Hazard Layers

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Hazard Layers

These are the hazard models that will cause the damage. Again several default models are supplied with RiskScape. A model can take a number of forms but realistically they are either a) pre-calculated exposure maps or b) a dynamic model that is run in real-time to calculate exposures in the requested area. User defined models of both kinds can be included in RiskScape, but the latter requires a high level of technical understanding of the RiskScape system and is best done in consultation with RiskScape. However a toolbox is provided to allow the import of pre-defined hazard maps to use as hazard models. Again the only constraint is that the exposures must comply with the RiskScape specification.

Hazard types and specifications

Access the hazard layer information via help desk request

Limits of Hazard Layers

Some layers are for training purposes

How to View Hazard Layer Metadata

Hazard parameters

These specify a set of necessary user input parameters for hazard models, e.g. an earthquake event can be specified by earthquake location, depth, magnitude and earthquake type (for application in an attenuation function to calculate ground shaking magnitude at an asset’s location). Hazard parameters are specific to the individual hazard Layer and can be defined in the RiskScape Hazard Layer specification generically as numeric and string parameters, or as lookup tables, and even as spatial input data sets (e.g. grids, shapefiles). The user interface is then built at run-time based on those specifications.

Hazard model

This is the actual core of the layer to calculate hazard magnitude at the locations of the assets. The implementation is layer specific and allows function calls of external hazard computer models (e.g. earthquake attenuation functions) or use of pre-computed hazard surfaces (e.g. scenarios of flood inundation for design or historic events). That also means externally modelled or observed scenarios, like satellite-derived inundation maps can be used as hazard models. This enables comparison of historic hazard scenarios with output from current hazard computer models.

Hazard exposures

Hazard exposures are defined as spatially explicit expressions of hazard magnitude returned from the hazard layer, for example, a map of ground shaking magnitude for an earthquake scenario, an inundation map for a historic flood scenario. This is the output of the hazard layer.

Hazard exposures need to be described by standard exposure types for the system to be able to display the data correctly (e.g. including units) and to calculate impacts and risks. The Hazards layer specification defines what type of hazard exposures the RiskScape software expects the Hazard model to return, and the software will change the user interface appearance accordingly (for example, display an inundation map and a legend as depth in meters).


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Tsunami Hazard

Tsunami Definition

Tsunamis are long wave-length oceanic waves generated by the sudden displacement of seawater by a shallow earthquake, volcanic eruption or submarine landslide.

New Zealand Tsunami Hazard Models

Canterbury and Kaiapoi Remote Chilean Tsunami

Canterbury Tsunami Model 1 in 2,500 year return period from South Peru

Otago

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Earthquake Hazard

Earthquake Definition

An earthquake is a sudden motion or trembling in the crust caused by the abrupt release of accumulated stress along a fault, a break in the Earth’s crust.

New Zealand Earthquake Hazard Models

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Storm Surge

Storm Surge Definition

New Zealand Storm Surge Hazard Models

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Flood Hazard

Flood Definition

A simple definition of flooding is water where it is not wanted. Another, more comprehensive definition of a flood is: A general and temporary condition of partial or complete inundation of normally dry land areas from the overflow of water bodies due to the unusual and rapid accumulation or runoff of surface waters from any source.

New Zealand Flood Hazard Models - Canterbury

New Zealand Flood Hazard Models - West Coast

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Wind Hazard

Wind Definition

There is no widely accepted definition for 'extreme wind'. In New Zealand, in the context of building design, an extreme wind is a wind gust which is strong enough to be dangerous for people, or cause significant damage to buildings and property.

New Zealand Wind Hazard Models

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Volcanic Hazard

Ash Fall Definition

When a volcano erupts, it will eject a wide variety of material into the air above it (called pyroclastic fall). The large fragments of material, 0.1 to 10 metres in diameter, rarely land more than 1-2 km from the vent. However the fine material (millimetre-sized ash), which is derived from volcanic glass, rock and crystal particles, can be carried by currents in the eruption column to high above the volcano and pass into the downwind plume to rain out forming ash fall deposits.

There are 12 active volcanic areas in New Zealand.

Although the probability of an eruption affecting a large area is relatively low in any one year, there is a range of volcanic eruption styles that are potentially hazardous to New Zealand communities. For most of New Zealand, volcanic ashfall (tephra) is the most likely volcanic hazard.

New Zealand Ash Fall Hazard Models

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