Geography possible 20 marker

Question 1

What is Deforestation?

Answer 1

The large scale removal and cutting down of trees.

Question 2

How does deforestation impact the water cycle?

Answer 2

• There is an increased risk of flooding due to there being less interception from the trees and their roots.
• When forests are removed the new vegetation generally has shallower roots meaning it uses less water than the forest it replaces and therefore less water evaporates from the surface to be returned to the atmosphere.
• less infiltration means that there will be less evapotranspiration and therefore it is a positive feedback loop.

Question 3

What are examples of the impact of deforestation on the water cycle?

Answer 3

Tropical South America contains the world’s largest continuous tropical forest (the amazon).

Question 4

What is Soil Drainage?

Answer 4

Subsurface drainage removes excess water from the soil profile through a network of perforated tubes.

Question 5

How does soil drainage impact the water cycle?

Answer 5

• farmers drain soil to make land more productive and begin to add fertilisers which increases eutrophication and reduces the quality of the water.
• Artificially increasing throughflow increases the risk of flooding
• The discharge of rivers becomes more flashy peak discharges increase and flooding becomes more likely.

Question 6

What are examples of the impact of soil drainage on the water cycle?

Answer 6

Increased flooding in the North York Moors.

Question 7

What is Groundwater Abstraction?

Answer 7

Pumping underground water from an aquifer or groundwater source.

Question 8

How does groundwater abstraction impact the water cycle?

Answer 8

• Problems can occur when the demand for water exceeds the amount available during a certain period.
• sinking water tables make rivers less reliable.
• groundwater stores can become depleted and take a long time to fill back up.

Question 9

What are examples of groundwater abstraction on the water cycle?

Answer 9

• Water abstraction from the chalk of southern England
• London Aquifer

Question 10

What is irrigation?

Answer 10

• Providing waters to areas of land to promote crop growth

Question 11

What is the impact of irrigation on the water cycle?

Answer 11

• Water comes from local stores or aquifers
• Lowering river levels and groundwater stores might be reduced
• Water goes back into the ground so only has a small impact