Flood – Occurs when river discharge exceeds river channel capacity and water spills out of the channel into the flood plain and other areas

To remember the meaning of the term Flood, use the following mnemonic:

The great flood: When Noah saw that river discharge was exceeding river channel capacity he rather sensibly built an ark.

Floods are caused by heavy rainfall or the rapid melting of ice.

While this can cause major problems for people living and working in areas that are prone to flooding, floods have beneficial effects, too.

Floods deposit rich alluvium (deposits of clay, silt and sand) in agricultural areas, making the land more fertile; and flood water can replenish irrigation channels, again aiding agriculture.