Wide valleys often include floodplains, which are broad strips of land built up by sediment deposition on either side of stream channels. During floods, floodplain areas may be covered by flood waters carrying silt and clay, which are deposited as horizontal layers when flood waters recede. Successive floods can build up natural levees, which are low ridges of deposited sediment forming along stream channels. Floodplains contain features such as meanders, point bars, and oxbow lakes.

1. BY:
THOMAS CHINNAPPAN . A ,
M.SC.APPLIED GEOLOGY,
PERIYAR UNIVERSITY,
SALEM.

2.  Wide valleys often include
 Floodplains
 Erosional floodplains
 Depositional floodplains
 Meanders
 Cut bank and point bar
 Cutoffs and oxbow lakes

4.  Flood Plain – is a broad strip of land built up
by sedimentation on either side of a stream
channel.
 During floods, flood plains may be covered
with water carrying suspended silt and clay.
 When the flood water recedes, these fine-
grained sediments are left behind as a
horizontal deposit.

5.  The sudden decrease in velocity of water
leaving the channel causes the river to deposit
most of its sediment near the main channel.
 Progressively less sediment is deposited away
from the channel
 A series of floods may build up natural levees
- low ridges of flood-deposited sediment that
form on either side of a stream channel

11.  Remnants of former floodplain
 River adjusts to drop in base level by
down cutting

14.  Occur where bed (sediment) load is very high.
Often big boulders in the stream.
 Many channels because mid-channel bars split
the stream.
 Adjacent to mountains in high rainfall areas.

16.  Definition: These are mounds of alluvium
(material deposited by running water) piled up
along the river's edge, each time the river
floods.