The correct answer is: All of the above.
Large dams have a number of negative impacts on the environment and people. They can displace communities, disrupt ecosystems, and impact downstream water flow.
Displacement of communities: Large dams often require the relocation of entire communities, which can have a devastating impact on their livelihoods and culture. In Manipur, for example, the construction of the Loktak Dam displaced over 100,000 people.
Environmental impacts: Large dams can have a number of negative impacts on the environment, including deforestation, soil erosion, and water pollution. They can also disrupt the natural flow of rivers, which can impact fish populations and other aquatic life.
Downstream water flow: Large dams can also impact downstream water flow, reducing the amount of water available for irrigation, drinking, and other uses. In Manipur, for example, the construction of the Loktak Dam has reduced the flow of water into the Manipur River, which has had a negative impact on agriculture and fisheries.
In conclusion, large dams have a number of negative impacts on the environment and people. They can displace communities, disrupt ecosystems, and impact downstream water flow.