{ "extent": { "ymin": 2262629.9694999978, "xmin": -15130348.178399999, "ymax": 6982629.9694999978, "xmax": -6174348.1783999987, "spatialReference": { "latestWkid": 3857, "wkid": 102100 } }, "blockWidth": 2048, "mosaicOperator": "First", "serviceSourceType": "esriImageServiceSourceTypeMosaicDataset", "hasMultidimensions": true, "maxImageWidth": 100000, "maxRecordCount": 1000, "meanValues": [1.0253613377932191], "hasColormap": false, "compressionType": "None", "defaultCompressionQuality": 75, "maxValues": [5.3067703247070312], "hasHistograms": true, "datasetFormat": "AMD", "maxImageHeight": 100000, "sortField": "StdTime", "bandNames": ["Band_1"], "spatialReference": { "latestWkid": 3857, "wkid": 102100 }, "fullExtent": { "ymin": 2262629.9694999978, "xmin": -15130348.178399999, "ymax": 6982629.9694999978, "xmax": -6174348.1783999987, "spatialReference": { "latestWkid": 3857, "wkid": 102100 } }, "bandCount": 1, "rasterFunctionInfos": [ { "help": "", "name": "None", "description": "Make a Raster or Raster Dataset into a Function Raster Dataset." }, { "help": "", "name": "Drought", "description": "A raster function template." } ], "supportsStatistics": true, "sortableFields": "minps,maxps,lowps,highps,centerx,centery,zorder,Year,StdTime", "minValues": [-3.9039897918701172], "allowRasterFunction": true, "allowComputeTiePoints": false, "serviceDataType": "esriImageServiceDataTypeScientific", "supportsAdvancedQueries": true, "maxDownloadSizeLimit": 2048, "currentVersion": 11.5, "sortValue": "0", "timeInfo": { "startTimeField": "StdTime", "endTimeField": "StdTime", "defaultTimeIntervalUnits": "esriTimeUnitsYears", "timeExtent": [ 1577836800000, 1704067200000 ], "timeReference": null, "defaultTimeInterval": 1 }, "objectIdField": "objectid", "blockHeight": 256, "initialExtent": { "ymin": 2262629.9694999978, "xmin": -15130348.178399999, "ymax": 6982629.9694999978, "xmax": -6174348.1783999987, "spatialReference": { "latestWkid": 3857, "wkid": 102100 } }, "pixelSizeX": 4000, "pixelSizeY": 4000, "defaultMosaicMethod": "ByAttribute", "name": "Ecosystems/USFS_EDW_TCA_Drought", "allowedMosaicMethods": "ByAttribute,NorthWest,Center,LockRaster,Nadir,Viewpoint,Seamline,None", "maxDownloadImageCount": 20, "fields": [ { "domain": null, "name": "objectid", "alias": "objectid", "type": "esriFieldTypeOID" }, { "domain": null, "name": "name", "length": 200, "alias": "name", "type": "esriFieldTypeString" }, { "domain": null, "name": "minps", "alias": "minps", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "maxps", "alias": "maxps", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "lowps", "alias": "lowps", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "highps", "alias": "highps", "type": "esriFieldTypeDouble" }, { "domain": { "splitPolicy": "esriSPTDefaultValue", "name": "MosaicCatalogItemCategoryDomain", "description": "Catalog item categories.", "type": "codedValue", "codedValues": [ { "code": 0, "name": "Unknown" }, { "code": 1, "name": "Primary" }, { "code": 2, "name": "Overview" }, { "code": 3, "name": "Unprocessed Overview" }, { "code": 4, "name": "Partial Overview" }, { "code": 5, "name": "Inactive" }, { "code": 253, "name": "Uploaded" }, { "code": 254, "name": "Incomplete" }, { "code": 255, "name": "Custom" } ], "mergePolicy": "esriMPTDefaultValue" }, "name": "category", "alias": "category", "type": "esriFieldTypeInteger" }, { "domain": null, "name": "tag", "length": 100, "alias": "tag", "type": "esriFieldTypeString" }, { "domain": null, "name": "groupname", "length": 100, "alias": "groupname", "type": "esriFieldTypeString" }, { "domain": null, "name": "productname", "length": 100, "alias": "productname", "type": "esriFieldTypeString" }, { "domain": null, "name": "centerx", "alias": "centerx", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "centery", "alias": "centery", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "zorder", "alias": "zorder", "type": "esriFieldTypeInteger" }, { "domain": null, "name": "shape", "alias": "shape", "type": "esriFieldTypeGeometry" }, { "domain": null, "name": "condition", "length": 24, "alias": "condition", "type": "esriFieldTypeString" }, { "domain": null, "name": "year", "length": 8, "alias": "year", "type": "esriFieldTypeDate" }, { "domain": null, "name": "stdtime", "length": 8, "alias": "Standard Time", "type": "esriFieldTypeDate" }, { "domain": null, "name": "dimensions", "length": 50, "alias": "Dimensions", "type": "esriFieldTypeString" }, { "domain": null, "name": "variable", "length": 50, "alias": "Variable", "type": "esriFieldTypeString" }, { "domain": null, "name": "st_area(shape)", "alias": "st_area(shape)", "type": "esriFieldTypeDouble" }, { "domain": null, "name": "st_perimeter(shape)", "alias": "st_perimeter(shape)", "type": "esriFieldTypeDouble" } ], "defaultVariable": "", "allowAnalysis": true, "hasRasterAttributeTable": false, "useStandardizedQueries": true, "description": "", "pixelType": "F32", "meanPixelSize": 4000, "exportTilesAllowed": false, "editFieldsInfo": null, "rasterTypeInfos": [{ "help": "", "name": "Raster Dataset", "description": "Supports all ArcGIS Raster Datasets" }], "defaultResamplingMethod": "Bilinear", "itemAccess": false, "minScale": 0, "serviceProperties": "ByAttribute<\/MosaicMethod>First<\/MosaicOperator>false<\/SortAscending><\/LockImageID>StdTime<\/TileOrderField>0<\/TileOrderBase>600.000000<\/AvgImageSpacingX>300.000000<\/AvgImageSpacingY>0.0<\/ViewPointX>0.0<\/ViewPointY>0.0<\/ViewPointDefShiftX>0.0<\/ViewPointDefShiftY>None<\/CompressionMethod>75<\/CompressionQuality>0.010000<\/CompressionTolerance>Bilinear<\/SamplingMethod><\/ImageServiceProperties><\/ImageServer>", "advancedQueryCapabilities": { "supportsStatistics": true, "supportsOrderBy": true, "useStandardizedQueries": true, "supportsPagination": true, "supportsDistinct": true }, "serviceItemId": "24b6d829461d44f2acdd1a71ded16bcf", "capabilities": "Image,Metadata,Catalog,Mensuration", "maxScale": 0, "stdvValues": [1.3080319133456524], "allowedFields": "name,minps,maxps,lowps,highps,tag,groupname,productname,centerx,centery,zorder,st_area(shape),st_perimeter(shape),Condition,Year,StdTime,Dimensions,Variable", "minPixelSize": 0, "sortAscending": false, "maxMosaicImageCount": 20, "inspectionCapabilities": "", "maxPixelSize": 0, "uncompressedSize": 10568080, "serviceDescription": "

Direct Download (Raster Data Gateway)

Objective: Characterize current moisture deficit and surplus relative to the long-term average.

Data: 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 t-minus 4 (t = current TCA Assessment year). The greater the negative z-value, the larger the departure from average conditions, indicating larger moisture deficits.

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).

Data Format: Raster data are continuous

Units: Mean difference in z-score

Spatial Resolution: 4000m (4km)

Source data: PRISM; z-score calculations provided by the USFS Office of Sustainability and Climate based on the methods found here: https://www.fs.usda.gov/research/treesearch/43361

Additional Resources:

Details on Method Changes and Source Data Versions

Overview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour Presentation

Explore the results of the most recent assessment: TCA Interactive Data Viewer

Learn more about the TCA KPI: TCA Dashboard

*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request", "allowCopy": true, "copyrightText": "USDA - GEO; USDA - USFS \u2013 GO", "mensurationCapabilities": "Basic", "ownershipBasedAccessControlForRasters": null }