Hydrological Cycle

Question 1

Impact of human activity on the hydrological cycle within a drainage basin

Answer 1

• Deforestation
• Irrigation
• Urbanisation
• Mining

Question 2

Deforestation

Answer 2

The cutting down of trees increases the potential for soil erosion which leads to less infiltration and therefore more surface run-off.
Soil can be washed into rivers which raises the river bed and can lead to flooding
Changes to vegetation cover can lead to more extreme river flows as water is not intercepted and stored by the trees

Question 3

Irrigation

Answer 3

Taking water from a river or ground water storage can reduce river flow
Lowering water tables and increasing evaporation by placing water in surface stores, e.g. ditches/channels

Question 4

Urbanisation

Answer 4

The removal of natural vegetation and replacement with impermeable concrete/hard surfaces and drains can speed up surface run-off and can lead to higher river levels.