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: c85332ee76d342e293a46e4f3f322412

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

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: 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: false
Supports Returning Geometry Centroid: false
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: true
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: null

Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• CLASS ( type: esriFieldTypeString, alias: Tree Canopy Change Class, length: 255 )
• SHAPE ( type: esriFieldTypeGeometry, alias: SHAPE )
• SHAPE.AREA ( type: esriFieldTypeDouble, alias: SHAPE.AREA )
• SHAPE.LEN ( type: esriFieldTypeDouble, alias: SHAPE.LEN )

Supported Operations:   Query   Query Attachments   Query Analytic   Generate Renderer   Return Updates

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