Name: Blue Zone

Display Field: Shape_Length

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: The Northland Tsunami Evacuation Zones 2024 have been prepared by Jose C. Borrero Ph.D. (ORCA Consulting) for Northland Regional Council, based on numerical modelling and analysis.The objective was to produce tsunami inundation and evacuation zones for the Northland region that are compliant with guidelines set forth in the document ‘Tsunami Evacuation Zones: Director’s Guidelines for Civil Defence Emergency Management Groups’ (MCDEM, 2016). This document defines three tsunami evacuation zones: Red, Orange, and Yellow. The Red Zone is the area closest to the coast which would be evacuated in most tsunami warning situations. The Orange Zone is an intermediate zone that considers tsunami hazard from either large tsunami sources located far away or moderate tsunami sources close by (but more than 1 hr travel time away). The Yellow Zone represents the area to be evacuated in the most extreme scenarios of a very large near-source earthquake. This Blue Zone is an amalgamation of the Red, Orange and Yellow Zones.Numerical modelling determined that the most extreme hazard, the one which governs the Yellow Zone for the east coast, is represented by a large rupture of the southern segments of the Tonga Kermadec Trench. For this scenario we modelled rupture over a 400x100 km fault plane with average slip amount of 30 m. As a matter of comparison, we note that this source is slightly larger in terms of areal extent and average slip then the 2010 Tohoku Japan earthquake and tsunami. For the Orange Zone, we determined that the hazard was best represented by aggregating the inundation results from a suite of large magnitude, distant and regional source earthquakes. In this case, simulations that produced anomalously large tsunami heights either at the shoreline or at the offshore location were not used in the aggregation. All in all, the final inundation zones correspond best to a tsunami threat level of 3-5 m as defined in the DGL. Raster files of tsunami inundation flow depth and inundated area were compiled for each of the 60 high resolution model grid regions for the Yellow and Orange Zones. This raster data was transferred to GIS for processing into the inundation zones, creating continuous Orange and Yellow Zones as well as the Red Zone. The Red Zone was creating on the same criteria as Auckland Council for cross boundary consistency, based on 100m buffer for rocky and steep coasts, and +2m elevation contour for all other areas. The final Red Zone was created on the greatest inland extent. Gaps between the red and yellow zones and red and orange zones were filled in to create a continuous zone. For tsunami inundation zones at the model tile edges, zones were extended based on the corresponding contour height.

Service Item Id: ac0f30c667cb4e57976bbf2b94b86a28

Copyright Text: ORCA Consulting

Default Visibility: false

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 0.0

Max Scale: 0.0

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: 1566454.9737
YMin: 5971835.1409
XMax: 1760956.8203999996
YMax: 6194224.1447
Spatial Reference: 2193  (2193)  LatestVCSWkid(0)

Drawing Info:

Renderer:
Simple Renderer:
Symbol:
Style: esriSFSSolid
Color: [0, 197, 255, 255]
Outline:
Style: esriSLSSolid
Color: [0, 169, 230, 255]
Width: 0
Label: N/A
Description: N/A
Transparency: 45
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: 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 )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• Zone ( type: esriFieldTypeString, alias: Zone, length: 10 )
• 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