What are dams? What are their advantages and disadvantages? [5 MARKS]
Definition: 2 Marks
Difference: 3 Marks
A dam is a barrier that impounds water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for such activities as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures are used to manage or prevent water flow into specific land regions
Advantages:
1) Once a dam is constructed, electricity can be produced at a constant rate.
2) If electricity is not needed, the sluice gates can be shut, stopping electricity generation. The water can be saved for use another time when electricity demand is high.
3) Dams are designed to last many decades and so can contribute to the generation of electricity for many years / decades.
Disadvantages:
1) Dams are extremely expensive to build and must be built to a very high standard.
2) The high cost of dam construction means that they must operate for many decades to become profitable.
3) The flooding of large areas of land means that the natural environment is destroyed