Junior Cycle Geography CYCLONE Managing information and thinking
Look at these photographs of Bandon, Co. Cork, before and after flooding (showing the view up and down the same street). Then answer these questions:
1. Do you think that this area has experienced flooding in the past? Explain your answer. 2. In your opinion, will there be a large or small financial cost to the local economy? Explain your answer. 3. What measures could the local government put in place to prevent this from happening again?
Feature: Meanders A meander is a winding curve or bend in a river. Example: Meanders can be seen in the middle and lower course of the Rivers Shannon and Boyne.
How a Meander Forms
Meanders are formed by a combination of erosion and deposition in the mature and old age stages of a river.
1 Water flows more quickly on the outside of the river bend. The river erodes the bend by a combination of hydraulic action and abrasion. As the current is faster, it undercuts the bank.
2 Water flows more slowly on the inside bend of the river. Material is deposited on the inside bend as the river loses energy here. A point bar can form, which is a build-up of river deposits.
10. How a meander forms B Neck of meander 142 A
Outside of bend – river cliff
Inside of bend – point bar
Erosion
Slowest current on the inside of a bend
A
Deposition Strongest current
Fastest current on outside of a bend
Cross-section through the meander shown below Point bar
Undercutting Deposition Slowest current Fastest current