Name: Erosion and sediment risk - catchment scale

Display Field: HydroCat

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: This vector dataset represents a polygonised summary of terrain, hydrological, and regolith susceptibility inputs across DRN watersheds (at 2ha drainage thresholds). It contains zonal statistics derived from continuous raster and classed surfaces, which were used to evaluate spatial variation in erosion susceptibility at sub-catchment scale (DRN 2ha watersheds).Key attributes include majority values from input rasters to S-PAL model (Sediment Process Attribute Layer) such as overland flow or “Sediment runoff risk”, regolith activity or “Geological risk”, hydrological susceptibility or “Soil permeability”, as well as slope and elevation, S-PAL siblings.The symbology (erosion risk classes) of this layer is based on the attribute field “Erosion risk” which is informed by combination of two factors - “Geological risk” and “Sediment runoff risk” at 50:50 ratio.For details see the Land & Water Science report (Gunn and Rissmann 2025) - Northland Erosion and Sediment Risk Map - Metadata Report LWS 2026.pdfAttribute field | Field descriptionsMultiple fields, see below:Erosion Risk: 1-5 categories (where 1 = low risk, and 5 = high risk) from composite of two factors - inherent “Geological risk” and “Sediment runoff risk” at 50:50 ratioGeological RiskA70_O30_Quantile_Majority to A30_O70_Quantiles_Majority: Majority susceptibility class (1-5) from combined susceptibility layers (at various proportions of regolith and OLF susceptibility e.g. 70% regolith and 30% OLF), where 1 = low susceptibility, 2 = moderately low susceptibility, 3 = moderate susceptibility, 4 = moderately high susceptibility, and 5 = high susceptibility.Sibling_Class_Majority: Majority class from SPAL_4_12_35 rasterAuthor: Dr Clint Rissmann (Land & Water Science)Extent: Whole NorthlandProjection: NZTM (EPSG:2193)Coarsest Scale of Component Dataset: 1:63,000 soil derived informationVersion: Version 2.0Date Created: July 2025Date Modified: May 2026NRC Team (if applicable): Natural Resources Science TeamSubject Matter Expert: Clint Rissmann – Landscape ScientistFile Size: 4.35 GBData Provided by: Manas Chakraborty (Resource Scientist - Freshwater)

Service Item Id: 6d86e27a506849e09ded0b952e67faff

Copyright Text: Land & Water Science; NRC

Default Visibility: true

MaxRecordCount: 2000

MaxSelectionCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 2.0E7

Max Scale: 10000.0

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: 1567223.0
YMin: 5971870.0
XMax: 1745598.0
YMax: 6194217.0
Spatial Reference: 2193  (2193)  LatestVCSWkid(0)

Drawing Info:

Renderer:
Unique Value Renderer:
Field 1: A50_O50_Quantile_Majority
Field 2: N/A
Field 3: N/A
Field Delimiter: ,
Default Symbol:
N/A
Default Label: N/A
UniqueValueInfos:
• Value: 1
  Label: 1 = Low
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [115, 255, 223, 255]
  Outline:
  Style: esriSLSNull
  Color: [110, 110, 110, 255]
  Width: 0
• Value: 2
  Label: 2 = Moderately low
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [56, 168, 0, 255]
  Outline:
  Style: esriSLSNull
  Color: [110, 110, 110, 255]
  Width: 0
• Value: 3
  Label: 3 = Moderate
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [85, 255, 0, 255]
  Outline:
  Style: esriSLSNull
  Color: [110, 110, 110, 255]
  Width: 0
• Value: 4
  Label: 4 = Moderately high
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [255, 255, 0, 255]
  Outline:
  Style: esriSLSNull
  Color: [110, 110, 110, 255]
  Width: 0
• Value: 5
  Label: 5 = High
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [255, 170, 0, 255]
  Outline:
  Style: esriSLSNull
  Color: [110, 110, 110, 255]
  Width: 0
Transparency: 40
Labeling Info:

Feature Draw Order:

N/A

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: false
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, length: 8 )
• A50_O50_Quantile_Majority ( type: esriFieldTypeDouble, alias: Erosion risk )
• Regolith_Activity_Class_Majority ( type: esriFieldTypeDouble, alias: Geological risk (1=low, 5=high) )
• OLF_Classes_Majority ( type: esriFieldTypeDouble, alias: Sediment runoff risk (1=low, 5=high) )
• Slope_Index_Mean ( type: esriFieldTypeDouble, alias: Slope index (0=flat, 1=very steep) )
• HYD_Index_Mean ( type: esriFieldTypeDouble, alias: Soil permeability (0=very good, 1=very bad) )
• Slope_degree ( type: esriFieldTypeDouble, alias: Slope (degree) )
• FMU_1 ( type: esriFieldTypeString, alias: Parent catchment, length: 255 )
• HydroCat ( type: esriFieldTypeString, alias: Sub-catchment, length: 254 )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• WatershedID ( type: esriFieldTypeInteger, alias: WatershedID )
• HydroID ( type: esriFieldTypeInteger, alias: HydroID )
• Slope_Mean ( type: esriFieldTypeDouble, alias: Slope_Mean )
• Slope_Max ( type: esriFieldTypeDouble, alias: Slope_Max )
• Elevation_Mean ( type: esriFieldTypeDouble, alias: Elevation_Mean )
• Elevation_Max ( type: esriFieldTypeDouble, alias: Elevation_Max )
• Rec2_SegmentID ( type: esriFieldTypeInteger, alias: Rec2_SegmentID )
• Rec2_ReachID ( type: esriFieldTypeInteger, alias: Rec2_ReachID )
• Upstream_Slope_Mean ( type: esriFieldTypeDouble, alias: Upstream_Slope_Mean )
• Upstream_Elevation_Mean ( type: esriFieldTypeDouble, alias: Upstream_Elevation_Mean )
• Upstream_Area ( type: esriFieldTypeDouble, alias: Upstream_Area )
• SPAL_Domain_6_Majority ( type: esriFieldTypeDouble, alias: SPAL_Domain_6_Majority )
• SPAL_Family_12_Majority ( type: esriFieldTypeDouble, alias: SPAL_Family_12_Majority )
• SPAL_Sibling_35_Majority ( type: esriFieldTypeDouble, alias: SPAL_Sibling_35_Majority )
• Shape_Length ( type: esriFieldTypeDouble, alias: Shape_Length )
• Shape_Area ( type: esriFieldTypeDouble, alias: Shape_Area )

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

  Iteminfo   Thumbnail   Metadata