How do people affect water supplies?Can you remember the case studies?

Unsustainable use of water- human impactAral Sea

• Central Asian Desert• Overabstraction of water for

growing cotton• Water levels reduced massively

and water that is left has become more saline

• Wetlands have been lost since they have dried up.

• Dust storms carry salt and chemicals causing an increase in diseases such as anaemia and TB.

River Danube• Germany+5others• Eu’s 2nd largest river system:85

mill ppl live along the river or its tributaries.

• Eutrophication- factories and agriculture.

• Household pollution• 1998-Danube protection

agreement

Large scale management-Colorado• Rocky mountains to the Gulf of California USA- 1450miles long• series of dams were constructed • - Hydro-Electric Power (HEP)

– Irrigation water for surrounding farmland – Water supply to the population – Flood control.

• Urban centres e.g. Las Vegas, San Diego, Phoenix and Los Angeles have all become dependent on the Colorado dam system for water and electricity.

• In Phoenix, rapid population growth as people see the desert environment being turned into a pleasant living environment.

• The water from the dam system allows trees to grow, swimming pools to be built and artificial lawns to be planted which can be watered by a mass of sprinklers dotted all over the city.

• Cities and habitats downstream do not get their “fair share” of the water since it is being held in Dams upstream. This leads to conflict between conservationists, who are worried about wetland environments declining because of a lack of water and other local people

• The reservoirs behind the dams can be used for tourism- swimming, sailing etc.

Intermediate Technology

• “Schemes that meet the needs of local people and the environment in which they live.”

• Tanzania- East Africa- Handpump• Very poor -life expectancy is 46!• Over 70% of the population has no access to safe drinking water.• 20% of infant deaths caused by Diarrhoea due to water contamination.• Water aid helped to construct intermediate technology- technology that is

simple to create, uses local materials that communities can access and is easily maintained. The charity also provides training for several local people, allowing them to maintain the pumps themselves.

• Afridev handpump• Easily maintained• One weeks training given to local people to teach them to fix the pumps.• Provides clean water and helps to eradicate water Bourne diseases.