a><span><span>; </span></span><span><span>z-score calculations provided by the USFS Office of Sustainability and Climate based on the methods found here: </span></span><a href='https://www.fs.usda.gov/research/treesearch/43361' style='text-decoration:underline;'><span style='text-decoration:underline;'><span>https://www.fs.usda.gov/research/treesearch/43361</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&amp;list=PLwRbAc4x5n94rLca1CXXuugtRDt_G666M&amp;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>