Over time, rills expand and join together causing gullies.
They are called rills. Rills are small channels that form on sloping land when water flows over the surface, cutting small ditches as it moves downhill.
Tiny rills enlarge to form gullies, which join to form a stream.
Rills are formed by erosion. As soil erodes a thin channel is left, this channel fills with water. Gullies are formed by running water. An area where many rills have formed can turn into a gully.
Artificial rills can be constructed as aesthetic water features.
rills
Rills
Rills and gullies are both landforms formed by erosion caused by flowing water. The main difference is in their size and scale: rills are smaller and shallower, while gullies are larger and deeper. Gullies tend to be more pronounced and have steeper sides compared to rills.
floodplain
Rills
rills
A network of rills, gullies, streams, and rivers in an area.
Rills are a product of soil erosion by water, and can be defined as small incised channels in the soil that result from the actions of flowing water over an unvegetated or partially vegetated soil surface. They can be obliterated by tillage (ploughing over the rills). Where they are too large to be removed by tillage, they are referred to as gullies.