Erosion_and_sediment_risk_map

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Service Description: <div style='text-align:Left;'><div><div>This vector dataset represents a polygonised summary of terrain, hydrological, and regolith susceptibility inputs over 2 ha DRN watersheds. It contains zonal statistics derived from continuous rasters and classed surfaces, used to evaluate spatial variation in erosion susceptibility at the subcatchment scale.Key attributes include majority values from classed S-PAL rasters (e.g. overland flow or OLF quantiles denoted by O, regolith activity quantiles denoted by A, S-PAL sibling classes), as well as upstream means of slope and elevation, and hydrological susceptibility indices (HYD and slope index).The symbology (erosion risk classes) of this vector layer is based on composite of two S-PAL factors - regolith activity (A) and overland flow (OLF) susceptibility at 50:50 ratio indicated by the attribute field ‘A50_O50_Quantile_Majority’.For details see the Land & Water Science report (Gunn and Rissmann 2025) - <a href='&amp' target='_blank' style='text-decoration:underline;'>Northland's Landscape Driven Erosion Map LWS 2025.pdf</a>Attribute fieldMultiple fields; see belowField descriptionFID: Internal feature IDOBJECTID: Polygon ID same as DRN catchment_2ha ObjectIDWatershedID: Unique Catchment_2ha watershed IDHydroID: Unique IDSlope_Mean: Mean slope of watershed (percent)Slope_Max: Maximum slope of watershed (percent)Elevation_Mean: Mean elevation of watershedElevation_Max: Max elevation of watershedRec2_SegmentID: Unique segment ID from parent REC ver.2 datasetRec2_ReachID: Unique reach ID from parent REC datasetUpstream_Slope_Mean: Mean slope of upstream contributing catchment area (percent)Upstream_Elevation_Mean: Mean elevation of upstream contributing catchment areaUpstream_Area: Total upstream contributing catchment area (m²)LU_Majority: Majority landuse value across watershed (Land Cover Database ver.5)HydroCat: Catchment nameShape_Length: Length in metreShape_Area: Area in sq. metreOLF_Classes_Majority: Majority class from OLF quantiles (1–5), where 1 = low and 5 = high overland flow riskSlope_Index_Mean: Mean slope-based index value (continuous). Values range from 0.15 (flat terrain) to 1.0 (very steep terrain).HYD_Index_Mean: Mean hydrological susceptibility index (continuous). Values range from 0.0 (low hydrological risk) to 1.0 (high hydrological risk).Regolith_Activity_Class_Majority: Majority class from inherent regolith activity quantiles (1 = most active, 5 = least active).`A70_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 rasterAuthorDr Clint Rissmann (Land & Water Science)ExtentWhole NorthlandProjectionNZTM (EPSG:2193)Coarsest Scale of Component Dataset1:63,000 soil derived informationVersionVersion 1.0Date CreatedJuly 2025Date ModifiedN/ANRC Team (if applicable)Natural Resources Science TeamSubject Matter ExpertClint Rissmann – Landscape ScientistFile Size4.35 GBVector Metadata SummaryCRS: NZGD2000 / New Zealand Transverse Mercator (EPSG:2193)Geometry: MultiPolygonStorage Format: GPKG (GeoPackage)Extent: 1567223.0000, 5971870.0000 to 1745598.0000, 6194217.0000Feature count: 417,938Encoding: UTF-8Data Provided by : Manas Chakraborty (Freshwater Resource Scientist)Data Published by: Bhawana Kafle (Geospatial Analyst)Data Published date: 19/02/2026Data Updated as Version 2: 06/03/2026</div></div></div>

Map Name: Erosion and sediment risk map

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Description: This vector dataset represents a polygonised summary of terrain, hydrological, and regolith susceptibility inputs over 2 ha DRN watersheds. It contains zonal statistics derived from continuous rasters and classed surfaces, used to evaluate spatial variation in erosion susceptibility at the subcatchment scale.Key attributes include majority values from classed S-PAL rasters (e.g. overland flow or OLF quantiles denoted by O, regolith activity quantiles denoted by A, S-PAL sibling classes), as well as upstream means of slope and elevation, and hydrological susceptibility indices (HYD and slope index).The symbology (erosion risk classes) of this vector layer is based on composite of two S-PAL factors - regolith activity (A) and overland flow (OLF) susceptibility at 50:50 ratio indicated by the attribute field ‘A50_O50_Quantile_Majority’.For details see the Land & Water Science report (Gunn and Rissmann 2025) - Northland's Landscape Driven Erosion Map LWS 2025.pdfAttribute fieldMultiple fields; see belowField descriptionFID: Internal feature IDOBJECTID: Polygon ID same as DRN catchment_2ha ObjectIDWatershedID: Unique Catchment_2ha watershed IDHydroID: Unique IDSlope_Mean: Mean slope of watershed (percent)Slope_Max: Maximum slope of watershed (percent)Elevation_Mean: Mean elevation of watershedElevation_Max: Max elevation of watershedRec2_SegmentID: Unique segment ID from parent REC ver.2 datasetRec2_ReachID: Unique reach ID from parent REC datasetUpstream_Slope_Mean: Mean slope of upstream contributing catchment area (percent)Upstream_Elevation_Mean: Mean elevation of upstream contributing catchment areaUpstream_Area: Total upstream contributing catchment area (m²)LU_Majority: Majority landuse value across watershed (Land Cover Database ver.5)HydroCat: Catchment nameShape_Length: Length in metreShape_Area: Area in sq. metreOLF_Classes_Majority: Majority class from OLF quantiles (1–5), where 1 = low and 5 = high overland flow riskSlope_Index_Mean: Mean slope-based index value (continuous). Values range from 0.15 (flat terrain) to 1.0 (very steep terrain).HYD_Index_Mean: Mean hydrological susceptibility index (continuous). Values range from 0.0 (low hydrological risk) to 1.0 (high hydrological risk).Regolith_Activity_Class_Majority: Majority class from inherent regolith activity quantiles (1 = most active, 5 = least active).`A70_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 rasterAuthorDr Clint Rissmann (Land & Water Science)ExtentWhole NorthlandProjectionNZTM (EPSG:2193)Coarsest Scale of Component Dataset1:63,000 soil derived informationVersionVersion 1.0Date CreatedJuly 2025Date ModifiedN/ANRC Team (if applicable)Natural Resources Science TeamSubject Matter ExpertClint Rissmann – Landscape ScientistFile Size4.35 GBVector Metadata SummaryCRS: NZGD2000 / New Zealand Transverse Mercator (EPSG:2193)Geometry: MultiPolygonStorage Format: GPKG (GeoPackage)Extent: 1567223.0000, 5971870.0000 to 1745598.0000, 6194217.0000Feature count: 417,938Encoding: UTF-8Data Provided by : Manas Chakraborty (Freshwater Resource Scientist)Data Published by: Bhawana Kafle (Geospatial Analyst)Data Published date: 19/02/2026Data Updated as Version 2: 06/03/2026

Service Item Id: 6d86e27a506849e09ded0b952e67faff

Copyright Text: Land & Water Science, NRC

Spatial Reference: 2193 (2193) LatestVCSWkid(0)

Single Fused Map Cache: false

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Units: esriMeters

Supported Image Format Types: PNG32,PNG24,PNG,JPG,DIB,TIFF,EMF,PS,PDF,GIF,SVG,SVGZ,BMP

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Supports Dynamic Layers: true

MaxRecordCount: 2000

MaxSelectionCount: 2000

MaxImageHeight: 4096

MaxImageWidth: 4096

Supported Query Formats: JSON, geoJSON, PBF

Supports Query Data Elements: true

Min Scale: 20000000

Max Scale: 0

Supports Datum Transformation: true

Child Resources: Info Dynamic Layer

Supported Operations: Export Map Identify QueryLegends QueryDomains Find Return Updates

Erosion_and_sediment_risk_map_v2 (MapServer)