Natural hazards are naturally-occurring physical phenomena caused either by rapid or slow onset events having atmospheric, geologic and hydrologic origins on solar, global, regional, national and local scales. Natural hazards of geologic origin are earthquakes, volcanic eruptions, landslides, tsunamis, floods, drought.
Natural disasters are the consequences or effects of natural hazards.
They represent human, property and economic losses. They signify a serious breakdown in sustainability and disruption of economic and social progress. The overwhelming number of dead or seriously injured and homeless people after the occurrence of a natural hazard and the massive amount of money to be spent for reconstruction and rehabilitation equates to a natural disaster. Severe floodings are caused by deforestation. The impact of natural hazards to man can be reduced through better understanding of the geodynamic processes of natural hazards, worldwide dissemination of scientific knowledge, adoption of appropriate public and management policies and increase of awareness programmes and information campaigns.