Def. Water Surplus
A situation in which the usable water supply exceeds the demand
Def. Water Deficit
A situation in which the usable water supply does not satisfy the demand
Def. Physical Water Scarcity
The natural reasons for low water supply i.e. low rainfall. Deserts, such as those in the middle East are obvious examples of physical water scarcity
Def. Economic Water Scarcity
The human reasons for low water supply i.e. lack of plumbing infrastructure.
What are the causes of water scarcity linked to growth in demand?
What are the causes of water scarcity linked to falling supply?
Def. Appropriate Technology
Equipment that the local community is able to use relatively easily and without much cost.
Aka intermediate technology
Name examples of appropriate technology
What are PlayPumps and how do they work?
Children run around, playing on it’s merry-go-round structure, pumping water into a container
How much water do PlayPumps pump in one hour?
1400 Litres
What are the advantages and disadvantages of playpumps?
What are the advantages and disadvantages of solar-powered bore-holes
How many people live without direct access to water?
750 million
What proportion of the worlds population has no toilets?
1/3
What are the impacts of water scarcity?
What are wells and boreholes, and how do they work?
Water soaks down through soils and rocks to collect underground.
People then extract the water by drilling boreholes or digging wells through the rock and water is brought up using buckets, pumps or pressure.
This source of water is also known as ground water.
What are aquifers?
Aquifers are naturally occurring stores of water found under the ground.
What are the advantages of drilling boreholes and wells?
What are the disadvantages of drilling boreholes and wells?
What are dams and reservoirs, and how do they work?
A dam is a large scale management scheme, an artificial structure that prevents the flow of water of a river. They are usually built in a valley with steep sides. Water builds up behind the dam, creating a reservoir.
Water can be stored in the reservoir in periods of surplus tp be used in periods of water deficit.
What are the advantages of dams and reservoirs?
What are the disadvantages of dams and reservoirs?
What is desalination, and how does it work?
The process at a desalination plant to separate salt from water, transforming saltwater to freshwater so it can be drank.
Using processes like Multi-stage flash distillation or reverse osmosis
What are the advantages of desalination?