Give scientific reasons for the following statements :
Though hydropower is renewable source of energy, it creates certain problems.

Explanation

Hydropower is renewable source of energy because water gets refilled in reservoir during raining.
`rarr` High-rise dams are constructed to generate hydroelectricity.
`rarr` Such dams are constructed in hilly areas causing environmental changes.
`rarr` Large eco-systems are submerged under water and destroyed.
`rarr` The submerged vegetation decaying anaerobically releases large amount of greenhouse gas, i.e., methane.
`rarr` Large areas of agricultural land is also submerged. Many natives are thus displaced.
`rarr` Rural-tribal human races may lose their habitat.
So, Hydropower plant construction creates certain problems.