Runoff of water is said to occur when the water portion of an area flows as surface water rather than being absorbed into the ground or evaporated into the atmosphere. The amount of runoff that occurs in a particular area is influenced by certain factors including land use, amount of vegetation, slope of land, soil type etc.
The way a portion of land is used, the structures built on it can increase the amount of runoff on that land. A natural, unexploited land will be less affected by runoff because water has a higher chance of infiltrating the soil.
