Natural hazard definitions


Flooding is the covering of normally dry land as the result of extreme rainfall.  Flood modelling shows which areas might be flooded in an extreme rainfall event and to what depth.​

Coastal inundation

Coastal inundation is flooding from the sea.  Coastal inundation modelling shows which areas might be flooded in the event of a storm surge and to what depth they may be flooded.

Coastal erosion

Coastal erosion is the loss of land due to coastal processes such as waves and tidal currents wearing away that land suddenly or overtime.

Land instability

Land instability refers to land which has the potential to slip when saturated with water.  Generally, it is steep slopes and cliffs prone to slipping.


Liquefaction happens when saturated soils lost strength and stiffness (behaving as liquid                                     rather than a solid) in response to earthquake shaking.


A tsunami is a series of waves generated when a large volume of water in the sea is rapidly displaced.

Want to know more about each of these natural hazards and how to prepare for them in an emergency? Visit the Bay of Plenty Emergency Management website.​

Page reviewed: 18 Feb 2020 2:56pm