What is a dam? Write two main advantages and two ill-effects of constructing big dam.
Dams are constructed across the rivers to regulate the flow of water and store the huge amounts of water in large reservoirs. This ensures the supply of water for irrigation and other purposes. Advantages of Dams: Ensures water availability for irrigation of fields. Water can be used to generate electricity in Hydel power stations by using turbines. Disadvantages of dams: Social problems: Human settlements get submerged under water. Environmental problems: Large scale loss of biodiversity and deforestation. Economic problems: Huge amount of public money utilised in their construction but benefits are not proportionate.
