4.6 Multipurpose dam projects Flashcards
1
Q
factors affecting the choice of site of a dam-
7 points
A
- Rivers and lakes nearby to provide water
- The valley should be quite narrow, where the dam is built (wider dam would be more costly)
- A dam also needs to be quite high up a valley (Higher it is,the greater the pressure of water,will have more potential energy)
- Should be sited away from the developed areas to reduce the risk of getting pollution in the reservoir.
- High precipitation to provide sufficient water;
- Low temperature to prevent evaporation;
- Built on strong impermeable rock so water doesn’t drain and has a good foundation;
2
Q
advantages of a dam
9 points
A
- Generation of electricity in hydro-electric power plants;
- Flood control;
- Irrigation
- Creates recreational land for tourism and leisure
- Provision of water
- Creation of habitat for wetland species
- Renewable source of energy so Doesn’t produce greenhouse gases
- Reduces fossil fuel consumption
- Creates more jobs
3
Q
disadvantages of a dam
7 points
A
- Relocating people
- Flooding land
- Disrupting the lifecycles of fish and other aquatic organisms.
- Altering the water supply for people downstream of the dam.
- Reducing the enrichment of soil downstream of the dam.
- Dam may become redundant due to sediment build up
- expensive to build
4
Q
Sustainability of dams:
A
Alternative for burning of fossil fuels as no greenhouse gases are produced.
5
Q
Unsustainability of dams:
A
- Reservoir can become silted due to material carried into it by rivers;
- Dam structure under a lot of pressure can deteriorate and eventually fail;
- Have negative effects on the environment and fish population.