Geological Hazards, Risk Assessment and Planning

Geological hazards vary in their nature and can be complex. One type of hazard, for example, an earthquake, can be responsible for the generation of others such as liquefaction of sandy or silty soils, landslides or tsunamis. Certain hazards such as earthquakes and landslides are rapid onset hazards and so give rise to sudden impacts. Others such as soil erosion and subsidence due to the abstraction of groundwater may take place gradually over an appreciable period of time. Furthermore, the effects of natural geohazards may be difficult to separate from those attributable to human influence. In fact, modification of nature by humans often increases the frequency and severity of natural geohazards, and, at the same time, these increase the threats to human occupancy. 

If there are no mitigation measures, no warning systems and no evacuation plans for an area that is subjected to a recurring geohazard, then such an area has the highest vulnerability. 

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