a natural hazardis a natural phenomenon that might have a negative effect on humans or the environment. natural hazard events can be classified into two broad categories: geophysical and biological. geophysical hazards encompass geological and meteorological phenomena such as earthquakes, volcanic eruptions, wildfires, cyclonic storms, floods, droughts, and landslides. biological hazards can refer to a diverse array of disease, infection, and infestation.
many geophysical hazards are related; for example, submarine earthquakes can cause tsunamis, and hurricanes can lead to coastal flooding and erosion. floods and wildfires can result from a combination of geological, hydrological, and climatic factors. it is possible that some natural hazards are intertemporally correlated as well. an example of the distinction between a natural hazard and a natural disaster is that the 1906 san francisco earthquake was a disaster, whereas living on a fault line is a hazard. some natural hazards can be provoked or affected by anthropogenic processes (e.g. land-use change, drainage and construction).