Water management Flashcards
Uses of dams
Domestic and industrial use in urban, irrigation, Hydroelectric power, control/lessen floods, recreation
Impact of dams
Communities displaced to build dams, less water for those downstream meaning crop production is reduced, species are lost and ecosystems are damaged and there is flooding if the wall breaks
How does land use practices affect water?
Pollution of water, infrastructure prevents infiltration and increases run-off, alien vegetation uses more water than indigenous plants, soil erosion results in silt building up in dams which reduces the capacity of them
How does human activities affect water?
Water pollution from AMD (Acid Mine Drainage), Agricultural pollution from fertilizers, Industrial pollution creates dangerous chemicals and a raised salinity level
How does climate change affect water?
Decreased rainfall, Decreased dry spells mean more floods
What does sanitation mean?
Safe disposal of sewage and refuse
What is FBW?
Free Basic Water, it means every household is supposed to get 6000 liters of potable water per month for free.
What is the Orange river project?
Water from the Gariep Dam goes to the Sunday River and then the Fish River via tunnels and canals. This provides irrigation and HEP. It also helps control flooding.
What is the Tugela-Vaal scheme?
Provides water to the Vaal Dam to increase water for households and industries in the PWV area. Also used for irrigation. At night it is pumped uphill through the Drakensberg to the Driekloof and Sterkfontein dams where it will flow back down to generate electricity
What is the Berg river project?
Water from the Theewaterskloof Dam in the Sonderend River is transferred to the Berg River and the Eerste River. It captures winter rain and stores it for the summer
What is the Lesotho Highlands water project?
Largest water transfer scheme in Africa. Transfers water from Lesotho and Gauteng through dams and tunnels. It supplies water and is used tp generate HEP
What are the roles of the different municipalities?
National government: Creates water resource management policies and plan inter-basin transfers
Water boards: Operate dams, supply water to municipalities
Municipalities: Provide water to sanitation services, sell water to places like household, businesses and factories
Role of government: Research
Research alternative water supplies (desalination)
Role of government: Recycle water
From power stations and mines (purification plants)
Role of government: Enforce laws
To prevent pollution
Role of government: Wetlands
Wetlands reduce erosion, encourage wildlife, store water
Role of government: Alien vegetation
Need to be removed because they use large amounts of water (creates jobs)
What is a tributary?
A small river that joins a larger river
Physical causes for flooding
High rainfall, melting snow + icebergs, earthquakes, strong onshore winds and high tides
Human causes for flooding
Deforestation, poor farming practices and poor water management, debris floating in the water blocks the water, infrastructure
What is a hydrograph?
A graph that shows the change in discharge of river over time. It is measured in m³/second or cumecs
What flood risk management?
The assessment of the risks associated with flooding and then making use of the information to take appropriate measures such as: Constructing flood defenses, creating flood warning systems, developing policies to reduce development in area likely to flood
Why do floods do so much damage in informal settlements?
These areas often lack infrastructure like drains and storm water channels. They are sometimes flat so water doesn’t drain. To protect their homes residents can raise their homes and make furrows and storm water channels
What is done in rural and urban areas to prevent floods?
Preventing urban development, building storm water channels and keeping them clear litter and plants, maintaining wetlands, building early warning systems
