The River Wharf
Matthew, Robbins, 24/02/11 Year 7 Lions
The River Wharf • The source of the River Wharf starts 20 miles upstream in the Yorkshire Dales. • It flows another 60 miles before meeting the larger River Ouse (forming a confluence) and then flowing another 20 miles before going out to sea via the Humber Estuary.
I looked at a 3 mile stretch of the River Wharf from Barden to Bolton Abbey
The River Wharf – Middle Course Valley more open, more gentle slopes, wider valley bottom Meanders
River channel wider and deeper, it has more water in it
There is a large meander Near Bolton Abbey
This is the river cliff This is part of the river cliff that has eroded and has folded strata showing.
These are pebbles that have been deposited by the river on the inside of the meander as energy has reduced.
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1. The deposits are of a mixed sized from just a few millimetres to 30 cm. They are sub-angular to well rounded. 2. At some points the overflowing river has undercut the trees exposing the roots 3. You can see where the river sometimes goes up on the flood plain leaving small stick and stones 3
The River Wharf – Middle Course For much of the course the river flows at a steady pace. We timed an apple over 10 meters. It covered this distance in 15 seconds. This means that the river speed is 0.67m per second.
There’s an apple somewhere in here
In a couple of places the rock type affects the flow of the river: A seam of harder rock cut across the river creating a small obstruction and a ‘weir’
At one point (The Strid), the river becomes very narrow as the rock changes to the harder millstone grit rock.
The narrow gorge of the Strid runs fast for about 30 metres before widening and slowing down again.
You can just make out a red pepper in the water. The speed of the river at this point is 2.5 metres per second (it took 4 seconds to go 10m).
At the Strid there were potholes. These were caused by water overflowing the channel and its force, and that of the stones it carried, carving out circular patterns. The stones here were rounded and between 2cm and 7cm long.