Question

if all land is paved with cement how would it affect our Hydrosphere

Answer 1

Rain Water enters our inner earth through raw land, and if Cementing is done, raw land is covered, which forbid the water to enter the Earth's surface. It decreases the ground water level, which disturbs various essential needs adversely, like farming, etc.

Answer 2

Rainwater seeps into the ground through soil. If these are cemented, then the water table would reduce. Also, because the ground table level is reduced, the plant will not get enough minerals and moisture for their proper growth. Plants die, we dies.
Also, since plants will die, no transpiration will take place in our atmosphere. So water cycle will also get disturbed.