Meanders

Página 1

S-shaped loops

All Riverbeds are uneven

Flows faster on outside

River water flows slower on the inside of a meander

erosion on outer banks

Deposition on inner banks

Move downstream gradually

develop on the course of a river

middle-lower courses of river

River Shannon+Liffey

contain shallower and some deeper areas

Uneveness causes river to flow side to side

to avoid obstacles of hard rock also

THIS IS HOW MEANDERS BEING TO FORM

Results in more energy and erodes outer bank

Hydraulic action: force of the water

abrasion: force of the load

2 main processes of erosion

May cause cavitation if forces air bubbles to outer bank

When bubbles burst- emit tiny shock waves that can loosen fragements

(of sand or gravel)

bank caving: when these 3 processes combine to undercut the outerbank

causes it to collapse

Bank caving - causes small river cliffs to form on outer bank

eroded back over time

little energy-deposits material on the inner banks

builds up a slip-off slope on inside

As this grows it develops into a feature of deposition

POINT BAR

cause wideness overtime

gradually erode any interlocking spurs- create flat floodplain on each side of river