water uses, demand & supply

Approx what percentage of earths water is accessible fresh water

~ 0.9%

How is water used in a developed vs emerging/developing country?

Developed

• mostly industry ( ~ 69%)

• Followed by agriculture (~ 30%)

• Then domestic ( ~ 11%)

Developing

• mostly agriculture ( ~82%)

• Followed by industrial ( ~ 10%)

• Then domestic ( ~ 8%)

Define demand for water

The amount of water required by users to meet their needs

Define supply of water

The amount of water available

Define water balance

The difference between supply and demand

Define water security

The needs of the population being met by an acceptable quantity and quality of water

Why has the demand for water increased - 6

• improving living standards

• Increased use of water in leisure and tourism

• Increased urbanisation

• Population growth

• Increasing industry

• Increasing use in agriculture

What are the 3 main sources where water supply comes from

• lakes and rivers

• Aquifers (naturally occurring store of water in rocks underground)

• Reservoirs

Define water deficit

Water shortages

What can cause water deficit

• low supply - lack of rain, high levels of evaporation or poor water management

• High demand - increasing population, industry and agriculture

Or most likely a combination of both

What is water surplus and what can cause it

Having more than enough water

• high supply - high precipitation, low evaporation rates, effective water management

• Low demand - low population, effective water management, low temperatures

Or most likely a combination of both

What does it mean if water is potable and why is this important

Potable - water that is safe to drink because it is free from bacteria and pollution

Unsafe water can result in death and disease

What are the main sources of pollution in the agriculture sector

• fertilisers, herbicides and pesticides dissolve in rain water

• Soil erosion

What are the main sources of pollution in the industry sector

• spillages of oil

• Water is used as a coolant and returned to rivers at high temps

• Toxic substances from industrial processes being releases into rivers

What are the main sources of pollution in the domestic sector

• Untreated sewage

• A water which has been used for washing clothes and bathing

• Water that has been treated with chlorine

What are the dams reservoirs used for

To collect and store water

How is water usually transported and how does this change depending on the development of the country

• water is usually transferred via pipelines

• Developed countries have a more extensive and effective pipeline infrastructure that developing due to high costs

Can sea water be used for drinking? What must be done to it? What countries use this process?

It can, through the process of desalination - where the salt water is removed

However, this is very expensive and uses lots of energy. This means mainly very wealthy countries with not a lot of rivers and alternative options have used this - such as Saudi Arabia and other countries in the Middle East.

What are the 3 main stage of water supply

Collection → treatment → delivery

Name 2 of the process that water goes through whilst being treated

Filtration and disinfection