A small river or stream that
joins up with a larger one
Confluence
The point at which a
tributary joins the river
Mouth
The point where a river
enters the sea
River Basin
An entire area
drained by a river
and its tributaries
Watershed
High ground that
separates one river basin
from another
Stages in a river's
course
Youthful
Stage(lower
course)
The river has a
steep gradient
(slope)
The valley has a
narrow floor and
steep sides
Mature
Stage(middle
course)
The river has a
gentler gradient
The valley has
a wider floor
and the sides
are more gently
sloping.
Old stage(upper
course)
The river has an
almost flat gradient
The valley has a
wide, flat floor and
gentle sides
River processes
of Erosion
Hydraulic action
The force of the moving
water that helps break up
rock over time.
Abrasion
When the material(the load) carried
along by the river hits its banks and bed,
wearing them away.
Attrition
The rounding of pebbles, stones
when they hit off each other and the
river bed as they move downstream.
The river deposits
its load when:
It loses speed and
has less energy.
The river's volume
decreases.
It enters a flat or
gently sloping plain.
It flows into a lake or
the sea.
River Transportation
Suspension
Particles are lifted and
carried by the river water.
Saltation
Particles are bounced
along the river bed.
Traction
Large stones are
dragged or rolled along
the river bed.
Solution
Some minerals, such as calcium
carbonate (limestone), are
dissolved in the water.
Features of the
Youthful Stage
V-shaped valley
Interlocking spurs
Waterfalls
Gorge
Potholes
Features of the
Mature Stage
Wider Valley
Meanders
Narrow flood plain
Features of the
Old Stage
Oxbow lake
Levees
High banks along the river's
channel. They form from river
deposits
Delta
Form where some rivers
enter the sea. They are often
triangular in shape. They
form from river deposits,
which are deposited when the
river slows down as it enters
the sea
Large Meanders
People Interfere with rivers
by building dams or
man-made levees
Rivers interfere with
people by flooding.
1. Towns, villages
and individual
houses may be
flooded when rivers
overflow their banks
2. Crops such as cereals and
hay may be damaged on flood
plains
3. Floods may
sweep away
bridges, walls
and people's
homes
Advantages of river valleys to people
1. Flood plains are used
to grow some kinds of
crops and rear animals
for food
2.Level land in
valleys is used to
build towns and cities
3. Early settlers used
riverside sites for water
supply, food supply and
transport facilities on the river.
4. Norman settlers
used rivers as a mode
of defense around
their castles
5. Shallow places in rivers
were used as crossing points.
Most of our towns and cities
developed at crossing points