River landscapes + processes [Part 2] 🌊

Question 1

Explain two ways in which climate has an influence on river landscapes in the UK.

Hint: rainy climate, wetter climate + higher discharge, rate of erosion.

Answer 1

• one way in which climate has an influence on river landscapes in the UK, is chemical weathering.
• This is because, chemical weathering occurs more in places with a rainy climate.
• and Both carbonation + dissolution weathering can happen when rainwater comes into contact with minerals that make up rocks in river valley + this can affect the river landscape by making valleys less stable.
• rivers in wetter climates have a higher discharge + a higher discharge increases the rate of erosion [Because if a river has a high volume of water, its has more power to erode river bands and bed ———-> adds material to river’s load.

Question 2

What’s one way how temperature in the UK, can influence river processes ? [2]

Answer 2

• during winter, temperature can drop below freezing [especially at night], and this leads to freeze-thaw weathering.
• and because of weathering, mass movement suck as rockfalls becomes more likely- since it loosens material on the valley side,

Question 3

Explain two ways how storms can impact river processes [2]

Answer 3

• storms bring heavy rainfall, which causes the ground to become saturated and this makes it heavier and less stable.
• mass movement will then be more likely- (because river banks may slide or slump into river channel).
• ; floods caused by storms can also build up the floodplain, and form levees.

Question 4

Explain two ways in which droughts can impact river processes [2]

Answer 4

• mass movement more likely to take place because ground is dry.
• less erosion occurs because of lower discharge, which means the river has less energy and is less able or pick up and transport material.

Question 5

Explain two ways in which urbanisation can affect river processes and landscapes [2]

Answer 5

• the volume of water in the river rapidly increases because urban areas have lots of impermeable surfaces (e.g- concrete).
• and because water can’t infiltrate into these surfaces, more water flows quickly overland when it rains, gutters and drains will quickly take water runoff to rivers.
• this means the amount of transportation will also increase because, more rainwater gets into a river at a shorter time (in urban areas), therefore, the river has more energy,

Question 6

Explain two ways in which agriculture can affect river processes and landscapes [2]

Answer 6

• irrigation (supplying crops with water) can involve taking water from a river, which causes a reduction in the amount of water in a river, decreases a river’s ability to erode and transport material, so it may deposit material instead.
• ploughing of farmland exposed soil, which allows it to be washed away into rivers when it rains- gives rivers a large sediment load + leads to more deposition occurring downstream.

Question 7

Explain two how industry can affect river processes and landscapes [4]

Answer 7

• air pollution from factories + vehicles can make rainwater more acidic- this results in more chemical weathering of the river landscape.
• dredging- creates deeper channels which allow large boats to fit. However, it means the river has a faster flow + has more energy for erosion.

Question 8

What does river discharge mean?

Answer 8

• river discharge, is the volume of water that flows in a river per second

Question 9

Explain how prolonged rainfall can influence river flooding

Answer 9

• After a long period of rain, soil becomes saturated which means that any further rainfall cannot infiltrate the soil.
• This increases runoff into rivers, quickly increasing discharge- so flooding is more likely to happen.

Question 10

How can heavy rainfall influence river flooding?

Answer 10

• Heavy rainfall means that the water arrives too rapidly for infiltration- this means that there’s a lot of runoff.
• This them increases discharge quickly, which increases the risk of a flood [happening].

Question 11

Explain how geology can affect river flooding

Answer 11

• clay soil - some rocks (such as granite + shale are impermeable) so runoff is increased. When it rains, discharge quickly increases, which can cause a flood

Question 12

RECAP: What does the term ‘impermeable’ mean?

Answer 12

Impermeable means that infiltration is not allowed.

Question 13

What does the term ‘relief’ mean?

Answer 13

• relief, is the change in the height of the land.

Question 14

Explain how relief can influence river flooding.

Answer 14

• If a river is in a steep-sided valley, water reaches the river channel much faster, because water flows more quickly on steeper slopes.
• Discharge rapidly increases, which therefore increases the risk of a flood

Question 15

Explain how building (s) can cause river flooding. [2]

Answer 15

• Because buildings are often made from impermeable materials, + they’re surrounded by rocks made from tarmac, this increases runoff, and drains quickly take runoff to rivers.
• [discharge increases quickly, so there’s a greater risk of flooding].

Question 16

Explain how deforestation can cause river flooding [4].

Answer 16

• vegetation intercepts rainwater- (rainwater lands on plants, and is stored there before evaporating).

-

Question 17

Explain how deforestation can cause river flooding [4].

Answer 17

• vegetation intercepts rainwater- (rainwater lands on plants, and is stored there before evaporating).
• plants take up water from soil + allows more rainwater to infiltrate soil, instead of running over the surface.
• when vegetation is removed, there’s
  less interception + infiltration- this means more rainwater goes straight to streams + rivers by surface runoff.
• increases discharge + makes flooding more likely.

Question 18

Give two ways in which river flooding can affect people.

Answer 18

• people can be killed or injured by floodwater.
• people can be made homeless because their properties can become damaged.

Question 19

Give two ways in which river flooding can affect the environment

Answer 19

• Farmland can be ruined, because of deposited silt and sediment after a flood.
• floodwater contaminated with sewage + rubbish can pollute rivers- this damages wildlife habitats.

Question 20

What’s a second way how temperature in the UK, can influence river landscapes ?

Answer 20

• in summer, higher temperatures speed up rate of chemical reactions, so the rate of chemical weathering tends to increase.
• and because of weathering, mass movement suck as rockfalls becomes more likely- [since it loosens material on the valley side. ]