This document discusses river landforms and processes. It begins by defining a river and explaining fluvial processes. It then discusses key aspects of river systems such as tributaries, floodplains, and meanders. Different drainage patterns like dendritic, parallel and trellis are described. The document also covers stream discharge, perennial and non-perennial streams, erosion types, sediment load and transportation methods. Finally, it summarizes the landforms created by upper, middle and lower course rivers such as V-shaped valleys, waterfalls, meanders, ox-bow lakes and deltas.

1. RIVER AND LANDFORMS
BY RIVERS
PRESENTED BY:
 ANAS ZAFAR

2. RIVER
A river is a natural flowing watercourse,
usually freshwater, flowing towards an ocean,
sea, lake or another river. In some cases a
river flows into the ground and becomes dry
at the end of its course without reaching
another body of water.
Example:
River Indus, River Nile, Amazon River,
Mississippi River.
Processes that are related to streams &
rivers are termed as “fluvial”.
Latin “Fluvius” =River
River Indus

3. RIVER INDUS

4. NILE RIVER
AMAZON RIVER

5. RIVER SYSTEM
A river system is sometime called Drainage system.
Every river is part of a larger system—a watershed,
which is the land drained by a river and its tributaries.
Rivers are large natural streams of water flowing in
channels and emptying into larger bodies of water.
This diagram shows some common characteristics of
a river system. Every river is different, however, so not
all rivers may look exactly like this illustration.
The truth is that rivers (like all other objects on
Earth) flow downhill due to gravity. No matter where
a river is located, it will take the path of least
resistance and flow downhill as rapidly as possible.

6. RIVER SYSTEM
The river source, also called the headwaters, is
the beginning of a river. Often located in
mountains, the source may be fed by an
underground spring, or by runoff from rain,
snowmelt, or glacial melt.
A tributary is a smaller stream or river that joins
a larger or main river.
The main river is the primary channel and
course of a river.
A fully-developed floodplain is relatively flat
land stretching from either side of a river, which
may flood during heavy rain or snowmelt. Built
of materials deposited by a river, floodplain soil
is often rich in nutrients and ideal for growing
food.

7. RIVER SYSTEM
A meander is a loop in a river channel. A
meandering river winds back and forth, rather
than following a straight course.
A river mouth is the part of a river where the
river debouches into another river, a lake, a
reservoir, a sea, or an ocean.
Upstream is in the direction of or nearer to the
source of a river.
Downstream is in the direction of or nearer to
the mouth of river.

8. DRAINAGE BASINS
Drainage is a term which describes the river system of an area.
A drainage basin is the area of land that it drained by a river and its tributaries.

9. DRAINAGE BASINS
WATERSHED - the area of high land forming the edge of a river basin
SOURCE - where a river begins
MOUTH - where a river meets the sea
CONFLUENCE - the point at which two rivers meet
TRIBUTARY - a small river or stream that joins a larger river
CHANNEL - this is where the river flows

11. DRAINAGE DIVIDES
In any drainage basin, water initially moves downslope as overland flow, which takes
two forms.
1)SHEETFLOW:
An overland flow or downslope movement of water taking the form of a thin,
continuous film over relatively smooth soil or rock surfaces and not concentrated into
channels larger than rills.
RILLS: A small channel or gulley, such as one formed during soil erosion.
2)CONTINENTAL DIVIDE:
A continental divide is a boundary that separates a continent's river systems. Each river
system feeds into a distinct ocean, bay, or sea.
Every continent except Antarctica has one or more continental divides.

12. Sheetflow Dinosour Provincal Park (CANADA)

13. Continental Divide

14. DRAINAGE PATTERN
The drainage pattern is the arrangement of channels in an area.
Distinctive patterns can develop based on a combination of
factors, including:
Regional topography & slope inclination.
Variations in rock resistance.
Climate.
Structure controls imposed by the underlying rocks.

15. TYPES OF DRAINAGE PATTERNS
1) DENDRITIC DRAINAGE:
Dendritic (Greek word DENDRON= TREE )
Dendritic drainage patterns are most common. They develop
on a land surface where the underlying rock is of uniform
resistance to erosion.
2) PARALLEL DRAINAGE:
A parallel drainage system occurs on a common slope down
linear ranges (or of rivers between linear series of parallel,
elongate landforms like outcropping resistant rock bands),
typically following natural faults or erosion (such as prevailing
wind scars).

17. TYPES OF DRAINAGE PATTERNS
3) RADIAL DRAINAGE:
Radial drainage patterns develop surrounding areas of
high topography where elevation drops from a central
high area to surrounding low areas.
NORTH ISLAND,
NEWZEALAND

18. TYPES OF DRAINAGE PATTERNS
4) TRELLIS DRAINAGE:
A trellis drainage pattern develops in area where the
geologic structure is a mix of weak and resistant
bedrock(such as in folded landscape).
5) RECTANGULAR DRAINAGE:
A rectangular stream pattern develops in areas where
there are jointed bedrock.

19. RECTANGULAR DRAINAGE TRELLIS DRAINAGE

20. A stream’s volume of flow per unit time is its distance
and is calculated by multiplying three variables
measured at a given cross section of the channel. It is
summarized in the simple expression.
Q= wdv
Where,
Q=discharge , w=channel width
d=channel depth , v=stream velocity
Discharge is measured in (m3/s or cms)&(ft3 or cfs).
STREAM DISCHARGE (THE VOLUME OF
FLOW)

22. PERENIAL & NON PERENIAL STREAMS
PERENIAL STREAMS:
Perennial rivers are those
rivers which exhibit a
continuous flow of water
throughout the year except
during extreme drought.
NON PERENIAL
STREAMS:
Non-perennial rivers are those
rivers which have no flow for
at least a part of the year.

23. STREAM ERROSION & TYPES OF ERROSION
Erosion is the process that wears away the river bed and banks. Erosion also
breaks up the rocks that are carried by the river.
There are four types of erosion:
Hydraulic action - This is the sheer power of the water as it smashes against
the river banks. Air becomes trapped in the cracks of the river bank and bed,
and causes the rock to break apart.
Abrasion - When pebbles grind along the river bank and bed in a sand-
papering effect.
Attrition - When rocks that the river is carrying knock against each other. They
break apart to become smaller and more rounded.
Solution - When the water dissolves certain types of rocks, eg limestone.

25. SEDIMENT LOAD
Solid particles produced by weathering and transported through a channel by stream
flow. The sediment load may be divided into two components: that which is suspended
within the water column, suspended sediment, and that which is moved along the bed
of a channel, bedload.
BEDLOAD:
Bedload is the portion of sediment transport that rolls, slides or bounces along the
bottom of a waterway.
Bedload refers to coarser materials that are moved by traction or by saltation.
SUSPENDED LOAD:
Suspended sediment are any particles found in the water column, whether the water is
flowing or not.
Suspended load consist of fine-grained clastic particles.

26. SEDIMENT TRANSPORTATION
TYPES OF TRANSPORTATION:
Traction - large, heavy pebbles are rolled along the river bed. This is most
common near the source of a river, as here the load is larger.
Saltation - pebbles are bounced along the river bed, most commonly
near the source .
Suspension - lighter sediment is suspended (carried) within the water,
most commonly near the mouth of the river.
Solution - the transport of dissolved chemicals. This varies along the river
depending on the presence of soluble rocks.

28. STREAM GRADIENT
Stream gradient is the grade measured by the
ratio of drop in elevation of a stream per unit
horizontal distance, usually expressed as
meters per kilometer or feet per mile.
A river has a steeper slope nearer the
headwater and a more gradual slope
downstream.
A stream gradient affects its energy and
ability to move material.

30. SEDIMENT DEPOSITION
BASE LEVEL:
The level below which a stream cannot erode its valley is base
level. In general, the ultimate base level is sea level.

31. SEDIMENT DEPOSITION
Deposition is the geological process in which sediments, soil
and rocks are added to a landform or landmass.
Why are Sediment Transport and Deposition
Important?
Many ecosystems benefit from sediment transport and
deposition, whether directly or indirectly. Sediment builds
aquatic habitats for spawning and benthic organisms. It is
also responsible for providing nutrients to aquatic plants, as
well vegetation in nearshore ecosystems such as floodplains
and marshes 10. Without sediment deposition, coastal zones
can become eroded or non existent.

32. LANDFORMS BY RIVER
The processes of erosion and deposition create
different river landforms.
River landscapes change as you go downstream
from the source to the mouth.
1) In the upper course of a river the altitude is
high and the gradient is steep.
2) In the middle course, the
river meanders through gentle gradients.
3) In the lower course, the river flows over flat
land.
UPPER COURSE
MIDDLE COURSE
LOWER COURSE

33. 1) UPPER COURSE RIVER
The gradient is really steep but the velocity
is slow moving because of the vast amount
of friction. They start off as streams
meaning very narrow and very shallow.
Also, because of the low amount of water
there isn't much discharge.
UPPER COURSE

34. LANDFORMS BY UPPER COURSE RIVERS
V-SHAPED VALLEY:
As the river erodes downwards the sides of the valley are exposed
to freeze-thaw weathering which loosens the rocks (some of which will fall
into the river) and steepens the valley sides.
The rocks which have fallen into the river assist the process of corrasion
and this leads to further erosion.
The river transports the rocks downstream and the channel becomes
wider and deeper creating a V-shaped valley.

35. 1 2
3

37. LANDFORMS BY UPPER COURSE RIVERS
WATERFALLS:
Waterfalls often form in the upper stages of a river where it flows over different
bands of rock. It erodes soft rock more quickly than hard rock and this may
lead to the creation of a waterfall.
Formation of a waterfall:
The soft rock erodes more quickly, undercutting the hard rock.
The hard rock is left overhanging and because it isn’t supported, it eventually
collapses.
The fallen rocks crash into the plunge pool. They swirl around, causing more
erosion.
Over time, this process is repeated and the waterfall moves upstream.
A steep-sided gorge is formed as the waterfall retreats.

40. 2) MIDDLE COURSE RIVER
The gradient starts to level off so the
velocity starts to increase because there is
less amount of friction acting on the water.
The river also widens because of erosion
because of faster moving water and
because it has more water and a larger
discharge.
MIDDLE COURSE

41. LANDFORMS BY MIDDLE COURSE RIVERS
MEANDERS:
A meander is one of a series of regular
sinuous curves, bends, loops, turns, or
windings in the channel of a river,
stream, or other watercourse. It is
produced by a stream or river
swinging from side to side as it flows
across its floodplain or shifts its
channel within a valley.

43. LANDFORMS BY MIDDLE COURSE RIVERS
OX-BOW LAKES:
An oxbow lake is a U-shaped lake that forms when a wide meander of a river is cut off,
creating a free-standing body of water.

45. 3) LOWER COURSE RIVER
The gradient levels off, but the speed of the
river is very fast because there is a low
amount of friction acting on the river water.
The river is very wide because of the vast
amount of water and the vast amount of
erosion that has occurred over the years.
The closer you get to the mouth of the river
the wider and deeper the river becomes.
The volume of discharge is extremely large
LOWER COURSE

46. LANDFORMS BY LOWER COURSE RIVERS
DELTAS:
The sediment is dropped at the mouth of
the river. Some rivers drop so much
sediment that waves and tides can't carry it
all away. It builds up in layers forming
a delta. Some deltas are so large that people
can live on them.

47. INDUS DELTA
SELANGA DELTA

48. THE END
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