upper course features course features 2015.pdf · v shaped valley iinterlocking spurs potholes...

RIVERS

The point where the river begins

A small river or stream that joins another one.

Where 2 rivers meet

The part of the river that the tide enters

The point where the river meets the sea

The whole area of land that is drained by the river and its tributaries

Drainage Basin

The high ground that separates two river systems Vocabulary of Rivers

Rivers have 3 courses or

stages

The Upper Course or Youthful Stage

The Middle Course or Mature Stage

The Lower Course or Old Age Stage.

Youthful Stage – the river flows very fast up in the mountains – it is only a small stream here. The river has steep sides and a narrow valley

Mature Stage – the river begins to flow in the lowlands – the valley has a wide floor and gentle sides

The Old Age Stage – the floor of the river valley is very flat. It flows towards the sea.

RIVERS AS THEY FLOW, WEAR

AWAY THE ROCKS ON THEIR BEDS

AND BANKS.

THEY TRANSPORT THIS

MATERIAL – CALLED ITS LOAD

THEY DEPOSIT THEIR LOAD

ALONG THE WAY.

RIVERS ERODE IN FOUR WAYS

THE FORCE OF THE WATER WEARS AWAY THE

ROCK – HYDRAULIC ACTION

ROCKS CARRIED IN THE RIVER’S WATER

WEAR AWAY THE BED AND THE BANK OF

THE RIVER – ABRASION

THE PEBBLES IN THE RIVER WATER BOUNCE

OFF EACH OTHER AND ARE ROUNDED -

ATTRITION

MINERALS IN THE WATER DISSOLVE SOME

ROCKS SUCH AS LIMESTONE – SOLUTION

How rivers transport their load

THE YOUTHFUL STAGE OF

A RIVER

THE UPPER COURSE OF A RIVER CONTAINS

THE FOLLOWING FEATURES

V SHAPED VALLEY

IINTERLOCKING SPURS

POTHOLES

RAPIDS

WATERFALLS

V SHAPED VALLEYS ARE ALWAYS FOUND HIGH UP IN THE MOUNTAINS WHERE THE STREAM IS BEGINNING TO FLOW.

FREEZE THAW ACTION ALSO WEARS

AWAY THE ROCKS ON THE VALLEY SIDES

V shaped valley and interlocking spurs

Waterfalls

Angel Falls,

Venezuela,

plunge

979m onto

lowland in

valley

Niagara

Falls,

Canada

Iguacu Falls, South America

Canada

The pebbles swirled around by the

water as it flows along its course.

The pebbles act like a drill in the bed

of the river and drill holes into it.

These holes are called POTHOLES.

They can join together over time so

that the bed of the river is deepened.