explain how dams can cause floods? give instances where floods have occurred due to dams.
Answers
Answer:
ITS NOT THE DAM WHICH CAUSES FLOODS ITS THE INCREASE OF WATER LEVEL WHICH CAUSES FLOODS.
Answer:
But due to heavy rain the water level rises above HFL then need to discharge the water by opening flood gates provided in dam along with spillways overflow and it cause heavy flow of water and sinkage of near by areas causing flood.Stagnant reservoir pools disorient migrating fish and can significantly increase the duration of their migration. Dams can also alter the timing of flows. Some hydropower dams, for example, withhold and then release water to generate power for peak demand periods.Some environmental problems caused by dams are as follow:
(i) Soil Erosion
(ii) Species Extinction
(iii) Spread of Disease
(iv) Changes to Earth's Rotation
(v) Sedimentation
(vi) Siltation
(vi) Water logging
(viii) Salinisation