Question

what would have happened if rivers dry

Answer 1

That would be end of the river and end of all living beings. Because what is river..it is water which keeps on flowing. And we all know that without water life is no more..

Answer 2

if rivers dry, following impacts may occur:
1.shortage of production 
2.SCARCITY OF WATER LEADS TO SEVERAL DISEASES.
3.the life of living beings might be harder 
4.people migrate to other places.
5.trees will become dry
6.all the areas become deserted.
7.ground water level could not be improved
8.in the summer, people will not get drinking water
9.this may further lead to drought
10.people will not be able to wash their clothes and do domesticated works.