What type of flow occurs in shallow rills?

In shallow rills, the primary type of flow that occurs is shallow concentrated flow. This is characterized by water moving over a defined channel that is not yet a fully developed stream but is deeper than sheet flow. As the water collects in small rills, it tends to concentrate and move more rapidly compared to sheet flow, which is defined by a thin layer of water spreading evenly across a surface.

Shallow concentrated flow reflects the transition of flow patterns as water begins to become channelized in the landscape. This type of flow is essential in understanding how water travels across certain terrains, particularly in areas prone to erosion and runoff. It also plays a significant role in stormwater management because the focused channels can lead to increased erosion and sediment transport if not properly managed.