Name: Slope Gradient

Display Field: CDA_SlopeClass

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: This feature class has been derived from a 1-meter gridded topographic-bathymetric terrain model that was resampled from the MarinMap "tbsm45cm_201008" surface.Resampling was performed using ERDAS Imagine. The surface gradient, expressed as percentage slope, was calculated using ESRI ArcGIS Spatial Analyst functions.ESRI Spatial Analyst Surface functions were used to define contour line features at 15-percent, 26-percent, and 36-percent over the seamless 1-meter countywide slope grid.Considerable effort was expended to build these contours into polygon areas that identify the four slope classes that are discriminated by those three contours.The complexity and the extreme variation in length of the contours made it necessary to dice the segments with a 200-meter grid to shorten the boundaries around the resulting polygons.Once a clean polygon build was successful countywide, centroid points were generated for each polygon and used to interpolate the percent slope grid under each point.These points were then reclassified into the CDA-defined categories, and a coded-value domain was defined for the classification as follows:0 - slope less than 15 percent1 - slope from 15--25 percent2 - slope from 26--35 percent3 - slope 36 percent and greaterThe label points with coded-value attributes were used with the clean bounding lines to generate the final set of countywide slope contours.The development work was performed in US National Grid (WGS 1984 UTM zone 10 north meters) and exported to an ESRI Feature Dataset to project this version to MarinMap customary system (NAD 1983 HARN California Coordinates zone 3 US Survey feet)

Copyright Text: County of Marin, Community Development Agency, GIS Division Brian B. Quinn Ph.D. GISP bquinn@marincounty.org

Default Visibility: false

MaxRecordCount: 1000

Supported Query Formats: JSON, geoJSON

Min Scale: 2000

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: 5806509.861457884
YMin: 2113752.5620504767
XMax: 6030678.470946655
YMax: 2332205.105485916
Spatial Reference: 2872  (2872)

Drawing Info:

Renderer:
Unique Value Renderer:
Field 1: CDA_SlopeClass
Field 2: null
Field 3: null
Field Delimiter: ,
Default Symbol:
N/A
Default Label: null
UniqueValueInfos:
• Value: 3
  Label: slope 36 percent and greater
  Description:
  Symbol:
  Style: esriSFSSolid
  Color: [52, 52, 52, 191]
  Outline:
  Style: esriSLSNull
  Color: [0, 0, 0, 0]
  Width: 0
• Value: 2
  Label: slope from 26--35 percent
  Description:
  Symbol:
  Style: esriSFSSolid
  Color: [104, 104, 104, 191]
  Outline:
  Style: esriSLSNull
  Color: [0, 0, 0, 0]
  Width: 0
• Value: 1
  Label: slope from 15--25 percent
  Description:
  Symbol:
  Style: esriSFSSolid
  Color: [156, 156, 156, 191]
  Outline:
  Style: esriSLSNull
  Color: [0, 0, 0, 0]
  Width: 0
• Value: 0
  Label: slope less than 15 percent
  Description:
  Symbol:
  Style: esriSFSSolid
  Color: [0, 0, 0, 0]
  Outline:
  Style: esriSLSNull
  Color: [0, 0, 0, 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: false
Supports Returning Geometry Centroid: false

HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:

• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• CDA_SlopeClass ( type: esriFieldTypeSmallInteger, alias: CDA_slope_class , Coded Values: [0: slope less than 15 percent] , [1: slope from 15-25 percent] , [2: slope from 26-35 percent] , ...1 more... )
• SHAPE ( type: esriFieldTypeGeometry, alias: SHAPE )
• SHAPE.STArea() ( type: esriFieldTypeDouble, alias: SHAPE.STArea() )
• SHAPE.STLength() ( type: esriFieldTypeDouble, alias: SHAPE.STLength() )

Supported Operations:   Query   Query Attachments   Generate Renderer   Return Updates

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