Lesson 15 Flashcards
What is water security?
Ability to safeguard and maintain a sustainable and reliable source of safe ringing water for economic and social needs of a country and its natural environment without concern for pollution and water-related disasters
How can water surplus occur?
• Climates with regular, plentiful rainfall and low evaporation rates
• Lower water usage with water-efficient appliances
• Low population
• Effective treatment of used water
• Protection against pollution
Why is global water demand increasing?
• Increasing population
• Greater demand for food
• Improving technology and appliances which use more water
• More manufacturing of products which uses water
Describe difference between physical and economic water security
• Physical - When a country is water scarce due to environment, climate and natural conditions, causing less than 500mm of annual rainfall
• Economic - When country doesn’t have economic needs to effectively treat and protect supplies of water
What is water catchment?
• Collecting water from rainfall and storing it
What is diversion?
• Changing course of a river to take water to different area
• Moving water from area of surplus to area of deficit
What is storage transfer?
• Water can be stored during times of surplus and then used during deficit
• Dam over river can create reservoir
• Filled during period of rainfall and released during dryer conditions
What is desalination?
• Removing salts and minerals from saline water so it is potable
• Seawater is passed through a series of membranes to remove salt using reverse osmosis
What are cons of water catchment?
• Isn’t effective during dry seasons
• May not be effective for larger and denser populations
What are cons of diversion?
• Increased water stress in area where water is diverted from
• This could cause environmental and social damage to area
• Infrastructure is expensive to maintain
What are cons of storage transfer?
• Settlements may have to be drowned causing relocation
• Impacts environment negatively as drastic change in an environment
• Large scale projects can be very expensive and time-consuming
What are cons of desalination?
• Very expensive
• Less viable for landlocked countries
• Creates saline waste
What are pros of diversion?
• Improves water security in receiving area
• Reliable once infrastructure is established
What are pros of water catchment?
• Relatively cheap compared to other methods
• Can be done at any scale
What are pros of desalination?
• Good potential due to large amounts of sea water
• Reliable when plant is constructed
What are pros of storage transfer?
• Creates jobs in construction, energy and tourism
• Reduces flood risk
• Can be used to generate HEP
• Reservoir can also be used for fishing and leisure
Name example when diversion was used
• Rivers from Aral Sea in Kazakhstan and Uzbekistan diverted for crop irrigation
• Shrunk by 90%
• Fishing industry destroyed there
Name example where storage and transfer is used
• Kielder Water, Northumberland, UK
• Grand Ethiopian Renaissance Dam
Name example where desalination is used
Maldives and Israel
Name example where water catchment is used
• Effective enough in Gansu Province, China for irrigation of crops to meet needs of locals
• Used on roofs of houses and public building where they have storage tank up there
