This document discusses water on the land and how rivers change from their source to their mouth. It explains that rivers have a steep gradient and narrow channels near their source, carrying large angular material. Downstream, the gradient gentles, channels widen and deepen, and material transported is smaller and more rounded. Floodplains also become wider and flatter towards the river mouth as the channel capacity increases.

1. Water on the Land

4. What does the
examiner want you
to do?

5. The drainage basin

6. How does a river change from source to
mouth?
Gradient
Channel depth
speed
Channel width
With a partner answer the above question. Draw small sketches if you wish to help
you explain.
landforms

7. The long Profile of a River
Copy this
down onto
your A3 sheet
• Steep gradient
• shallow/narrow channel
• large/angular ‘bedload’ • wider/deeper channel
• gentle slope
• open floodplains
• ‘bedload’ is smaller and more rounded
• very wide and deep channel
• gentle slope
• flat and wide open floodplains
• most ‘bedload’ is carried in ‘suspension’

8. Exam question (2010)
5 (a) Study Figure 14 which shows a long profile and cross profiles of a typical river.
Figure 14
Describe how the cross profile changes
downstream (3).

9. A
B
Name diagrams A and B

10. Erosion!
Write down a definition of erosion:
Erosion is the wearing away of the
land
A river near to its source concentrates on erosion
and especially vertical erosion (downwards).

11. Erosion! Rivers in the middle
and lower course
concentrate on
‘lateral’ erosion,
widening the flood
plain.

12. Erosion

13. How is material transported downstream?

14. Deposition
Deposition is when a river drops any eroded material it
has been transporting
•Rivers will always deposit the heaviest bedload first
•The smaller the bedload the further it can be
transported.
WHY DO RIVERS SLOW AND DROP MATERIAL?
• The volume of water falls in the river
• The amount of eroded material in the water is increased
• The water is shallower (inside of a meander/bend)
• The river reaches its mouth

15. What does the
examiner want you
to do?

16. river disappears from
view hidden by this spur
of land
Upper Valley -
River Conwy
(near Mignant
Moor)
Landforms in the upper course created by erosion
V-shaped valleys and interlocking spurs
Rapids
Waterfalls

17. V shaped valleys and Interlocking spurs
• Verticle
Vertical erosion in
the upper course
creates a V-shaped
valley. This is a steep
sided and narrow
valley.
Soil and loose rock
are moved down
hill by slope-wash
and soil-creep
The river winds its way
around interlocking spurs
of hard rock (not
meanders)
Steep valley gradient and no
flat valley floor. The channel
is narrow and shallow. Large
angular rocks are found as the
river has not has time to grind
them down by attrition and
abrasion.
Velocity is high
at rapids and
water falls but
slower else
where as the
river has to
overcome
friction
Add notes to
diagram

18. Interlocking
spurs
Shallow and
narrow river
channel

19. Waterfall formation

21. 5(a)(i) Symbol for steep slope / cliff present;
contours close together; 100m
contour down to 60m clear, but then sequence
stops.
2 x 1= 2 marks
Y

22. Erosion occurs where the flow is
fastest – on the outside of the bend

23. Deposition occurs where the flow is
slowest – on the inside of the bend

24. Erosion creates a river cliff on the
outside of the bend

25. Deposition creates a slip-off slope on
the inside of the bend
River Tees
meanders

26. Ox-bow lakes
BBC clip

27. Formation of levees
Watch the animation

28. Floodplains
The river's floodplain is the
wide, flat area of land
surrounding the river. The
floodplain is shaped as
meanders cut their way
through by lateral erosion
and deposition of material on
the inner bend of a meander
and at times of flood builds
up the valley floor.
The floodplain is formed by both erosion and deposition.

29. During flooding, as a river spills
onto the surrounding land, there is
a reduction in the velocity of the
water due to an increase in friction
between the water and the
floodplain.
This results in a loss of energy which causes deposition of the
large quantities of suspended sediment that a river carries as it
enters its lower course.
Floodplains

30. What does the
examiner want you
to do?

31. river
evapotranspiration
precipitation
water table
interception
percolation
infiltration
The drainage basin Remember…

32. What does a hydrograph look like?
Label your
hydrograph
with the
following
sentences.

33. What do hydrographs look like?
Flashy Subdued
What do you think the differences are between
the hydrographs?

34. Interpretation of Storm
Hydrographs
•Rainfall Intensity
•Rising Limb
•Recession Limb
•Lag time
•Peak flow compared to Base flow
•Recovery rate, back to Base flow
You need to refer to:
Basin lag time
0 12 24 36 48 30 72
Hours from start of rain storm
3
2
1
Discharge(m3/s)
Base flow
Through flow
Overland
flow
mm
4
3
2
Peak flow

35. What does the
examiner want you
to do?

38. After this time, there is little mention of major
floods until relatively recently, when they have
regularly made the headlines. Since 1998, floods have
been an almost annual occurrence.

39. Other flood events in the UK

40. Morpeth floods 2008
In early September the River
Wansbeck, which flows through the
town centre, could take no more after a
wet summer, & a particularly wet
August was followed by more than the
whole of September's rain falling within
48 hours. The heavy, persistent rain
came from an active area of low
pressure, which spent the weekend
over north-east England, moving only a
little.
Morpeth, Northumberland 2008

41. Yorkshire Floods in 2007
The summer floods of 2007 affecting
south & east Yorkshire
A prolonged period of wet weather,
much higher than average rainfall, &
concentrated periods of heavy rainfall,
all of which precipitated the very
serious local flood events. A year later,
many of the affected households had
still not fully recovered.

42. What does the
examiner want you
to do?

43. Your Case Study for a flood
in the rich world:-
Boscastle UK 2004

45. For this case study you will
need to know the following:-
(Same case study as Weather!)
• Where is Boscastle located?
• What caused the flash flood?
• What were the social effects?
• What were the economic effects?
• What were the environmental effects?
• What was the response?
• How is the flood risk being reduced for
the future?

47. Your Case Study for a FLOOD in
the poor world:-
Bangladesh,
2004

48. For this case study you will
need to know the following:-
• Where is Bangladesh located?
• What caused the flood?
• What were the social effects?
• What were the economic effects?
• What were the environmental effects?
• What was the response?
• How is the flood risk being reduced for
the future?

49. What does the
examiner want you
to do?

50. Turn to the front of your exercise book. Write the following:-
• In my end of unit test for Japan, I achieved a Level _____.
• I think the effort I put ino this topic was Excellent/Very
Good/Satisfactory/Poor.
• The thing I enjoyed the most about this topic was……
• In order to improve in my new topic (Volcanoes and
Earthquakes) I will………

51. Flood Control:
Should hard or soft engineering be used?
This comes under the heading of river basin
management – planning ahead and controlling change.
Hundreds of millions of people throughout the world
live close to rivers. Management methods are needed
to try to reduce the risks from flooding.

52. Key definitions:
Hard engineering:
The use of technology to control rivers, often
involving large and expensive projects.
Soft engineering:
Trying to work within the limits of the natural river
system. No permanent structures are built.
Multi-purpose project:
A large scale idea with more than one aim. Many water
projects aim to control floods and water supply

53. Decide whether each of these flood control methods is
an example of hard or soft engineering
Dams
Land use zoning Raise levees
Warnings
Preparation
Plant trees
Flood walls
Straighten river

54. Positives and negatives of hard engineering
Immediate results
Greatest protection
in the short and
medium term
Huge control
over the river
Large projects could
help to improve water
supply, provide HEP,
or leisure activities
Expensive to build
Require costly
maintenance
Could make
problems worse
in the future
Could create
unforeseen
problems
Where there is high social,
economic and political need
their use is not optional

55. Soft Engineering
How do these methods help to reduce the risk of flooding?
Land use zoning
WarningsPreparation
Plant trees
...or do nothing!!

56. What does the
examiner want you
to do?

57. Key Words
Water Surplus – Areas that have more water
than is needed – often such areas receive a high
rainfall total, but have a relatively small
population.
Water Deficit – Areas that have locations where the
rain that falls does not provide enough water on a
permanent basis. Shortages may occur under certain
conditions. E.g long periods without rain.
Water Stress – This occurs when the amount of water available does not
meet that required. This may be due to an inadequate supply at a particular
time or it may relate to water quality.

58. Study the information about flood control on the River Tees
Cow Green Reservoir Yarm defences Tidal Mouth
a) Fill in the table identifying the hard and soft
engineering strategies that are used.
b) Which one dominates – hard or soft? Explain why.

59. Why has demand for water
increased in the UK?
• The population has increased and is expected to increase
by around 10 million over the next 20 years. This means
more water used for washing/drinking etc.
• A more affluent lifestyle. People are buying more time
saving goods like washing machines and dishwashers that
take up more water.
•We demand foodstuffs out of season which contributes to
an increase in overall use of water.
• Electricity Power Stations use water for cooling.
• Demand for electricity in offices, industries and homes,
and for transport.

60. • Taking showers instead of baths
• Running water machines and dishwashers only
when full.
• Using hosepipes less
•Install water metres into our homes! Metres
would be used to charge people for the exact
volume of water they use. People with water
metres are likely to be careful with the amount of
water they use – they’re paying for every drop.
•Houses designed with better water efficiency
•Rainwater can be collected.

61. Case Study: a dam and reservoir
Kielder Water, Northumberland
Planned in the late
1960s to satisfy an
increase in demand
for water from the
then growing
chemical and steel
industries on
Teesside.
Opened in 1982.

62. Why this location?
Characteristic of the site Benefit of this
A valley with a wide floor
and steep sloping sides
High annual precipitation
(1370mm)
Very sparse human
population
Poor quality farmland far
from the markets
Rough grazing and
coniferous woodlands

63. Draw a sketch
map to show how
rivers are used
for water
transfers from
Kielder Water

64. The Benefits
North East England
enjoys the most reliable
water supply in England
Even in the driest
summers (e.g. 1995)
restrictions on water use
are unknown in the region
A pipeline has been
constructed to supply
water for use in York
Over 250,000 visitors are
attracted by outdoor
activities each year
Kielder Forest, surrounding
the reservoir, is the largest
woodland in England
Jobs in the water industry,
tourism and forestry exist
where there was only
previously farming
Biological studies have
shown no adverse
effects on wildlife in
connected river systems