1. Note to teachers This session is on river landscapes
– the geomorphic processes – have already been covered in the coastal landscapes revision
- the major river landforms
- the interaction of human activity on geomorphic processes
- applying the above to a case study of one river basin
The emphasis will be on key terminology and understanding how human activity affects the geomorphic processes.
For the case study students can choose –
either River Wye (Penguin texts pages 85-87)
or the River Eden (Revision Guide green book pages 36-38)
There is a handout sheet to accompany – 02.2 River Basin processes
This revision will be set as homework .

2. Geography GCSE Revision Distinctive Landscapes: Rivers
Learning outcomes
To outline the geomorphic processes shaping river landscapes
To understand the processes involved in the formation of major river landforms
To understand how geology, climate and human activity affect the geomorphic processes.
To apply the above information to a case study:
Either River Wye (Penguin texts pages 85-87)
or River Eden (Revision Guide green book pages 36-38)

3. The geomorphic processes – have already been covered.
They are the same processes that operate on coastal landscapes. You must ensure you understand them.
Weathering
Chemical
Mechanical
Biological
Mass movement:
sliding
slumping
Erosion
Hydraulic action
Solution
Abrasion
Attrition
Transport-ation
Solution
Suspension
Saltation
Traction
Deposition
Students use their own devices or any relevant textbooks
OCR GCSE textbook - penguin book - page 72-75
basics in Geog.2 not enough stuff on transportation If this is not going to be finished in the lesson it must be set as homework to complete

4. River basin terminology.
Make sure you understand each of the following…
- the river basin
- source
- mouth
- tributary
- confluence
- watershed
River basin – the area of land drained by a river and its tributaries. Also known as the ‘catchment area’.
Watershed – the high ground separating one river basin from another.

5. Tributary stream (a smaller river that flows into a larger river)
A TYPICAL RIVER DRAINAGE BASIN. THIS IS THE CATCHMENT AREA FOR ALL THE RAIN THAT FALLS WITHIN THE WATERSHED
Watershed
(higher ridge of land, the boundary between one drainage basin and another)
Confluence
(a place where two rivers meet)
Source
(the place where a river begins -a river system will have numerous sources, such as springs)
Tributary stream (a smaller river that flows into a larger river)

6. OVERGROUND All rain falling within a drainage basin is on a journey.
Some will transfer overground, on the surface.
OVERGROUND
Water runs downhill over the ground towards a river or stream. This is called -
SURFACE RUNOFF
Rainwater in a river or stream. This is called -
CHANNEL FLOW

7. Note: the level of saturation in the ground is called the water table.
Some will transfer underground, below the surface.
Raindrops INFILTRATE the soil and move downslope towards the river. This is called –
THROUGHFLOW.
UNDERGROUND
Water in the soil PERCOLATES into the rock. The water then moves slowly through the rock. This is called –
GROUNDWATER FLOW
Note: the level of saturation in the ground is called the water table.

8. Factors affecting the surface runoff.
Many factors will affect how much and how quickly water runs off.
These will be a combination of natural and human factors.
The climate (season) – summer or winter? e.g. in summer there is more evaporation and so less surface run off
The gradient (steepness) of the river basin. e.g. steep land = rapid surface run off
The climate (previous weather)
e.g. if the ground is already saturated any extra rain will run off.
The geology (porous or non-porous?) e.g. if the rock is non-porous then rain cannot infiltrate and will run-off the surface
Vegetation - many or few trees? e.g. if trees have been removed then there will be less transpiration and more surface run-off
Land use (Towns and cities) e.g. urban surfaces have lots of concrete and tarmac. Rain cannot infiltrate and so there is more surface run off.
River controls (Dams). e.g. Controls such as dams will regulate how much water is allowed to flow downstream.

9. Question: Explain the factors that have led to this flood. (4 marks)
Answer. This flooding has been caused by rapid surface run off. It is an urban environment with concrete and tarmac surfaces. These surfaces are impermeable so water cannot soak in (infiltrate). The lack of vegetation (trees and grass) also means that rainwater has not been transpired (absorbed). The drains have been unable to cope with the volume of water. The end result is a flash flood.
South London June 2016

10. Human activity in river basins and their impact on geomorphic processes. All human activities will have an impact on the geomorphic processes in the river basin. Here are 3 examples. It is important that you can explain the impacts using the correct terminology.
Agriculture. Farming will remove vegetation. There will be less transpiration. Ploughing may cause more soil erosion and mass movement. Surface run off increases and this will cause more discharge and erosion in the river channel.
Urban development. Towns & cities have more impermeable concrete and tarmac surfaces and fewer green spaces that absorb (infiltrate and transpirate) rainwater. This increases surface run off. More water in the river increases river erosion and flood risk.
River management. Dams, straightening rivers, building flood defences, will all affect the river channel processes. For example, building a flood barrier (embankment) will stop flooding and deposition but may cause the river to flow more quickly downstream, increasing the flood risk and river erosion and deposition elsewhere.

11. All river basins are affected by a variety of geomorphic processes.
For example -
Weathering: The heating and cooling of the rock
Weathering: freeze-thaw weathering on valley sides.
Mass movement: Gravity causing loose material to fall or slide
Erosion – of the river channel by hydraulic action, abrasion, etc.
Transportation. The river moving material by traction, saltation, suspension & solution
Garry - One could add “the 4 agents causing erosion on Earth are ice, rivers, waves and wind” This course just looks at rivers and waves as agents of erosion.
Biological weathering: Vegetation and animals, burrowing into the rock.
Deposition: Rivers depositing material where river energy is less.

12. Complete the handout sheet for your named river basin
Case study: You need a case study of a river basin.
Choose either - River Wye (Penguin texts pages 85-87) or River Eden (Revision Guide green book pages 36-38)
For the river basin you choose use the following slides to understand -
The landforms created by geomorphic processes
How the geomorphic processes operate at different scales and are influenced by geology and climate
How human activity, including management, impacts the processes and landscape
River Wye basin,
South wales & England.
River Eden basin,
Cumbria, NE England
Complete the handout sheet for your named river basin

13. Let us look at how geomorphic processes combine to produce some classic river landforms.

14. The journey of a river from beginning (source) to end (mouth) is called the long profile
Erosion will be significant in the upper course of the river. The steep gradient means the river will be down-cutting, causing vertical erosion.
Upper
Course

15. Landforms in the upper course
1) V shaped valley and interlocking spurs.
The gradient is very steep. The river is down cutting and eroding the channel by the process of hydraulic action and abrasion.
The valley sides are exposed to weathering, especially freeze –thaw (as its an upland area with a likely colder climate). Mass movement will cause this material to move down slope and enter the river channel. This will cause more river erosion by abrasion.
The river will wind around obstructions, forming a series of interlocking spurs.
Vertical erosion is dominant creating
a steep V shaped valley.

16. The source of the river, an upland area with high rainfall.
The river is down-cutting creating a steep, V-shaped valley, with interlocking spurs of land.
Evidence of vertical erosion. ‘White water’ and fast flowing

17. Landforms in the upper course
Waterfalls and gorges
Waterfalls occur when a band of hard rock overlays a soft rock.
The soft rock is eroded by hydraulic action caused by the force of the falling water and abrasion from material in the water. This creates a plunge pool with the hard rock overhanging.
In time the overhang of hard rock becomes more extreme and collapses. The waterfall retreats upstream, creating a steep cut in the land called a gorge.

18. WATERFALL
RETREATS . .
UPSTREAM . .
OVERHANG
PLUNGE
POOL
UNDERCUTTING
OF SOFT ROCK

19. River Landforms - Middle Course
Transportation. More material will be transported in the middle and lower course, but this material will get smaller in size.
Middle
Course

20. Meanders, river cliffs, slip off slopes and ox bow lakes.
The Middle course.
Meanders, river cliffs, slip off slopes and ox bow lakes.
Water does not flow in a straight line (even in a straight channel). The river’s flow takes a helicoidal (corkscrew) pattern. As a result water tends to zig zag in the channel.
Water, therefore, is more likely to erode one side of the channel, then erode the other side further down the channel. This causes bends to develop. These are called meanders.
Meanders are more likely when the river gradient is less steep and lateral erosion is more significant.

21. Meanders, river cliffs, slip off slopes and ox bow lakes.
The Middle course.
Meanders, river cliffs, slip off slopes and ox bow lakes.
As the water flows around the meander the outside of the bend will flow fast. The river will be deeper and erode the outside of the bend forming a river cliff.
On the inside of the bend the flow is slower. The river will be shallow and have less energy. Deposition will happen here, forming a slip off slope or river beach.
Over time the meanders become more exaggerated. The river may erode the bend so much it cuts off the meander, forming an ox-bow lake.

22. Middle Course - Meanders

23. The river is flowing in a wide flood plain
On the inside of the bend the river is slow and deposits material forming a slip off slope or point bar.
On the outside of the bend the river is fast, eroding the bank and forming a river cliff.

24. Sample question: Explain the processes involved in forming a river meander and describe how it is likely to change over time. Include labelled diagram(s) to help your explanation. (6 marks)

25. The Lower Course
In the lower stage the river is wide and deep and flows over a wide
floodplain (valley floor). The main landforms here will be formed by deposition.
Deposition. Deposition happens when the river loses energy. This can happen at all parts along the course but mainly when the river slows down (e.g inside of a river bend) and when the river meets a barrier (e.g. a dam or the sea). Therefore, deposition is more likely in the middle and lower course of the river.

26. River Landforms: Lower Course
In the lower course of a river the gradient is less steep. The river has less energy so deposition is more likely.
The main features in this part of the river are a wide flood plain and levees.
At the river’s mouth and estuary or delta may form.

27. Flood plains and levees.
The Lower course.
Flood plains and levees.
Floodplains and levees are formed by deposition in times of flood. The river’s load is composed of different sized particles. When a river floods it deposits the heaviest particles first. The larger, pebble sized particles, are deposited first. The medium sized sands are deposited next. Finally the lightest clays are deposited. Therefore the levee formed usually shows evidence of the sorting of different sized materials. This deposition makes up the floodplain.

28. The mouth of the river
Where the river meets the sea is called the river’s mouth.
If the mouth is wide is it called an estuary.
Very large rivers may bring down so much sediment that they
block their exit to the sea. The river divides into many
distributaries and a delta is formed.
The Thames estuary
The Nile delta

29. Some possible case study questions for Rivers.
Case study: For a named river basin in the UK, describe one landform formed by the action of the river. Explain the processes involved in forming this river landform and describe how this landform may change overtime. Include a labelled diagram.
 Case study: For a named river basin in the UK, explain how the geomorphic processes have been influenced by geology and climate.
Case study: For a named river basin in the UK, explain how human activity has affected the geomorphic processes operating in the river basin.

30. Model answer template: For a named river basin in the UK, describe one landform formed by the action of the river. Explain the processes involved in forming this river landform and describe how this landform may change overtime. Include a labelled diagram.
A river basin in the UK is … choose a named example and locate
One landform formed by the river is …. choose an example e.g. a waterfall or river meander
This landform is formed when …example below for a waterfall. A labelled diagram to accompany the explanation.
Over time this landform will change.
… a hard rock overlies a soft rock. The soft rock is less resistant and is eroded more quickly. This forms a step in the landscape. The water cascades over the step and hydraulic action creates a plunge pool. As rocks swirl about in the plunge pool the process of abrasion makes the pool deeper and undercuts the hard rock, making it overhang.
The hard rock will overhang even more and collapse. This causes the waterfall to retreat upstream, creating a steep sided gorge.

31. Distinctive Landscapes (Rivers)
Key vocabulary.
Use these terms in your writing
Distinctive Landscapes (Rivers)
Weathering
Mass movement
Porous
Impermeable
Slumping
Erosion – hydraulic action, abrasion, attrition, solution
Transportation – traction, saltation, suspension, solution
Geology
Deposition
Surface run off
Infiltration
Transpiration