2. What is a dam?• A barrier built across a river to create a lake or for generation hydroelectricity.
3. Why are dams useful?• As a result water is stored in a lake that will form upstream of dam. The main purpose of the most of the dams is to create a reservoir of water to use at a later time. There are different types of dams like concrete dams, arch dams and earth dams. The design and construction of a dam depends upon its purpose and location as well as materials and workforce available. Dams are extremely useful to us for they help to control floods and supply water to dams and cities. Dams also generate hydroelectric power, and the water stored in the lake is useful for irrigation of crops. The lake that forms behind the dam can be useful for water sports and leisure activities. Often, large dams become tourist attractions of their own sight.
4. How should a dam be?• A dam must be waterlight, and must be also stable. The dam wall must have sufficient strength to firstly bear its own weight and secondly to resist the water pressure in the lake upstream of the dam. It must have an outlet valve to release water in controlled amounts as required. It also needs a spillway so that large volumes of flood water can flow around it without causing any damage to the structure itself.
5. The places we have dams in India
6. India in the world of dams• After independence we have made lots of progress in Dam and Water Reservoirs, Now India is one of the world’s most prolific dam-builders. Around 4300 large dams already constructed and many more in the pipeline, Almost half of which are more than twenty years old. These dams are major attraction of tourists from all over India. Some facts about the Indian dams are that The Tehri Dam is the eighth highest dam in the world. The Idukki dam is the first Indian arch dam in Periyar River Kerala is the largest arch dam in Asia. The Grand Anicut, Kallanai, located on Holy Kaveri River in Tamil Nadu, is the oldest dam in the world. Indira Sagar Dam is the Largest Reservoir in India. These dams with the channel provides an ideal environment for wildlife.
7. 5 biggest dams in India.
8. • 1. Tehri Dam: Tehri Dam located on the Bhagirathi River, Uttaranchal now become Uttarakhand. Tehri Dam is the highest dam in India, With a height of 261 meters and the eighth tallest dam in the world. Tehri Dam
9. • 2. Bhakra Nangal Dam: Bhakra Nangal Dam is a gravity dam across the sutlej river Himachal Pradesh. Bhakra Nangal is the largest gravity dam in India, with a height of 225 meters. Its reservoir, known as the “Gobind Sagar Lake” it is the second largest reservoir in India, the first being Indira Sagar dam. Bhakra Nangal Dam
10. • 3. Hirakud Dam: Hirakud dam built across the Mahanadi River in Orissa. Hirakud Dam is one of the longest dams in the world about 26 km in length. There are two observation towers on the dam one is “Gandhi Minar” and another one is “Nehru Minar”. Hirakud Dam
11. • 4. Nagarjunasagar Dam: Nagarjuna Sagar Dam is the world’s largest masonry dam with a height of 124 meters, built across Krishna River in Andhra Pradesh. Nagarjuna Sagar Dam is certainly the pride of India- considered the largest man-made lake in the world. Nagarjunasagar Dam
12. • 5. Sardar Sarovar Dam: Sardar Sarovar Dam also known as “Narmada Dam” is the largest dam to be built, with a height of 138 meters, over the Sacred Narmada River in Gujarat. Drought prone areas of Kutch and Saurashtra will get irrigate by this project. The Narmada dam is India’s most controversial dam project. Sardar Sarovar Dam
13. Thank you for watching my presentation. Hope you like it.