How does urbanization (paving, etc.) affect runoff and infiltration in a small, previously forested drainage basin

Run off increases and infiltration decreases

Explanation:

Urbanization usually involves activities such as paving, etc by people who moved into the area in order to make it more presentable and sophisticated. Urbanization affects runoff by increasing it because water can’t be absorbed into the paved structures so it ‘runs’ off to a place where absorption is high.

Infiltration which involves water being absorbed into the soil also decreases as a result of the pavings.