This Slide share focuses on Stream valley development and about various stages of river. and concept of watershed from civil engineering point of view.

1. Dept. of MBA, Sanjivani COE, Kopargaon 1
Engineering Geology
( T.Y. B.Tech. Civil )
River Watersheds
Sanjivani College of Engineering, Kopargaon
Civil Engineering Department
Prepared By:
Dr. A. V. Deshpande
Ph. D (Geology), M.Tech (Env.Engg.)
Asst.Professor Civil Engg.Dept.
www.sanjivani.org.in

2. The streams
found in
mountains are
likely to have
formed
relatively
recently.

3. These young
streams
typically have
V-shaped
valleys.

4. The rivers tend to
move fast in their
upstream
portions,
although, some
are slowed by the
large rocks and
boulders in the
river channel.

5. The young
mountain
streams tend
to have a
steep slope or
gradient. Slope or
Gradient

6. OUTSIDE of River
Water velocity is
____________.
_____________
takes place.
INSIDE of River
Water velocity is
____________.
_____________
takes place.
FAST
EROSION
SLOW
DEPOSITION
A= Sediments are
eroded and carried
downstream
A’ = Sediments
are deposited.
EROSION-
Cut Bank
DEPOSITION-
Point Bar

7. DOWNCUTTING
Steep Gradient
Flows Straight
High Velocity
High Erosion
Rapids & Falls
Relatively
high
elevation
(mountains,
plateaus)
Gravity pulls
water to
lower levels.

9. Valleys with
very steep,
almost vertical
sides are
called canyons
or gorges.

10. How long do
you think it
took to form
the Grand
Canyon?

11. Most scientists
believe it took
1 to 3 million
years!

12. River bends
and loops
forming
Meanders.
•Not as steep
•Water velocity
slows down and
both Erosion &
Deposition occur.
•River is
established &
cuts into banks
creating a
floodplain
•Hills are
eroded
away.

16. Little or no slopes
near stream.
Wide flood plain on
the sides of river
Large meanders
may become
oxbow lakes
Low Erosion
and Mostly
Deposition
Stream has low
velocity.

19. Lower portions of rivers often start
to meander or form a s-shape river
pattern.

20. Erosion is greater on the outside of
the bend, deposition more on the
inside.

21. The river can eventually cut through
the meander, leaving a straighter
section and an ox-bow lake.

22. To view an animation of this
process click on this web site.
http://www.school-portal.co.uk/GroupDownloadFile.asp?file=21606

23. The river channel
becomes wider,
deeper, and the
volume is bigger
as there are more
tributaries
contributing to the
volume.

24. The lower or
downstream portion
of the river is at its
deepest, widest and
slowest speed.
It also has the largest
volume and a very
gentle gradient.

25. Rivers deposit the
sediment they
have carried as
they slow down.
This sediment
load will often
form deltas as the
river flows into
the quiet waters
of a bay or gulf.

26. The river tends to be
split into channels
by its own deposits
as it drops more
sediment.
As the deposits
grow, they
resemble the Greek
letter ▲(delta).

27. Alluvial Fans
An alluvial fan
differs from a
delta in several
ways.
The deposit is
formed on land,
not in water.

28. Alluvial Fans
Also, the
sediments of
these deposits
are coarse sands
and gravels,
rather than fine
silts and clays of
the deltas.

29. Watershed
A watershed, or
drainage basin
includes all of the
land that drains
into a river or bay
either directly or
through its
tributaries.

30. Watershed
The high land that
separates one
river valley or
watershed from
the next, is called
the divide.

31. •Narrow V-shaped
•Downcutting
•Swift water
•Steep gradient
•Erosion is dominant

35. • Erosion:
• In this picture, which
layers are being
eroded to cause
undermining?
• Kaaterskill Falls…

37. •Wide meanders and oxbow lakes
•Wide floodplain
•Low velocity
•Low gradient
•Dynamic equilibrium between erosion and
deposition

41. M
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