SCIENCE
EARTH SCIENCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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to prevent runoff
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to prevent flooding downstream
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to increase the flow of water in the river
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to decrease the amount of water upstream
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Detailed explanation-1: -During heavy rainfall, the dam stops the water from overflowing in the particular area. When the height of the dam is low, the gates of the dam opens up. So, the excess water flows into the area of livelihood. This causes flooding.
Detailed explanation-2: -Because dams trap sediment, they release relatively clear water that cuts deeper into the river’s bed. This incision creates a roomier channel that can carry more water and prevent floodwaters from spilling over riverbanks.
Detailed explanation-3: -The key purposes of dams are generally a combination of irrigation, hydropower, flood mitigation, and town water supply. Dams can supply water for irrigation to grow food and for farm animals to drink. Some dams generate electricity from hydropower, while others can be used to minimise the impact of flood events.
Detailed explanation-4: -One of the first problems with dams is the erosion of land. Dams hold back the sediment load normally found in a river flow, depriving the downstream of this. In order to make up for the sediments, the downstream water erodes its channels and banks. This lowering of the riverbed threatens vegetation and river wildlife.