A depression in the ground with a higher elevation on either side.
you can find them on the north side of river elid at the hunter ground there look on the map
a bank erosion is when the river side takes the dirt and soil from the sides of the ground we stand on were we what to jump in at
The main river of Nottingham and Staffordshire is the River Trent.
Ground water
I think you refer to the Watershed.... say rain falls on a mountain side & some of it eventually flows into the River Anything & some flows into the next valley, the River Zoobeedoobeedoo. Where the dividing line is, (Between the Anything & the Zoobeedoobeedoo) is the Watershed.
By the river Thames
cliff on the side of a river
Water in the ground goes to the river(near)
no you can not compare it other than saying that the top of the river has the high ground and the lower part of this is dead one end has the high ground and the other has the low ground so one is higher then the other
the river source is where the water bubbles up from under the ground and creates a river.
a waterfall <><><> A river