Overland flow
Overland flow is the portion of water which cannot infiltrate the surface so has to travel over the ground surface towards a stream channel.
This is further split into 2 categories
- Infiltration excess overland flow - occurs when water cannot infiltrate the surface because the maximum rate of infiltration has been exceeded.
- Saturation excess overland flow - occurs when the surface is saturated preventing soil from infiltrating.
High rates of overland flow are found in urban areas as concrete and asphalt surfaces do not allow for infiltration of water.