View In:   ArcGIS Online Map Viewer

Name: Tree Canopy

Display Field: CLASS

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: This layer is a high-resolution tree canopy change-detection layer for Prince George's and Montgomery Counties, Maryland. It contains three tree-canopy classes for the period 2014-2018: (1) No Change; (2) Gain; and (3) Loss. It was created by mapping the change from the source LiDAR and imagery for the two time periods. Tree canopy that existed during both time periods was assigned to the No Change category while trees removed, felled in storms, or canopy to disease were assigned to the Loss class. New tree canopy, either the result of natural growth or new plantings was assigned to the Gain class . Change was mapped using object-based image analysis (OBIA) techniques and included similar source datasets (LiDAR-derived surface models, multispectral imagery, and thematic GIS inputs) for the two time periods. OBIA systems work by grouping pixels into meaningful objects based on their spectral and spatial properties, while taking into account boundaries imposed by existing vector datasets. Within the OBIA environment, a rule-based expert system was designed to effectively mimic the process of manual image analysis by incorporating the elements of image interpretation (color/tone, texture, pattern, location, size, and shape) into the classification process. A series of morphological procedures were employed to ensure that the end product is both accurate and cartographically pleasing. No accuracy assessment was conducted, but the dataset was subjected to a detailed manual review and correction. No minimum mapping unit was enforced. All detectable tree canopy was retained in the dataset.

Service Item Id: 5a2477a63c2f4ea589b05985f5f70f31

Copyright Text: The University of Vermont Spatial Analysis Laboratory created this datasets in collaboration with Sanborn.

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 0

Max Scale: 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: 1162675.99975121
YMin: 461880.999889776
XMax: 1343910.4682214
YMax: 614381.219396681
Spatial Reference: 102685  (2248)

Drawing Info:

Renderer:
Simple Renderer:
Symbol:
Style: esriSFSSolid
Color: [115, 178, 115, 255]
Outline:
N/A
Label: N/A
Description: N/A
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:

Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID, editable: false, nullable: false, defaultValue: null, modelName: OBJECTID )
• CLASS ( type: esriFieldTypeString, alias: Tree Canopy Change Class, editable: true, nullable: true, length: 255, defaultValue: null, modelName: Class_Text )
• Shape__Area ( type: esriFieldTypeDouble, alias: SHAPE.AREA, editable: false, nullable: true, defaultValue: null, modelName: SHAPE.AREA, required: true )
• Shape__Length ( type: esriFieldTypeDouble, alias: SHAPE.LEN, editable: false, nullable: true, defaultValue: null, modelName: SHAPE.LEN, required: true )

Templates:

• Name: Tree Canopy
  Description:
  Prototype:
  CLASS: null
  
  Drawing Tool: esriFeatureEditToolPolygon

Capabilities: Query,Create,Update,Delete,Uploads,Editing

Sync Can Return Changes: false

Is Data Versioned: true

Supports Rollback On Failure: false

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   Apply Edits   Add Features   Update Features   Delete Features   Calculate   Validate SQL   Generate Renderer   Return Updates   Iteminfo   Thumbnail   Metadata   Update Metadata