How is coal related to hydropower?
There is no direct relation between coal and hydro power.
But if we make more hydro power we can reduce burning of coal.This will reduce atmospheric pollution and global warming.
Burning of coal is harmful for environment and it causes carbon di oxide to increase .Carbon di oxide is a green house gas which caused global warming.
COal also contains sulfur which release sulfur di oxide in air.that is reason for acid rain.