Water on the Land

Page 1

The River Valley

Course

Upper

Middle

Lower

Gradient

Steep

Medium

Gentle

Valley and channel shape

V-shaped valley, steep sides. Narrow, shallow channel

Gentle sloping valley sides. Wider, deeper channel

Very wide, almost flat valley. Very wide, deep channel

Processes of erosion:

Hydraulic Action - The force of water breaks rock particles away from the river channel

Abrasion - Eroded rocks picked up by river scrape along channel, wearing away

Attrition - Eroded rocks picked up by river smash together and break into smaller pieces

Solution - River dissolves some types of rock (e.g. chalk and limestone)

Types of transportation:

Traction - Large particle like boulders are pushed along river bed

Saltation - Pebble sized particles are bounced along the river bed

Suspension - Small particles like silt and clay are carried along by the water

Solution - Soluble materials dissolve in the water and are carried along

Deposition:

Deposition is when a river drops eroded material it's transporting

Reasons for deposition:

The volume of water in the river falls

The amount of eroded water material in the water increases

The river is shallower#The river reaches its mouth

Meanders

The current is faster on the outside of the bend because the river channel is deeper

Oxbow Lake

Waterfalls

Gorges

Floodplain - the wide valley floor on either side of a river which occasionally gets flooded

Levées - natural embankments (raised bits) along the edges of a river channel

Both are found in the lower course of a river

Both are found in the lower course of a river

Erosion

The River Valley

Erosion

River Landforms

River Landforms

Floodplain and Levees