Water and Carbon Cycles- Changes to Water Cycle

Question 1

Physical factors which cause changes to the water cycle over time

Answer 1

• extreme weather events
• drought
• precipitation levels
• presence of vegetation
• evaporation rates
• soil properties
• topography
• desertification

Question 2

Human factors which cause changes to the water cycle over time

Answer 2

• deforestation
• afforestation
• urbanisation
• farming
• waster abstraction

Question 3

Explain the impact that deforestation has on the water cycle

Answer 3

• results in a complex set of changes to streams of all sizes
• now vegetation has fewer leaves and shallower roots- less water evapotranspired so more travels as run off
• amount of change depends on local conditions eg. topography, precipitation levels and land use after deforestation

Question 4

Explain the impact that agricultural soil drainage has on the water cycle

Answer 4

• a large depression in the water table is created
• in cities such as London there is a worry that increasing the ground water level will put the London Underground at risk

Question 5

Explain the impact El Niños have on the water cycle

Answer 5

• strong el niños are associated with above average precipitation in the Southern Hemisphere
• record rainfall often hits Peru, Chile and Ecuador