Question

8) Why are dams often added to rivers? What are some of the negative consequences of this?

Answer 1

ANS. 8. Dams are often added to the river to store water for demand in the future for energy and water. Also, to increase the hydraulic head for the generation of electricity, agricultural purposes, industrial use, flood control, leisure purposes like boating, etc. It produces a renewable sources of energy.

Negative consequences -

• Blockage of rivers - Dams act as barriers and therefore they block rivers that prevent fishes and other aquatic organisms to migrate. This interferes with their spawning habitat, food resources and escapes predation.
• Slow Rivers - Some aquatic organisms depend on the steady flow of water to guide them. stagnant water disorient fish migration. irregularities because the flow of the river destroys the natural seasonal flow and hence affects natural growth.
• Alteration of habitat - Because of dams, entrapment of sediments and burying of riverbeds happens which affects the creation of natural habitat.
• Water quality - due to stagnation of water, heating-up of the rivers and streams negatively affects the temperature-sensitive species and can produce algal blooms in water that decreases the oxygen content of water.