Within the study of earth sciences, floods are potential natural disasters or hazards. 

Basically a flood is a when the water level in an area rises where there was normally little or none before. Floods can be dramatic and quick or slow and creeping.


A classic flash flood forming in a desert

Floods are usually natural phenomena common in many places around the world where either there is river nearby or the local weather can dump large amounts of rain.


A a diagram of a normal water level


A diagram of a flooded area, notice how the landscape changes.

The word 'Flood' comes from Old English, Flod, or Pleu, of an Indo-European language root.

Other uses of the word flood

There are many other uses of the word flood, which generally means a sudden increase in the amount of just about anything. Flood with light, flood the market with cheap goods and so on.


How floods occur


Floods are caused by excess water filling areas from a few main sources:

  • Rain fall (from …

How floods progress


Floods can progress at different speeds:

Fast floods or flash floods 

These often occur …