Geohazards broadly fall into four categories, which range from single discrete geological events such as earthquakes, through various naturally occurring types of ground conditions, to legacies from human activities. Examples of these include: |
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Geological events
- Earthquakes
- Landslides
- Subsidence
- Volcanic activity
- Natural gas emissions including radon and methane
Geological processes and environments
- Faulting, folding and structural complexity
- Karstic, sabkha and playa environments
- Weathering, erosion and scour
- Karstic, voided and low-density ground
- Aggressive ground chemistry
- Artesian groundwater
- Contemporary and relic glacial and peri-glacial features
- Desertification and blowing sands
Characteristic soil behaviours
- Expansive/shrinkable soils
- Loess and other silt-rich soils
- Peat and organic-rich soils
- Running sands
- Soft clays
Man-made factors
- Ground contamination
- Groundwater abstraction/artificial recharge and de-watering
- Made ground, embankments, landfill and waste deposits
- Underground mining and well extraction
- Underground services, buried structures and obstructions
- Unexploded ordnance (UXO)
- Chemically/physically unstable materials such as expansive slags
- Thermally impacted ground such as cold-store freezing, furnace and
- kiln heating
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