human activities impact on the hydrological cycle*

Question 1

deforestation

Answer 1

increases the amount of run-off water and it decreases transpiration

As there are no longer tree roots to take up groundwater or leaves to intercept precipitation, this leads to more extreme river flows

Question 2

irrigation

Answer 2

Irrigation takes water from underground water stores therefore lowering the water table

It also places more water in surface stores, (i.e. canals/ditches), which will increase evaporation and transpiration

Question 3

urbanisation

Answer 3

removal of natural vegetation and replacement with impermeable surfaces and drains can speed up surface runoff and lead to higher river levels as there is less interception.

also decreases the amount of water which returns to groundwater storage, possibly reduce water table

Question 4

resivoirs/dams

Answer 4

interfering with the natural path of the water can change the cycle dramatically

means less water is going underground and being stored. More surface water means increased evaporation and cloud formation, which may ultimately affect rainfall patterns.

Question 5

mining

Answer 5

lakes, rivers and resivoirs ‘silt up’ leading to reduced storage capacity in these areas.

reduced vegetation cover which leads to increased runoff and lower transpiration