1. -We will revise the main topic areas of Water on the Land
Rivers Revision
-We will revise the main topic areas of Water on the Land

2. Knowledge Checklist Know the processes of erosion
Know the processes of transportation
Know how waterfalls and gorges are formed
Know how meanders and ox-bow lakes are formed
Know how flood plains and levees are formed
Know the factors that affect river discharge
Know the physical and human causes of flooding
Know a case study of a rich and poor country flood
Know how hard and soft engineering can be used in flood management
Know how water is used in the UK with areas of surplus and deficit
Know a case study of a reservoir in the UK

3. The Profile of a River
Key Idea: The shape of river valleys changes as rivers flow downstream due to the dominance of different processes.
Processes of erosion – hydraulic action, abrasion, attrition, solution; vertical and lateral erosion.
Processes of transportation – traction, saltation, suspension and solution.
Deposition and reasons for it.
Long profile and changing cross profile.

4. The Water Cycle
It is the main input to the drainage basin

5. The long profile and the drainage basin
The long profile of a river is a cross section from its source to its mouth. This whole area is known as the drainage basin.
They are divided into three sections:
Upper course
Middle course
Lower course
River gradient decreases gradually as the river flows downstream (ie. It becomes less steep)

6. Drainage Basin Key words
A river basin is the area of land drained by a river and its tributaries
Watershed – an area of higher land separating two drainage basins
Source – the place where a river begins
Tributary – a smaller river joining a larger one
Confluence – the place where two rivers join
Mouth – the place where a river enters a lake or the sea

7. Processes of Erosion

9. Transportation Material is carried in the river in four ways:
Traction: large stones are rolled along the river bed
Saltation: smaller stones ‘bounce’ along the river bed
Suspension: small particles of silt and clay float through the water
Solution: minerals are dissolved in the river

10. Deposition
Deposition is the dumping of material and happens when the river loses its energy. This may be during a dry spell, on the inside of a river bend, or when the river reaches the sea (read
on for more on this).

11. The Long Profile of a River
L.Ob: to describe how a river changes from source to mouth
Think about
the 2 pictures of rivers: why are they so different?

12. Features at the 3 stages of a river
Why?

13. Lateral & vertical erosion, transportation, deposition
UPPER COURSE
MIDDLE COURSE
LOWER COURSE
SOURCE
Lateral & vertical erosion, transportation, deposition
Transportation & deposition
Vertical erosion & transportation
MOUTH
V-shaped valley
Meanders
Ox-bow lakes
SEA
Waterfalls
Levees
Rapids
Flood plain
Interlocking spurs

14. River Severn – Source to Mouth Video

15. Upper Course Vertical erosion is the main process.
Valleys are v-shaped, interlocking spurs.
Waterfalls are formed.
Rapids are smaller scale feature formed where finer bands of varying resistance of rocks are found.

16. Foundation Question
Higher Question

18. Upper Course – V-Shaped Valleys and Interlocking Spurs

19. Upper Section Landforms

20. Waterfalls
A waterfall is a place on a river where the water flows vertically
They tend to occur in the upper course of a river
Softer rock erodes quickly, undercutting harder rock
Harder rock erodes more slowly, forming overhang
Overhang eventually collapses – the waterfall moves upstream
Steep sided valley (gorge) is formed
Plunge pool erodes under waterfall

21. Landforms in Middle and Lower Sections: Meanders

22. Formation of Meanders

24. Slow flow = loss of energy. Fast flow = lots of energy.
Low energy = deposition. High energy=erosion

25. Foundation and Higher Question

27. Meanders and Ox-Bow Lakes

29. Meandering stream
flowing from
top of screen
to bottom

30. Maximum
deposition
Maximum
erosion

40. Meander scars
Oxbow Lake
Oxbow
cuttoff

41. Foundation Question

42. Higher Question

44. A Delta
Some rivers reach the sea in deltas, which form where river mouths become choked with sediment, causing the main river channel to split into hundreds of smaller channels or distributaries
Deltas only form under certain conditions
The river must be transporting a large amount of sediment
The sea must have a small tidal range and weak currents
The sea must be shallow at the river mouth
Famous deltas consist of the Mississippi delta, The Ganges and Brahmaputra delta (Bangladesh) and of course the Nile delta.

45. Flood Plains and Levees
When a river continually floods, it spreads silt across the flood plain. Often this material piles up to form levees. Sometimes, humans make artificial levees to mimimise the impact of flooding.

46. Flood Hydrograph Peak Rainfall Peak Discharge LAG TIME
DISCHARGE (cumecs)
RAINFALL mm
time

47. River DISCHARGE
Discharge is the volume rate of water flow, which is transported through the river channel.
Measured in cumecs (cubic metres per second)

48. The Flood Hydrograph – A = floods quickly (flash flood) B = slower rate of discharge, less likely to flood
WHAT FACTORS AFFECT THE DISCHARGE LINE?

49. Factors Affecting Water in a River
Amount and type of rainfall
Previous weather conditions
Land use
Temperature
Rock type
Relief

50. Describe 5 factors that might affect the lag time (time it takes river to flood)

51. Describe 5 factors that might affect the lag time (time it takes river to flood)
1 = Deforestation
2 = Urbanisation
3 = Relief of land
4 = Dam Building
5 = Industry/Agriculture

52. Contrast the hydrographs (3)
Explain why the two hydrographs are different (4)

53. Foundation
Higher

54. Flooding Physical Factors Human Factors Prolonged Rainfall
Deforestation
Snowmelt
Impermeable materials
Heavy Rainfall
Relief
Frequency of Flooding
Flooding in the UK appears to be happening more often!

56. Case Studies You need to know too flood case studies!
Rich Country (Worcestershire, England)
Poor Country (Bangladesh)

58. Write a quick case study….
MEDC: UK Floods 2007
Write a quick case study….
What caused the floods? What were the main effects? What are the solutions?

59. FLOODING IN AN LEDC – Bangladesh Case Study
IMPORTANT DATES and DEVELOPMENT INDICATORS for Bangladesh
CAUSES of the flood:
MANAGEMENT RESPONSES – can they reduce the impact?:
EFFECTS of the flood on People and Environment:
Remember SHORT and LONG TERM

60. Hard Vs Soft Engineering
Page 92 of book
Raise levees
Dredge river beds
Straighten rivers

61. Hard Vs Soft Engineering
Zone off some areas
Better warning systems

64. Model answers and mark scheme
For more past papers and info visit the OCR ‘A’ Geography website

65. Managing Water in the UK
What causes the water stress?
How can we be more efficient with water?

66. (6)

67. Reservoir Case Study
You need to know one case study of a reservoir that provides water to people in the UK
Kielder Reservoir is in book
Biggests man-made reservoir in Europe.
Was poor farmland, large valley with steep sides.
Lots of rainfall and low population.
Wild habitats were limited so little environmental damage.
Supplies NE of England wit water.
Lots of leisure industry there. Good for economy.

70. Click for examiners mark scheme
Past Paper Questions
Click for examiners mark scheme

71. Model answers and mark scheme
Continues…..

72. Model answers and mark scheme
Continues…..