The document details the characteristics and processes of rivers, including their longitudinal profiles, methods of erosion like hydraulic action, attrition, and corrosion. It explains the formation of various landforms, such as valleys, gorges, canyons, and waterfalls, resulting from water flow and geological factors. Additionally, it discusses sediment transport and depositional features like alluvial fans, cones, and deltas.

1. H.N.B.G.U
Srinagar, U.K
River
by
Anuj Yadav (M.SC.1)

2. RIVER

4.  Every River Channel is Characterized with
a Longitudinal ( Lengthwise ) Profile
 Head Region Is the Highland Region from
where the River Originates.
 Then River Flows Through Gradually
Decreasing Slopes and then through nearly
Flat Lands
 Mouth is The Place where River Enters a
Sea .

5. While river flows through Head to mouth, It
Exerts Great Influence over topography.
 Basic Terms :-
 Channel
 Velocity
 Gradient
 Type of flow

6.  Hydraulic action
 The work of turbulence in the water.
 Running water causes friction in the joints of rocks
in a stream channel
 Joints may be enlarged
 Loosened fragments of rocks get swept away.
 Attrition
 When thrown against the sides and bed of rivers,
the load gets broken into smaller pieces.

7.  Corrosion
 Certain minerals in rocks like limestone can be
dissolved in water.
 Rocks are then eroded.
 Abrasion
 Load carried by a river will grind against its bed
and sides.
 This process slowly wears the bed and sides away.

8.  Potholes
 River Valley
 Gorges and Canyons
 Waterfall

10.  They are variously shaped depressions of
different dimensions
 Formed by plucking of an outstanding rock
projection, resulting in small depressions
 Abrasive action, on depressions leads to
further deeping and widening of potholes

12.  Area of low land surrounded on sides by
inclined hill slopes and mountains.
 Origin, development and modification of
valley, depends on river flowing through it.
 Valley formed in the youthful stage of fluvial
cycle of erosion and in the initial stage of
valley development is V shaped having steep
side valley slope of convex element.
 The valleys are gradually widened due to
lateral erosion.

15.  The process of valley deepening often gives
rise this type of surface feature
 Gorges are very deep and narrow valleys with
very steep and high walls on either side.
 Canyon is a specific type of george where the
layers cut down by a river are essentially
stratified and horizontal in altitude.
 Canyon has been formed through a long
period of time and frequent erosion from
plateau.
 Gorges are normally formed from the flow of
water.

17.  Waterfalls are free flowing water columns
 They are attributed to unequal erosion of the
channel rocks with the weaker rock being eroded
much faster, creating a depression just ahead of
resistant ledge.
 They reflect geological control.

18.  Suspended Load
 Bed load
 Dissolved Load

19.  A river will drop its load when:
 Volume decreases
 Speed decrease
 A river’s volume decreases when
 Dry season
 Dry region with high evaporation
 Presence of permeable rocks
 Receding flood waters

20.  Alluvial fans and cones
 Flood Plains
 Deltas
 Oxbow Lakes

22.  Alluvial fans and cones are always formed at
base of foothills where there is abrupt drop in
channel gradient.
 Alluvial fans have gentle slope below 10
degree, and alluvial cone has a slope in range
of (10-50 degree).
 Alluvial cones are made of coarser material
than alluvial fans.
 There may growth of a fan by repeated
accumulations, Upwards as well as Laterally.

25.  The depositional feature of almost triangular in shape
debouching either in a lake or a sea is called Delta.
 The term delta was first used by Herodotus for triangular
landform at mouth of Nile river.
 Delta is made of three layers
• Bottom set beds
• Fore-set beds
• Top-set beds.