Water on land, Geography

Question 1

Formation of a waterfall

Answer 1

Hard rock layered ABOVE soft rock
soft rock solutes and leaves an overhang
overhang falls into plunge pool, creates traction and erodes.
hydraulic action smashes into the river bed
the waterfall retreats and forms a gorge

Question 2

4 methods of erosion

Answer 2

Hydraulic action
solution
attrition
abrasion

Question 3

4 methods of transportation

Answer 3

Traction
saltation
suspension
solution

Question 4

Define suspension

Answer 4

Very small grains of sand/silt are carries along with the water

Question 5

Define saltation

Answer 5

Small stones bounce along the river bed in a leapfrogging motion

Question 6

Define Traction

Answer 6

large rocks and boulders are rolled along the river bed

Question 7

Define Abrasion

Answer 7

Material carried wears away the bed+banks causing lateral and vertical erosion

Question 8

Define Attrition

Answer 8

The river erodes the load is carrying, as the particles collide they become smaller

Question 9

Define Hydraulic action

Answer 9

The sheer force of the water hitting the river banks

Question 10

Define solution

Answer 10

Water reacts with the rock and dissolves it, the higher the acidity the faster it solutes

Question 11

Formation of an oxbow lake

Answer 11

Fast flow of water on the outside of the meander erodes the banks with hydraulic action and abrasion, this narrows the neck bringing it closer together.
During a flash flood the river takes the quickest route possible to the sea.
The meanders neck has eroded and gets blocked by deposition causing an oxbow lake. The river cannot meander again as the fastest flow is now in the middle

Question 12

Formation of a levee

Answer 12

Before a flood the river flow is normal meaning the energy is confined to the channel so the velocity is high.
When the river floods it overflows therefore it looses energy and deposits the heaviest material.
After many floods a levee is built up.

Question 13

MEDC flooding case study

Answer 13

Boscastle, Cornwall

Question 14

Date of boscastle floods

Answer 14

Monday 16th august 2004

Question 15

Effects of the boscastle flood

Answer 15

6 buildings and 1 bridge collapsed.
Buildings ruined by rainwater.
The road which passes through the village was washed away.
Bridges were blocked by trees and cars.
The clean up bill was over 1million pounds.
10ft wall of water swept through the village.

Question 16

Cause of Boscastle floods

Answer 16

Ground was already very saturated which increased surface run off.
More than 70mm of rain in just 2 hours on the day.
The rivers valency and Jordan flow from bodmin moor which is covered in a thin layer of impermeable peat

Question 17

Response of Boscastle floods

Answer 17

Ehe RAF and coastguards deployed 7 helicopters to rescue people.
more than 120 people were airlifted to safety .
Coastguards watched the harbour t make sure no one was swept away.
Tourists and residents were evacuated to the village hall

Question 18

LEDC flood case study

Answer 18

Bangladesh

Question 19

Date of Bangladesh flood

Answer 19

July 2004

Question 20

effects of Bangladesh flood

Answer 20

800 dead
40% of Dhaka submerged
60% of the whole country submerged
30 million homeless
100,000 suffered diarrhoea because of floating sewage
$7 billion worth of damage

Question 21

Causes of the Bangladesh flood.

Answer 21

Seasonal monsoon rains
worst rain for 50 years
the river ganges and Brahmaputra converged
70% of the country is 1 metre above sea level
snow melt from the Himalayas
deforestation due to increasing population
no flood defences

Question 22

responses of the Bangladesh flood

Answer 22

Hygiene kits handed out
charities such as water aid and unicef handed out resources
relief sent by the British government
125 million donated by other countries
world food programme handed out high energy biscuits to 80,000 children