Thomas chinnappan geologist keeranur, pudukkottai, tamilnadu, india.

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.