state two advantages of constructing large dams on river for the generation of electricity. also mention two problem associated with these dams
Answers
Advantages :
*Pick any two you like :) *
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.
4. The lake that forms behind the dam can be used for water sports and leisure / pleasure activities. Often large dams become tourist attractions in their own right.
5. The lake's water can be used for irrigation purposes.
6. The build up of water in the lake means that energy can be stored until needed, when the water is released to produce electricity.
7. When in use, electricity produced by dam systems do not produce green house gases. They do not pollute the atmosphere.
Disadvantages / "Two problems" :
*Pick any 2 you like :) *
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.
4. People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcibly removed so that hydro-power schemes can go ahead.
5. The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earth quakes and has depressed the earths surface at its location.
6. Although modern planning and design of dams is good, in the past old dams have been known to be breached (the dam gives under the weight of water in the lake). This has led to deaths and flooding.
7. Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighbouring countries.
8. Building a large dam alters the natural water table level. For example, the building of the Aswan Dam in Egypt has altered the level of the water table. This is slowly leading to damage of many of its ancient monuments as salts and destructive minerals are deposited in the stone work from rising damp caused by the changing water table level.
Explanation:
Advantages of Dams
Advantages of dams are numerous, that is the reason so much money and work goes into building and maintaining them. Some of the advantages are:
Electricity is produced at the constant rate with the help of hydroelectricity or hydroelectric power.
If there is no need for electricity, then the sluice gates can also be closed or stopping the generation of electricity. Water can also be saved for the use of another time as and when the demand for electricity is high hence the usage of water remains judicious.
Dams are so designed by well-qualified engineers to span many of the decades and also can contribute to the generation of electricity for about many years or even decades to come.
The lake or reservoir which forms behind the dam can also be used for the irrigation purpose, water sports or even as other forms of pleasurable activities.Few large dams such as the Bhakra Nangal dam present in India is the tourist attractions.
The buildup of water inside lake means that the energy can also be stored when needed and also when water is released for producing the electricity.
When used, the produced electricity by the dams does not even produce the greenhouse gases and also hence they do not pollute the atmosphere.