1. River Studies 3: The 3 courses of a river

2. Over the next few lessons we will learn about the different
The 3 courses of a river.
Lesson aims:
Over the next few lessons
we will learn about the different
courses of the river.
Rivers have 3 main course:
The upper course
The middle course
The lower course

3. THE RIVER MODEL Source of river Upper Course Middle Course Lower

4. The upper course of the river
V-Shaped valley
with steep sides
Large load
(eg big rocks)
The upper course of the river
Fast flowing water
Lots of
vertical erosion
Task:
Look at the picture that comes up and write down everything you can see in it.
Think about the shape, the speed and the load.
Lots of “energy”
in the water
Interlocking
Spurs
Shallow water

5. A typical upper course valley with interlocking spurs, steep valley sides and active slope processes

6. What do you think the land here could
River features
Characteristics
Upper Course
Middle Course
Lower Course
Depth
Shallow
Width
narrow
Speed
Fast
What do you think the land here could
be used for by people?
Straightness
winding
Load
Type of load
large
angular
Features
V-Shaped Valleys, Interlocking Spurs,
Waterfalls
Land Use

8. Land Use in the Upper course
Gorge-walking
Hill sheep farming
Hydro-electric power (HEP) reservoirs
Rock Climbing
(No crop farming as the land is too steep, not many roads and communication links)

9. Formation of a V-Shaped Valley
This is VERY IMPORTANT as it comes up all the time!
When doing this you must:
Draw at least 3 diagrams
Label the diagrams
Have some text explaining what is happening

10. Terms you need to know Vertical erosion Hydraulic action
Freeze thaw action (Weathering)
Mass movement

11. Freeze Thaw When water gets into cracks in rocks and then freezes.
This causes it to expand and then break the rocks apart.

12. Mass-movement.
This is when gravity pulls material down slopes.
It causes rocks to fall into the river.

13. Task part 1 Diagrams
You are going to be given a textbook answer to the formation of a V-shaped valley.
You must come up with the 3 diagrams that will help you to explain what is going on.
To do this collect a mini white board.
2 minutes to read through the text.
5 minutes to come up with 3 diagrams.

14. HYDRAULIC ACTION SOLUTION ATTRITION ABRASION
Quick test
HYDRAULIC ACTION
SOLUTION
ATTRITION
ABRASION
The force of the water weakens and breaks up the rocks.
The water in the river dissolves the minerals in the rocks
As the pebbles carried by the river crash into each other, they become smaller and rounder
The material carried in the river wears away the river bed

15. Suspension
Traction
Solution
Saltation

16. Diagrams 1 2 3

17. Task part 2 labels Now you have the diagrams and the text
The next thing you need is detailed labels.
Using the paper you have been given in two’s write on all of the labels you can think of.

18. Labels for a V-shaped valley.
The fast flowing river begins to erode the valley
Processes such as abrasion/corrasion take place
Valley start of with slightly sloped sides.

19. Mass movement begins to weaken the material at the sides of the valley.
Vertical erosion takes place eroding the valley downward.
Weathering (freeze thaw) weakens the valley sides.
Hydraulic action takes place wearing down the rock.

20. Eventually the material is weakened so much it falls into the river
The fast flowing river transports much of the material
A V-shaped valley is left with steep sides

21. You also have to write some text
The example you have in your jotter is a good one but it could be simplified.
Read over it and try and turn it into 4 sentences.

22. Interlocking spurs are formed when the relief of the land changes
and therefore the river
changes direction
Formation of interlocking spurs:
Interlocking spurs are formed exactly the same as
a V-shaped valley. (so you would start
with the same diagrams and text.)
This may also occur if
the river hits a large rock
or area of hard rock it can’t erode.

23. Next Feature.
Waterfalls

25. Waterfall 1) Water flows over hard rock and then onto soft rock
2) Over time the soft rock is eroded
3) A waterfall is created

26. Watch waterfall video

27. Formation of a waterfall
Retreats upstream
Hard rock
Soft rock
Steep sides
( gorge )
Undercutting
erodes the
softer rock
forming an overhang
The overhang
Eventually
collapses
The process
starts again
Vertical erosion
Forms plunge pool
Eroded rock

28. Waterfall Formation
Water flows over areas of hard rock and onto soft rock
Eroding the soft rock more quickly.
Over time the hard rock sticks out over the soft rock.

29. This area is called the plunge pool.
River Landscapes Standard Grade
The soft rock underneath is eroded further by the force of the water (hydraulic erosion).
This area is called the plunge pool.

30. The waterfall continues to move upstream over
River Landscapes Standard Grade
In time the hard rock above the plunge pool collapses falling into the plunge pool
The pieces of hard rock help to erode the plunge pool further (corrasion) and are themselves eroded by attrition.
The waterfall continues to move upstream over
time forming a gorge.

31. UPSTREAM . . WATERFALL RETREATS . . OVERHANG PLUNGE POOL UNDERCUT
SOFT ROCK

32. Waterfall video again

33. Middle course of a river.

37. What do you think land use could be this time?
Key features:
Everything is medium:
The width is medium
The depth is medium
The speed is medium
The type of load is small and medium rounded rocks. (no big rocks)
Land is quite flat. Although you may get slight hills at edges.
It has meanders (bends in the river)
What do you think land
use could be this time?

38. Land use
Settlement - towns built on flat land near river bridging point. Routes along the valley often meet at bridges.
Farming - on flat valley floor where soils and weather are better.
Tourism - farmers provide simple accommodation (B&B, caravan, camping) to supplement their income. Middle course location provides tourists with access to both uplands and lowlands.
Fishing - good source of income for landowners, especially in salmon rivers.

39. Formation of a meander. Important points.
Erosion occurs on the OUTSIDE of bends.
Deposition occurs on the INSIDE of bends.

40. Take the title Formation of a meander.
Lesson starter:
Take the title Formation of a meander.
Take half a page in your jotter and draw a river along it.
Then swap it with the person next to you and they have to draw on the areas of erosion and deposition.

41. Formation of a meander. It’s the same as all other features: Diagrams
Labels
Text

42. I am going to give you the text.
Your task it to draw the diagrams.
Collect a whiteboard and pen.
For each of the statements you see you must draw one picture.

43. Diagram sheet
1) As a river moves down stream is does not flow straight, it curves slightly. This is because it will follow the easiest route and due to it flowing faster in some paces than others.
2) The river flows faster on the outside of these curves and slower on the inside.
2) Due to this we get erosion on the outside of the curves and deposition on the inside of them.
3) Over time this erosion and deposition causes the river to bend.

44. Diagram sheet
4) The erosion continues and the curve becomes bigger. The ares of erosion and deposition become bigger too.
5) Eventually large meanders are left in the river. They continue to grow as the erosion and deposition get greater.

47. River bend Fastest current slowest current Bank will collapse Small
cliff
Slip off slope
( river beach )
Deposition of
Sand and shingle
Outer bank
Is undercut
Deepest part
of the river

48. Quick quiz: part 1
Erosion Or
Transportation

49. Get a whiteboard and pen.
On one side write erosion.
On the other side write transportation.

50. Corrasion Corrasion – rivers use the stones and pebbles they
carry (its load) to smash against the sides and bottomof the river.

51. Hydraulic action
Hydraulic Action - the sheer force of the water causes the outer banks of the river to break up and collapse. It is most effective in times of flood.

52. Traction Traction – the largest boulders roll
along the river bed at times of flood
when the energy level in the river is high.

53. Attrition Attrition - the stones and pebbles the river carries
(its load) rub against each other.
Over time the size of this load becomes smaller and
more rounded.

54. Saltation
Saltation – larger particles bounce along the river bed. These particles can cause other larger particles to become dislodged

55. Quick quiz part 2
You are going to see a statement.
You must draw a picture that goes along with it.

56. V-shaped valley The valley starts of with gently sloping sides.
Fast flowing water begins to erode the valley vertically.
Processes such as abrasion take place as the rocks in the river are transported.

57. V-shaped valley Hydraulic action makes the valley deeper.
Mass movement and freeze thaw action make the sides of the valley weak.
Vertical erosion takes place.

58. Waterfall
Water flows over hard rock then onto soft rock. The soft rock is eroded more quickly.
Overtime an overhand and plunge pool are formed.

59. Waterfall
The rocks in the plunge pool as well as vertical erosion cause the soft rock to erode backwards.
The overhang becomes too heavy and eventually falls.

60. Homework: Tuesday 27/03/2012
Explain the formation of a v-shaped valley and a waterfall. You may use diagrams to in your answer.
8 KU

61. Number 2: What are the characteristics of the rivers middle course?
Lesson starter.
With the person beside you each take a number 1 or 2.
You will take turns explaining the features of a river of river course to ach other.
Number 2: What are the characteristics of the rivers middle course?
Number 1: Explain how a meander is formed.
Number 1: Explain how a v-shaped valley is formed.
Number 2: Explain how a Waterfall is formed.

62. The lower course of a river
You are going to see a picture of the lower course of a river. Using this and your new knowledge of rivers you must write down what you think the characteristics of the river will be. Include:
Its width
Depth
Speed
Load (amount and type)
The land around it.
Features
Land use

63. Width
Depth
Speed
Load (amount and type)
The land around it.
Features
Land use

65. Lower Course of the river features:
Its width:
Very wide
Depth
Very deep
Speed
Slow
Load (amount and type)
Large load (lots of it), but small rocks, sands ad silt.
The land around it.
Large flat flood plain
Features
Ox-bow lake.
Delta
Mouth of river.

66. Land use
Large settlements. Transport routes. Industry. Ports for trade.

67. Mystery feature:
How were these features formed on the landscape?

68. The formation of an Ox-bow lake.
Occasions