human changes in the water cycle

Question 1

what are the human changes in the water cycle?

Answer 1

deforestation
water abstraction
farming practises

Question 2

define deforestation

Answer 2

process by which areas of forests are removed and converted into something else

Question 3

what impact does deforestation have on the water cycle?

Answer 3

new vegetation has fewer leaves and shallower roots which means it uses less water than the forest it replaced
less interception so water runs off the land increasing streamflow
less water evaporated

Question 4

suggest several points deforestation has had on climate/water cycle / land surface

Answer 4

-if deforestation does not cause decreased rainfall via atmospheric feedback discharge will likely be significantly increased

Question 5

what is soil drainage?

Answer 5

removes excess water from the soil profile. it is carried out usually through a network of perforated tubes installed 60-120 cm below the surface

Question 6

what is water abstraction?

Answer 6

the removal of freshwater from groundwater stores

Question 7

what are the problems with water abstraction

Answer 7

• water being pumped faster than its being replenished which results in sinking water tables
• salt-water from the sea degrades the groundwater

Question 8

how does soil drainage impact upon water cycle?

Answer 8

removes excess water from soil
reduces soil moisture
transfer of water is quicker
less groundwater and throughflow

Question 9

how does livestock impact upon water cylce?

Answer 9

reduce infiltration as compress the land

Question 10

how does irrigation impact upon the water cycle?

Answer 10

takes water from rivers and puts it on the land lowering river levels