Definition: A flood plain is an area of flat land alongside a river. This area gets covered in water when the river floods. Flood plains are naturally very fertile due to the river sediment which is deposited there. This sediment is good for growing plants on the flood plain. But flood plains can also be very dangerous places. Even though they regularly flood, houses are often built on them.
River and floodplain area
Image courtesy of Ade Cousins - click to enlarge
Waters rising
Images courtesy of Victoria Finn, 2019 - click to enlarge
Flood plain during high flood
Images courtesy of Tom Blockley, 2019