GEOGRAPHY Revision

Question 1

Hydraulic Action

Answer 1

This is the seer power of the water as it smashes against the river bank and bed, and causes the rock to break apart

Question 2

Abrasion

Answer 2

When pebbles grind along the river bank and bed in a sand-papering effect.

Question 3

Attrition

Answer 3

When rocks that the river is carrying knock against each other. They break apart to become smaller and more rounded.

Question 4

Solution

Answer 4

When the water dissolves certain types of rocks, eg limestone.

Question 5

Traction

Answer 5

Method for moving the largest material.

Question 6

Suspension

Answer 6

carrying river material within the water, so that it floats in the river and is moved as it flows.

Question 7

Solution

Answer 7

This is the dissolved load and occurs only with certain types of rocks that are soluble in the rainwater.

Question 8

saltation

Answer 8

Moves the small stones and grains of sand by bouncing them along the bed.

Question 9

Deposition

Answer 9

This is when a river drops the eroded material it has been carrying. This happens when a river slows down down or loses velocity.

Question 10

formation of waterfall

Answer 10

• a river flows over hard rock sitting on top of soft rock
• a deep plunge pool is eroded at the base of waterfall by hydraulic action and abrasion
• over time, the lip of harder rock is undercut and eventually collapses
• A steep sided gorge is left as waterfall retreats.

Question 11

formation of gorges

Answer 11

Gorges are formed by the continual collapsing and retreating of a waterfall upstream

Question 12

formation of meanders

Answer 12

• it gets wider, deeper, and faster as the river moves from source to mouth
• the water flows faster on the outside bend and slower on the inside bend.
• the outside bend is worn away due to erosion and the inside bend is built up due to deposition.
• we are left with a river cliff and a slip off slope.

Question 13

formation of oxbow lakes

Answer 13

• once meander is formed, continual erosion on the outside bend narrows the neck of the meander.
• river will take the shorter course and cut through the neck.
• the river continues its straighter path and the meander is abandoned.
• new deposition seals off the ends and the cut-off becomes an oxbow lake.

Question 14

Estuary

Answer 14

The tidal part of a river at the mouth where freshwater from the water merges with saltwater from the sea.

Question 15

characteristics of estuaries

Answer 15

• be the point where freshwater meets with salt water
• have mudflats
• be very wide

Question 16

flood

Answer 16

A flood occurs whenever a river overflows its banks.