The correct answer is: d) All of the above.
Pollution, dam construction, and sand mining are all major challenges to the health of rivers in Nagaland.
Pollution can come from a variety of sources, including industrial waste, sewage, and agricultural runoff. It can cause a number of problems for rivers, including:
- Depleting oxygen levels, which can kill fish and other aquatic life.
- Harming plants and animals that live in or near the river.
- Making the water unsafe for drinking, bathing, or fishing.
Dam construction can also have a negative impact on rivers. Dams can block the flow of water, which can disrupt the natural ecosystem of the river. They can also lead to the accumulation of sediment behind the dam, which can change the river’s course and make it more difficult for fish to migrate.
Sand mining is the process of extracting sand from riverbeds. This can also have a negative impact on rivers, as it can lead to erosion and the destruction of riverbanks. It can also disrupt the natural flow of the river and make it more difficult for fish to migrate.
All of these activities can have a serious impact on the health of rivers in Nagaland. It is important to take steps to protect these rivers and ensure that they remain healthy for future generations.