This Combined Earthquake hazard shapefile is a compilation of all "combined earthquake hazard" ArcInfo coverages in major urban areas of the Wellington Region. The coverages represent overlays of all previous earthquake hazard data.1: Area of tsunami inundation2: 20m buffer along major fault traces3: Ground shaking4: Liquefaction potential5:Slope failure.The data was calculated using the following methodology:A 2-D database table (cell table, with 10m grids) that covers each map area was constructed. At the centroid of each cell, the relevant Arc-Info polygon attributes was assigned to a field corresponding to each hazard polygon. Calculations between each of these fields were carried out on a record by record (or grid centroid) basis.The calculations then followed for each hazard:• calculate the damage for each item of infrastructure for each hazard, based on the damage ratios given in Tables 6 through 10.• modify the liquefaction damage based on an assessed likelihood that liquefaction will occur in the area• total the damage for each hazard• add the damage for each hazard at each cell centroid to get the total damage due to combinations of hazard, a combined hazard index (CHI).These CHI values were then grouped into the severity using the CHI_HAZ_GR field, which was symbolised as the SEVERITY field. Map publication reference: WRC/RP-T-96/15 For notes on how this coverage was created refer to: Mapping methodology and Risk Mitigation Measures Publication: WRC/RP-T-96/22. Refer also to Consultant Ian R Brown Associates at

Dataset Attributes

  • CHI
    0 to 22480.5508
    1 to 5
    {"value"=>"3 Moderate", "count"=>6052} (), {"value"=>"5 High", "count"=>5001} (), {"value"=>"2", "count"=>3027} (), {"value"=>"4", "count"=>735} (), {"value"=>"1 Low", "count"=>147} ()
  • Shape
  • Shape.area
  • Shape.len

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