Rivers (Water on Land)


HideShow resource information
1. What is a rivers course?
The path of a river as it flows downhill.
1 of 76
2. What does the shape of the river valley and channel depend on?
The amount of erosion or depostition that is happening.
2 of 76
3. What does the long profile show?
The gradient (steepness) changes over the different courses.
3 of 76
4. What the cross profile show?
The cross section of the river.
4 of 76
5. Describe the upper course.
Steep, v shaped valley, steep sides, narrow, shallow channel.
5 of 76
6. Describe the middle course.
Medium gradient, gently sloping valley, wider, deeper channel.
6 of 76
7. Descrbe the lower course.
Gentle gradient, Very wide, almost flat valley, very wide and deep.
7 of 76
8. What is vertical erosion?
This deepends the river valley (and channel), making it V-Shaped. It's dominant in the upper course of the river.
8 of 76
9. What lateral erosion?
This widens the river valley (and channel). It's dominant in the middle and lower course.
9 of 76
10. What are the four processes of erosion?
Hydraulic action, abrasion, attrition, solution.
10 of 76
11. What is hydraulic action?
The force of the water breaks rock particles away from the river channel.
11 of 76
12. What is abrasion?
Eroded rocks picked up by the river scrape and rub against the channel, wearing it away. Most erosion happens like this.
12 of 76
13. What is attrition?
Eroded rocks picked up by the river smash into one another and break into smaller rocks. Their edges also get rounded off as they rub against eachother.
13 of 76
14. What is solution?
River water dissolves some types of rock like limestone or chalk.
14 of 76
15. What are the four processes of transportation?
Traction, saltation, suspension and solution.
15 of 76
16. What is traction?
Large particles like boulders are pushed along the river bed by the force of the water.
16 of 76
17. What is saltation?
Pebble-sized particles are bounced along the river bed by the force of the water.
17 of 76
18. What is suspension?
Small particles like silt and clay are carried along by the water.
18 of 76
19. What is solution?
Soluble materials dissolve in the water and are carried along.
19 of 76
20. What is deposition?
A river drops the eroded material is transporting
20 of 76
21. When does deposition occur?
When the river looses velocity (speed).
21 of 76
22. Why do rivers slow down?
1. Volume of water falls. 2. Amount of eroded material in the river increases. 3. The water is shallower eg on the inside of a bend. 4. The river reaches its mouth.
22 of 76
23. What are meanders?
Large bends in the river.
23 of 76
24. How are meanders formed?
The current is faster on the outside of the bend because the water river channel is deeper .(less friction) So erosion on outside of bend (river cliffs). Current slower on inside of bend. (more friction). Eroded material deposited inside of bend.
24 of 76
25. How are ox-bow lakes formed?
Meanders get larger over time. Erosion causes outside of bend to get closer. Only a bit of land left between bends. River breaks through this land usually during a flood. River flows shortest course. Depostion cuts of meander. Forming an oxbow lake.
25 of 76
26. Where do waterfalls form?
Where river flows over an area of hard rock followed by an area of softer rock.
26 of 76
27. How are waterfalls formed?
The softer rock is eroded more than the hard rock, creating a step in the river. This gets eroded more and more (the softer rock). A steep drop is created which is a waterfall.
27 of 76
28. Explain this further to make a plunge pool.
The hard rock is undercut by erosion. It becomes unsupported and collapses.The collapsed rocks are swirled around at the foot of the waterfall where they erode softer rock by abrasion. This creates a ddeep lunge pool.
28 of 76
29. Explain this further to explain how gorges are formed.
More undercutting causes more collapses. The waterfall will retreat moving back up the channel, leaving behind a steep sided gorge.
29 of 76
30. Describe and explain what happens on a flood plain.
Wide valley floor on either side of river. When a river floods onto the flood plain the water slows down and deposit eroded material. This builds up the flood plain. Meanders migrate across plain making it wider. Depostion occurs on slip off slopes.
30 of 76
31. What are levees and how are they formed?
Natural embankments on the edge of the river channel. During a flood eroded material is deposited. Heaviest material deposited first when river slows down. Over time deposited material builds up.
31 of 76
32. What are contour lines?
Orange lines all over the map. Tell you about height of the land by the numbers marked on them. They also tell you the steepess of the land by how close together the lines are.
32 of 76
33. Where do rivers flow? (contour lines)
From higher contour lines to lower ones.
33 of 76
34. What is the evidence for a waterfall on a map?
Symbol of a cliff (black, blocky lines) and the close contour lines.
34 of 76
35. What is the evidence for a upper course river on a map?
Nearby land is high, river crosses lots of contour lines in a short distance, narrow blue thin line. Contour lines very closs together and narrow. (V Shaped Valley).
35 of 76
36. What is the evidence for a lower course river on a map?
Nearby land low (less than 20m), river only crosses one contour line, joining a river or lake, wide (thick blue line), meanders, flood plain.
36 of 76
37. What is river discharge?
The volume of water that flows in a river per second. Measured in cumecs - cubic metres per second.
37 of 76
38. What do hydrographs show?
How the discharge at a certain point in a river changes over time.
38 of 76
39. What do storm hydrographs show?
The changes in river discharge around the time of a storm.
39 of 76
40. What is peak discharge, lag time, rising limb and falling limb?
Peak discharge - highest discharge in that time. Lag time - delay peak rainfall and peak discharge. Rising limb - Increase in river discharge as rainwater flows into the river. Falling limb - decrease in water discharge as river returns to norm.
40 of 76
41. Why does lag time happen?
Rain water doesnt directly fall into river channel. Delay as water running to channel.
41 of 76
42. How does the rainfall get to the river?
Surface runoff - overland. Infiltration - soaking into the ground and flowing slowly underground.
42 of 76
43. How does the amount and type of rainfall affect discharge?
Lots of rain and short heavy periods more runoff. Lag time decreased so discharge increased.
43 of 76
44. How does temperature affect discharge?
Hot + dry and cold + freezing condition create hard ground. Increases runoff. Lag time decreased, discharge increased.
44 of 76
45. How does previous weather conditions affect discharge?
If after lots of rain - ground saturated. No more water able to infiltrate. All water runsoff . Lag time decreased, discharge increased.
45 of 76
46. How does rock type affect discharge?
Water infiltrate through spores in permeable rocks and flows along cracks in pervious rocks - little run-off. Lag time increased, discharge decreased. Cannot infiltrate through, lots of runoff. Lag time decreased, discharge decreased.
46 of 76
47. How does land use affect discharge?
Urban have drainage systems and they're covered with impermeable materials like concrete. Increased runoff. Lag time decreased - discharge increased.
47 of 76
48. How does relief of the land affect discharge?
Lots of runoff on steep slopes. Lag time decreased - discharge increased.
48 of 76
49. What factors increase flooding?
Prolonged rainfall, heavy rainfall, snowmelt and relief.
49 of 76
50. How does prolonged rainfall increase flooding?
After long period of rain, ground saturated. No more water can infiltrate. Surface run off. Dishrge increases suddenly.
50 of 76
51. How does heavy rainfall increase flooding?
Alot more run-off. Increase discharge quickly.
51 of 76
52. How does snowmelt increase flooding?
A lot of water in a short space of time. Discharge increases quickly.
52 of 76
53. How does relief increase flooding?
Steep-sided valley - reach river channel quickly. Increase discharge quickly.
53 of 76
54. Which human factors increase flooding?
Deforestation and builing construction.
54 of 76
55. How does deforestation increase flooding?
Trees intercept water on their leaves, which then evaporates. Trees also take up water from the ground and store it. Cutting down trees increases the volume of water that reaches the river channel. Increases discharge.
55 of 76
56. How does building construction increase flooding?
Made from impermeable materials, and roads are made of concrete - also impermeable. Impermeable surfaces increase runoff and drains quickly take runoff to rivers. Increase discharge quickly.
56 of 76
57. Flooding in the UK appears to be happening .......... often.
More - more frequent over the past 20 years.
57 of 76
58. What is hard engineering?
Man made structures built to control the flow of rivers and reduce floodings.
58 of 76
59. What is soft engineering?
Schemes set up using knowledge of the river and its processes to reduce the effects of flooding.
59 of 76
60. Give some examples of hard and soft engineering.
Hard - Dams/reservoirs and channel straightening. Soft - flood warnings, preparation, flood plain zoning and 'do nothing'.
60 of 76
61. What is, the benefits and disadvantages of Dams and Reservoirs?
Dams are large walls that are built across rivers and a reservoir is behind the dam. B) Store water and can be used for drinking or creating hydroelectric power. D) Very expensive, flood existing settlements, material deposited (less fertile land)
61 of 76
62. What it is, benefits and disadvantages of Channel Straightening?
Rivers course straightened, and meanders cut out. B) Water moves more quickly, doesnt travel as far. D) Flooding may happen down stream as carried there faster. More erosion downstream - water flowing faster.
62 of 76
63. What it is, benefits and disadvantages of Flood Warnings?
Environment agency warms people on radio and TV. B) Impact reduced, give people time to move upstairs/evacuate, put sandbags in position. D) Dont stop flood. Difficult to get insurance. May not hear/ have access to them.
63 of 76
64. What is it, benefits and disadvantages of Preparation?
Reduce amount of damage caused. Make plans what to do in a flood - keep documents, torches and blankets in a handy place. D) Doesnt guarantee safety from flood. False sense of security. Expensive.
64 of 76
65. What is it, benefits and disadvantages of flood plain zoning?
Restrictions preventing buildings on parts of flood plains. B) Risk reduced - impermable surfaces not made. Impacts reduced - no buildings to be damaged. D) Expansion of urban areas limited. No help if area already built on.
65 of 76
66. What is it, benefits and disadvantages of 'Do Nothing'?
No money is spent on new engineering methods or existing ones. Flooding is a natural process accept the risks. B) The river floods, deposting material making land more fertile. D) Risk and impact not reduced. Cause alot of damage.
66 of 76
67. The north and west of the UK have ............... rainfall. Which means they have a ................. supply of water.
High - Good.
67 of 76
68. The south east and midlands have .............................population densities. Which means that there is a ..................... demand for water.
High and High.
68 of 76
69. The south east and midlands are areas of water ................... (Theres a greater demand than supply).
69 of 76
70. The north and west are areas of water .......... (theres a greater supply than demand).
70 of 76
71. Give some statistics to show the demand for water in the UK is increasing.
Past 25 years, amount of water used by people gone up by 50%. UK population due to rise by 10 million in next 20 years.
71 of 76
72. Give one way to deal with the supply and demand problem.
Transfer water from one area of surplus to an area of deficit.
72 of 76
73. Give some issues that water transfer can have.
Dams and aqueducts are expensive. Affect the wildlife that live in the rivers (fish migration disrupted). Political issues (not wanting to give water to another country).
73 of 76
74. What is another way to increase water supplies in dificit areas?
Build more reservoirs to store more water. (Can involve flooding settlements and relocating people).
74 of 76
75. What does fixing leaking pipes do? What happens in London everyday?
Fixing pipes would mean less water lost in transfer. Millions of litres of water lost everyday through leaky pipes in London.
75 of 76
76. How can we reduce the demand for water?
People reduce amount of water they use at home. Water companies want people to install water meters. Meters are used to charge people for the exact volume of water they use. People are careful with the amount of water they use.
76 of 76

Other cards in this set

Card 2


2. What does the shape of the river valley and channel depend on?


The amount of erosion or depostition that is happening.

Card 3


3. What does the long profile show?


Preview of the front of card 3

Card 4


4. What the cross profile show?


Preview of the front of card 4

Card 5


5. Describe the upper course.


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Water and rivers resources »