View In:   ArcGIS Online Map Viewer

Name: 2022 Impervious Surface

Display Field: NAME

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: This map was derived from a 12-class land-cover product developed for the Chesapeake Bay Watershed. It was extracted from a map showing land-cover conversion in the Chesapeake Bay Watershed during the period 2017/2018-2021/2022. The change-detection map was modeled with an existing 2017/2018 (Time Period 2, or T2) land-cover map containing the following classes: Water, Emergent Wetlands, Tree Canopy, Scrub\Shrub, Low Vegetation, Barren, Impervious Structures, Other Impervious, Impervious Roads, Tree Canopy Over Impervious Structures, Tree Canopy Over Other Impervious, and Tree Canopy Over Impervious Roads. Using object-based image analysis mapping techniques, the T2 map was first refined, where necessary, using all remote-sensing imagery and GIS datasets available for 2021\2022, including LiDAR, multispectral imagery, and thematic layers (e.g., roads, building footprints). The refined T2 map was then compared to imagery and GIS data corresponding to the period 2021/2022 (Time Period 3, or T3), identifying features that had changed during the analysis interval. Each change combination was assigned to a unique category that indicated both the "from" and "to" classes, enabling monitoring of specific types of change. Features that had not changed during the analysis interval were also incorporated into the change map, making it possible to reconstitute full land cover for either T2 or T3. Draft output was manually reviewed and edited to eliminate obvious errors of omission and commission, focusing on the most important types of landscape change: 1) tree-canopy loss; and 2) impervious-surfaces gain. The final map contained 79 change classes plus the original 12 classes for features that had not changed. The specific analysis periods for the watershed's 7 states\districts were: Delaware, 2018-2021; District of Columbia, 2017-2021; Maryland, 2018-2021; New York, 2017-2022; Pennsylvania, 2017-2022; Virginia, 2018-2021; and West Virginia, 2018-2022. The 12-class extract of the change-detection map was created by reassigning all change classes to their T3 status.For specific use in land-use\land-cover (LULC) analyses for Delaware, the T3 map produced for the Chesapeake Bay Watershed was reclassifed into two classes: Impervious (1); and Pervious (2). It was reviewed and edited against 2022 leaf-off imagery to update it to 2022 conditions. This map was based on a draft version of Chesapeake Bay Watershed land cover. A publicly-available version of the final Chesapeake Bay map will be available in autumn 2024, through the Chesapeake Conservancy (https://www.chesapeakeconservancy.org/).

Copyright Text: The University of Vermont Spatial Analysis Laboratory developed this map in cooperation with the Chesapeake Conservancy and the U.S. Geological Survey.

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 0.0

Max Scale: 0.0

Supports Advanced Queries: true

Supports Statistics: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports ValidateSQL: true

Supports Calculate: true

Supports Datum Transformation: true

Extent:

XMin: -8436794.96343885
YMin: 4643354.26642941
XMax: -8348919.9437
YMax: 4842649.26642942
Spatial Reference: 102100  (3857)  LatestVCSWkid(0)

Drawing Info:

Renderer:
Unique Value Renderer:
Field 1: CLASS
Field 2: N/A
Field 3: N/A
Field Delimiter: ,
Default Symbol:
N/A
Default Label: N/A
UniqueValueInfos:
• Value: Impervious
  Label: Impervious
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [104, 104, 104, 255]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 255]
  Width: 0
• Value: Pervious
  Label: Pervious
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [180, 252, 179, 0]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 0]
  Width: 0
Transparency: 0
Labeling Info:

Advanced Query Capabilities:

Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: true
Supports Returning Geometry Centroid: true
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false
Supports Percentile Statistics: true
Supports Having Clause: true
Supports Count Distinct: true
Supports Time Relation: false
Supports Sql Format: false
Supports Query Analytic: true
Supports Query With Current User: true

HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: CLASS

Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID, editable: false, nullable: false, defaultValue: null, modelName: OBJECTID )
• GRIDCODE ( type: esriFieldTypeInteger, alias: gridcode, editable: true, nullable: true, defaultValue: null, modelName: GRIDCODE )
• CLASS ( type: esriFieldTypeString, alias: Class, editable: true, nullable: true, length: 15, defaultValue: null, modelName: CLASS )
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• Shape__Length ( type: esriFieldTypeDouble, alias: SHAPE.LEN, editable: false, nullable: true, defaultValue: null, modelName: SHAPE.LEN, required: true )

Types:

ID: Impervious
Name: Impervious
Domains:
Templates:
• Name: Impervious
  Description:
  Prototype:
  NAME: null
  CLASS: Impervious
  GRIDCODE: null
  
  Drawing Tool: esriFeatureEditToolPolygon

---

ID: Pervious
Name: Pervious
Domains:
Templates:
• Name: Pervious
  Description:
  Prototype:
  NAME: null
  CLASS: Pervious
  GRIDCODE: null
  
  Drawing Tool: esriFeatureEditToolPolygon

---

Capabilities: Query

Sync Can Return Changes: false

Is Data Versioned: false

Supports Rollback On Failure: true

Supports ApplyEdits With Global Ids: false

Supports Query With Historic Moment: false

Supports Coordinates Quantization: true

Child Resources:   Field Groups   Contingent Values

Supported Operations:   Query   Query Analytic   Validate SQL   Generate Renderer   Return Updates   Iteminfo   Thumbnail   Metadata   Update Metadata