A physical event, phenomenon or activity that has the potentially to cause the loss of life or injury, property damage, social and economic disruption or environmental degradation e.g. earthquake, flood, drought, tsunami, cyclone etc. Each hazard is characterized by its location, intensity, frequency and probability.

Classification of Hazards

On the basis of origin of the hazards:

1. Natural Hazards
   • Terrestrial hazards
     1. Endogenic Hazards
        • Volcanic
        • Earthquake
     2. Exogenic Hazards
        • Atmospheric Hazards
        1. Drought
        2. Rainfall
        3. Snowfall
        4. Winds
        5. Hailstorm
     • Hydrospheric Hazards
       1. Wave Currents
       2. Tsunamis
       3. Floods
     • Lithospheric Hazards
       1. Landslides
       2. Weathering
       3. Erosion
       4. Shifting
       5. Avalanches
     1. Biotic Hazards
     • Floral Hazards (Plants)
     • Faunal hazards (Animals)
     • Anthropogenic Hazards (Man Induced)
       1. Physical
       • Earthquake
       • Landslide
       • Erosion
       1. Chemical
       • Release of Toxic Chemical
       • Nuclear Explosion
     1. Biological
        • Eutrophication
        • Population Explosion
   • Extra-Terrestrial hazards

1. Natural Hazards

a. Terrestrial hazards

Those hazards which originate inside the earth or its atmosphere are called terrestrial hazards.

i. Endo-genic Hazards

Hazards which originate inside the surface of the earth are termed as endogenic hazards. E.g. Volcanic, Earthquake

ii. Exo-genic Hazards

Hazards which originate above the surface of the earth (in the atmosphere) are called exogenic hazards. These can be further sub-divided into the following categories:

A. Atmospheric Hazards

Natural hazards that originate in the atmosphere of the earth are called atmospheric hazards. These include cyclones, tornadoes, droughts, thunderstorms etc. Drought, Rainfall, Snowfall, Winds, Hailstorm

B. Hydrospheric Hazards

Those natural hazards that are related to water in the atmosphere are termed as hydrospheric hazards.  Wave Currents, Tsunamis, Floods

C. Lithospheric Hazards

Lithospheric hazards are those natural hazards that occur near to the surface of the earth. It includes the following hazards: Landslides, weathering, erosion, shifting, avalanches, sink Holes

Calcium carbonate inside the surface of the earth is dissolved by the underground running water and taken away with it, creating holes. This causes the earth to become hollow and eventually the earth above it settles down under load.

iii. Biotic Hazards

The types of hazards that originate through plants, animals or humans.

A. Floral Hazards (Plants)

The type of hazards that originate from plant life.

B. Faunal hazards (Animals)

C. Anthropogenic Hazards (Man Induced)

1. Physical

Earthquake, Landslide, Erosion

2. Chemical

Release of Toxic Chemical, Nuclear Explosion

3. Biological

Eutrophication, Population Explosion

b. Extra-Terrestrial hazards

The kinds of hazards which originate outside the earth and its atmosphere are called extra-terrestrial hazards. e.g meteorites.