IGCSE Geography: Formation of interlocking spurs, waterfalls, meanders, oxbow lakes, floodplains and levees.

IGCSE Geography: Formation of interlocking spurs, waterfalls, meanders, oxbow lakes, floodplains and levees.

River features formed in the Upper Stage of the river

Interlocking Spurs

– Are caused by erosion. It is formed in the upper stage of the river where the river erodes vertically.

– Are ridges produced when the river twists and turns around obstacles of hard rock along its downward pathway.

– These ridges INTERLOCK with one another to form INTERLOCKING SPURS.

Waterfalls

1) A layer of hard rock won’t erode easily so when the river reaches it, any softer rocks on the downstream side are eroded more quickly.

2) This leads to the river bed getting steeper where it crosses the hard rocks and this is when a WATERFALL forms.

3) WATERFALLS can form when the hard rock is horizontal, vertical or dips upstream.

4) At the foot of the waterfall the water wears away the softer rock to form a plunge pool.

5) As the waterfall retreats and eats its way upstream, a recessional GORGE is formed.

Middle stage

Meanders

1) The river now has a large discharge, gentle gradient and lateral erosion.

2) It develops a more winding pathway with large bends- these bends are called MEANDERS.

3) The river twists like a snake- over time the course of the meander migrates downstream.

4) The current is fastest on the outside of the meander curve because the river channel is deeper there- on the inside its shallow so the current is slower.

5) RIVER CLIFFS are found on the meander’s outer edge where the river causes more erosion.

Get quality help now

RhizMan

Verified

Proficient in: Geography

4.9 (247)

“ Rhizman is absolutely amazing at what he does . I highly recommend him if you need an assignment done ”

+84 relevant experts are online

Hire writer

6) Point bars are on the inner edge where sandy material is deposited by the slower-moving river- above river level they are SLIP-OFF SLOPES.

Ox-Bow Lakes

1) MEANDER LOOPS can become so wide the river cannot maintain its flow around the bend. So instead it breaks through the narrow neck of land in between.

2) The outer part of the loop is left ISOLATED from the river as an OX-BOW LAKE.

Lower Stage

Flood Plains

– Is the wide valley floor which the river regularly floods. It is flat and covered by alluvium making it good farmland.

Levees

– Are raised river banks, made of coarse river load material deposited during floods.