Levees

Question 1

What is a levee

Answer 1

These are natural or artificial embankments that flank a river in its lower course, helping to restrict and confine the river

Question 2

How are natural levees formed

Answer 2

Natural levees are formed through repeated flooding, when a river bursts its bank it begins to sort straight away

Question 2

How does this sorting take place

Answer 2

The river deposits the majority of its material close to the river with less and less depositing further and further away

Question 2

What happens to velocity

Answer 2

Velocity rapidly decreases once the river is no longer flowing in its channel

Question 3

What happend if this flooding process is repeated

Answer 3

If this process is repeated then the banks gradually build up forming levees

Question 4

During times of low discharge what happens

Answer 4

During times of low discharge, the river remains restricted or confined and so deposition must occur on the channel bed

Question 5

The continues raising of levees does what

Answer 5

The continues raising of levees and and subsequent deposition of the river bed may eventually lead to the river channel rising above the surrounding floodplain

Question 6

If the river channel becomes raised what can this lead to

Answer 6

If this occurs the levees become badly drained because the water cannot flow over the levee and back into the river following a flood

Question 7

As a result of this what feature forms

Answer 7

As a result areas of marshland called backswamps are formed

Question 8

How else are levees used

Answer 8

Levees can also be constructed artificially as a part of flood risk management strategies

Question 9

Where can you find Levees in Ireland

Answer 9

The River Shannon