meanders and oxbow lakes

Question 1

Where are meanders and oxbow lakes found?

Answer 1

In the middle course

Question 2

What is the thalweg?

Answer 2

The fastest flow (of the water)

Question 3

What happens first in the formation of a meander?

Answer 3

An obstruction in the river’s path forces a thalweg to form. The water that flows fastest on the outside of the river, eroding the outer bends of the slightly meandering river

Question 4

What happens second in the formation of a meander?

Answer 4

The thalweg continues to erode the outer bend of the river, but also now deposits material on the inside of the bend. This causes the river to ‘move’ as its bends get bigger

Question 5

What is the shape of the channel where meanders are formed (in the middle course)?

Answer 5

The channel is asymmetrical. On one side (where erosion happens) there is a river cliff; on the other side (where deposition occurs) there is a slip-off slope

Question 6

How does an oxbow lake form?

Answer 6

As the meanders of a river continue to ‘grow’, they eventually intercept at a “meander neck”. The area where the meander was gets material deposited there (because the flow is weaker), and it is eventually cut off