The land you are referring to is commonly known as a "floodplain." Floodplains are areas adjacent to rivers that are periodically inundated with water during times of flooding. These regions are typically fertile and support diverse ecosystems, but they can also pose risks for human habitation due to the potential for flooding.
what is the level or nearly level land that borders a river and is covered by river water in flood time
The flood plain
A 'floodplain'.
A plain is basically a large, flat area and flood plains are the large flat areas to either sides of rivers. These areas, when it rains so much that the river bursts its banks, are covered in water: flooded.
a flood!
No, the area drained by a river is a river basin or drainage basin. The flood plain is in the lower valley reaches, where heavy rain can cause the river to flood, often bursting over flood defences, and for the water to flood over a large area.
The part of a river that is underwater when the river overflows its banks is called the flood plain.
A Flood.
called the floodplain, and it is typically covered with fertile soil deposited by the river during flooding events. Floodplains provide important habitat for wildlife and can also be used for agriculture and development, though they are at risk of flooding during periods of high water flow.
A plain is basically a large, flat area and flood plains are the large flat areas to either sides of rivers. These areas, when it rains so much that the river bursts its banks, are covered in water: flooded.
It's called a 'flood plain'.
Flood Plains