Edexcel Geography A GCSE - River Landscapes

River

A large natural stream of water that flows into the sea or another lake/river.

Source

Name for the start of a river.

Location of the source

Upland/ highland areas

Mouth

The end of a river.

Tributary

A river or steam flowing into a larger or main river flow.

Confluence

The point at which two rivers or streams join.

Drainage Basin

An area of land that is drained by a river. The area that gets flooded by the river during severe rainfall.

Gravity

Causes rivers to flow at a decreasing gradient.

Meanders

Curves in the river channel.

Course meanders are located in

Middle Course

Watershed

Marks the boundary between two drainage basins.

River Bed

The bottom of the river that can be made of stones, pebbles, boulders, rock, and/or mud; water in a river flows over the river bed.

River Bank

The sides of a river.

River Channel

The main path/course of the river.

Erosion (Rivers)

The wearing away of the river banks and bed.

The 4 main types of erosion

Hydraulic Action; Corrosion; Corrasion/Abrasion; Attrition.

Hydraulic Action

Build up of water pressure against the bank and river bed---> Air compresses into the cracks ---> more pressure ---> rock breaks.

Corrosion (or Solution)

Chemical reaction between certain types of rocks and the river water. This is mostly seen in limestone as the river eats through the rock and flows underground.

Corrasion

Particles and river material carried by the river and thrown against the river banks with force.

Attrition

Rocks in the upper course knock each other until smooth pebbles or sand is formed.

Weathering

Wearing away of materials due to the weather (e.g wind, rain, etc)

Upper Course

Steep as it's in the highlands; shallow as it's just starting; usually starts in a V shaped valley in highland; flows slowly due to friction between the water and the river bed (Uses 95% of the river energy); narrow.

Middle Course

Decreased gradient; increase in discharge due to tributaries; wider due to erosion; meander start to form.

Lower Course

Flat Land; river channel is wide; deep as it contains the highest amount of discharge.

Gradient

Steepness of the land.

Discharge

Amount of water in a river.

Velocity

Speed of the river.

River Erosion

Where moving water breaks down rocks into smaller chunks. Through either of the four processes (abrasion, attrition, hydraulic action, solution).

Narrow rivers

Have more friction so flow slowly.

Wide river

Have less friction so flow quickly.

Levees

Barriers composed of sediments made on either side of a river due to flooding.

Levees are found in...

Lower course

Interlocking spurs are found in...

Upper course

Oxbow Lakes are found in...

Middle course

Meanders are found in...

Middle course

V-shaped valleys are found in...

Upper course

Waterfalls are found in...

Upper course

Deposition

Process in which sediment is laid down in new locations.

Water Table

The level below which the ground is saturated with water.

Urban development and flooding

Development will increase the risk as impermeable surfaces cause rain to flow into river too quickly.

Tributaries and flooding

It will increase the risk as it will create higher discharge in the river channel meaning water travels too quickly through streams causing flooding.

Building roads and flooding

It will increase as permeable surfaces carry water more quickly.

Building dams and flooding

Dams lower risk as they control the amount of water entering the river.

Permeable rock and flooding

This lower risk, as rocks soak up water meaning water takes longer to get to the river.