1. Rivers
Chapter 7

2. Start on high, Flow down low, Creating features As they flow!
Rivers………
Start on high,
Flow down low,
Creating features
As they flow!

3. River Terms

7. Three stages of a river

9. Three stages of a river Youth Stage = Upper Course
Mature Stage = Middle Course
Old age Stage = Lower Course

10. The Work of Rivers

11. Stage Upper Course Middle Course Lower Course Slope Main processes
Valley shape
Main features

13. Stage Upper Course Middle Course Lower Course Slope Main processes
Valley shape
Main features

14. Processes of Erosion
How a river erodes

16. The Work of Rivers Processes of erosion: Hydraulic Action
The force of the moving water causes erosion of the river bed and the banks of the river. The greater the speed and amount of water the greater the force.

17. The Work of Rivers Processes of erosion: 2. Abrasion
The rivers load is bounced and dragged along the river bed causing it to scrape and deepen the course of the river.

18. The Work of Rivers Processes of erosion: 3. Attrition
The rivers load is constantly colliding in the moving river water causing the load to break down into smaller pieces.

19. The Work of Rivers Processes of erosion: 4. Cavitation
As a river flows over the uneven river bed air bubbles travel up to the top of the river, pop and send ripples out towards the river banks. These ripples gently erode the rivers banks.

20. The Work of Rivers Processes of erosion: 5. Solution
Chemicals in the rivers water and rocks along the river course change the river chemically which reacts with and erodes various rocks along the way.

22. How a river moves its load
Transport
How a river moves its load

24. Features

25. Describing a feature F.E.E.D
F: Feature (Name, erosion or deposition, stage it is found)
E: Explain with at least one or two processes explained
E: Three examples, one Irish
D: Clear 1/2/3 diagram/s to show how the feature is formed.

26. Three features we will study
Youth Stage = Waterfalls
Mature Stage = Meanders and Oxbow Lakes
Old age Stage = Deltas

27. Features of the Youth Stage
V – Shaped Valleys
Interlocking Spurs
Waterfalls

28. Interlocking spurs
A typical upper course V-Shaped valley with interlocking spurs, steep valley sides and active slope processes.
The diagram below shows the formation of interlocking spurs.

30. 1 2 3 4

31. Feature of Erosion Name Found Processes involved
Waterfall
Youth Stage
Hydraulic Action
Abrasion

32. Waterfalls f
Waterfalls are features of erosion usually found in the upper course (youth stage) of a river.
They are found in areas where a river is flowing over bands of hard and soft rock. The hard rock is slower to break down but the river can erode the soft rock much quicker. A band of hard rock lies on an area of soft rock. The river erodes the soft rock by the processes of hydraulic action (the force of the moving water) and abrasion (the scraping of the rivers load against the banks and bed). This causes a small notch to be formed into the soft rock which is eroded further into a drop over which the water falls. As the water falls over the drop there is a greater rate of hydraulic action and the rivers load also scrapes and deepens a hole in the bottom of the waterfall. This hole is called a Plunge Pool. The hard rock is slowly eroded and hangs over the edge called a Overhang. This is eventually worn down by the river and is carried away as the rivers load. e

33. e d Examples of waterfalls include: 1 2 3
Diagram of a waterfall being formed d

34. Victoria Falls, Zimbabwe Torc Waterfall, Killarney, Kerry
Examples
Angel Falls, Venezeula
Victoria Falls, Zimbabwe
Torc Waterfall, Killarney, Kerry

35. 1A2

36. 1A5

37. foe/sor
(e) px2
weu
Aoh/sr
srw
Waterfall
ucipp
neisr
rfovd

38. Waterfall foe/sor= Feature of erosion….stage of river pp@bow=
Weu=
Waterfall erodes upstream
(e) px2=
Erosion, Process are hydrualic action and abrasion
Aoh/sr srw=
Areas of hard/soft rock, soft rock weaker
Ucipp=
Undercut collapses into plunge pool
Waterfall
Neisr=
Notch eroded in soft rock
Plunge pool at base of waterfall
Rfovd=
River falls over vertical drop

39. Can you put the labels below into the correct place on he diagram?

41. Feature of Erosion and Deposition
Name
Found
Processes involved
Meanders and Ox Bow Lakes
Mature and Old Age Stage
Erosion and Depositon

43. Ox Bow lake on Mississippi

45. Describing a feature F.E.E.D
F: Feature (Name, erosion or deposition, stage it is found)
E: Explain with at least one or two processes explained
E: Three examples, one Irish
D: Clear 1/2/3 diagram/s to show how the feature is formed.

48. 1a2

49. 1a5

50. Describing a feature F.E.E.D
F: Feature (Name, erosion or deposition, stage it is found)
E: Explain with at least one or two processes explained
E: Three examples, one Irish
D: Clear 1/2/3 diagram/s to show how the feature is formed.

51. Deltas

54. Pg 37

55. Examples of deltas include:
The River Nile, Egypt
The Mississippi River in Louisiana, USA
The River Shannon in Limerick, Ireland

58. Humans and Rivers

59. New Orleans, Louisiana, USA
29th August 2005

61. New Orleans Video

64. Read Page 38-39 Name the river and the city of this case study?
The city is between two physical areas…what are they?
How is the city protected from flooding?
What did the President do to the amount of money available for protection of the land?
When did the disaster strike?
What was the name of the hurricane?
How many poor people could not leave the area?
How many people drowned in this disaster?

65. HEP: Hydro Electric Power
Electricity made by the power of moving water