It's a gully. Rills are smaller ditches cut by running water, but can be plowed over. Once the ditch is so deep it can't be plowed over, it's a gully.
A river.
(Rephrase the question)
No. There is more oxygen in deeper water.
Photosynthetic organisms need light in order to survive. In very deep water there is no light.
Deep currents
the river running through rock wear it down into deep valley with the steep sides what is it called
== == == == == ==
Often times a deep ditch carved over time by running water is called a trench. It can also be called a ditch.
A canion.
arroyo - deep gully cut by an intermittent stream.
Canyon
The deep water can cause both a ditch or a gully. The formation of a gully or a ditch is dependent on the topography of the land and the speed of the flowing water.
The difference between a gully and a ditch is that a gully is a deep ditch. Also a ditch is a lower grade in the earth where water collects and pools.
It is called a moat
Another word for a deep ditch that is dug around a castle is a moat. You could call it a trench, or you could fill it full of water and call it a moat.
The water is 27.6 in deep and slopes up to even with the running surface
The men dug a deep ditch to lay pipes for the new septic tank. I fell in the ditch, but luckily it was dry.
It varies, but it is usually 50 feet deep in most places.
A long, narrow deep ditch.