Meanders

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

MeanderCross2.jpg

You can use the following words to help you complete the exercise below - river cliff, deposition, outside, neck, erosion, laterally, slip off, slow, hydraulic action, Ox bow, deeper.
Meanders occur in the middle valley and are the result of AND processes on a river.

In this section of the valley the river erodes and migrates across the valley floor over time, widening the valley. Within the river itself, the current is found on the outside of a bend and the slowest current on the inside of the bend, this can be observed on the diagram above. This is because the depth of the water on the outside of the bend is deeper, so there is less and hence higher velocities.

On the shallower inside of the bend sediment can accumulate to form a slope, whereas on the deeper outside of the bend where the current is faster and erosion operates, a river cliff forms.
Over time, this means that erosion occurs on the of meanders bends and deposition occurs on the inside. This process can lead to formation of one of Geography's classic landforms, Ox bow lakes. I

In the diagrams, erosion of the outside of the meander means that the of land becomes narrower and narrower over time.

On the inside of the bend the slow flow encourages the of beaches.

After a long time the neck of land gets totally cut through by erosion processes such as and abrasion.

This cuts off the meander bend which is totally isolated by deposition leaving an lake, which is a crescent shaped lake that will eventually fill with reeds and sediment over time.