Natural earth processes or phenomena that may cause the loss of life or injury, property damage, social and economic disruption or environmental degradation.
Geological hazard includes internal earth processes of tectonic origin, such as earthquakes, geological fault activity, tsunamis, volcanic activity and emissions as well as external processes such as mass movements: landslides, rockslides, rock falls or avalanches, surfaces collapses, expansive soils and debris or mud flows.
A review presented at the first session of the Global Platform for Disaster Risk Reduction, held in Geneva from 5-7 June 2007, reported that changes in disaster risk are largely driven by the increasing vulnerability of nations and communities to natural hazards, arising from such underlying processes as rapid urbanization, unsafe land-use practices, environmental degradation, poverty and a lack of public awareness in regard to reducing disaster risks. Two broad risk scenarios are present: first, the risk of catastrophic disasters in areas of high risk, where people and economic activities are intensely concentrated in areas exposed to large-scale climatic and geological hazard events, such as earthquakes and tropical cyclones; and second, the risk of low-intensity asset loss and livelihood disruption over extensive areas, where people and economic activities are exposed to often localized hazard events, such as landslides, floods and droughts.