Summary. AGRICULTURE Major use of water as we struggle to meet food demands of a rising population Uses 69% of the world’s fresh water supply Some forms of agriculture are less water-efficient than others
To build up a Case study about the Aral Sea
To understand how man can have a negative impact upon an area by changing the water supply
To discover possible solutions to reverse the environmental disaster
Task:At the bottom of the same table classify the impacts of pollution using your previous table.Which category has the worst impact? Explain your answer
Causes a range of diseases such as cholera and dysentery etc.
Can poison stretches of river completely killing all life.
Leads to eutrophication (water is deprived of oxygen by rich nutrients).
Consumes oxygen in the water and kills many organisms.
Can lead to cancer.
High toxic – even at low concentrations – causes the death of most river life.
Increases the rate of decomposition of biodegradable waste, reducing the water’s ability to hold oxygen.
Affects the colour of the water and kills fish/shellfish.
The UK adds 1, 400 million litres of sewage daily into our rivers.
Sewage disposal in developing countries will causes 135 million deaths by 2020
Dams can collect sediments reducing soil fertility and prevent fish flows damaging ecosystems
Each year the world generates 400 billion tonnes of industrial waste.
Removing water from ground water sources can have unintended consequences on the environment.