The bare soil surface affects runoff because it has no nutrients or real resistants. Run-off rate increases because there is nothing there to absorb the rain water. A porous surface type will absorb a little runoff. A non-porous surface will not absorb much at all. It increases it since there is less plant material to slow down the water.
Run-off rate increases because there is nothing there to absorb the rain water. If the bare soil is comprised of porous-type, then it can absorb a little runoff. But if the soil is non-porous surface, then it will not absorb much at all.
