Huma Impacts On Water Availability?

Question 0

Chemical fertilisers

Answer 0

Used by farmers and can contaminate groundwater as well as rivers.
Sewage and fertilisers add nutrients to the water and increase the growth of algae down stream, the algae removes oxygen from the water, for example along the shores of the Gulf of Mexico.

Question 1

Sewage disposal

Answer 1

In developing countries it is expected to cause 135 million deaths by 2020. Diseases such as hepatitis, typhoid and cholera are common in areas of polluted water.

Question 2

Industrial waste

Answer 2

Each year the world creates 400 billion tonnes of industrial waste, much of which is pumped into oceans and rivers. Heavy metals such as lead also become concentrated in rivers.

Question 3

Dams

Answer 3

Trap sediment if reservoirs which reduces flood plain fertility and the flow of nutrients from rivers into seas. This may damage coastal fish stocks and prevent beach formation.

Question 4

Abstraction

Answer 4

Worldwide, water is being extracted from aquifers faster than it is being replaced. In arid areas, rainfall can never recharge these underground stores.
The removal of freshwater from aquifers in coastal locations can upset the natural balance of saline and fresh groundwater and lead to salt water incursion.