Unit 4 : Rivers

Question 1

What is sustainability ?

Answer 1

Sustainability consists of fulfilling the needs of current generations without compromising the needs of future generations, while ensuring a balance between economic growth, environmental care and social well-being.

Question 2

Hard engineering with examples

Answer 2

Hard engineering involves building artificial structures, which try to control natural river processes at a local scale. Examples include : sea walls, rock armor, gabions and groynes

Question 3

Sea walls ( definition )

Answer 3

Concrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.

Question 4

Sea walls ( adv and dis )

Answer 4

Advantages
Effective at protecting the base of the cliff.
Sea walls usually have promenades so people can walk along them.

Disadvantages

Waves are still powerful and can break down and erode the sea wall.
Expensive - approximately £2,000 per metre.
Ugly

Question 5

Rock armor ( def )

Answer 5

Large boulders placed at the foot of a cliff. They break the waves and absorb their energy.

Question 6

Rock armor ( adv and dis )

Answer 6

Advantages

Cheaper than a sea wall and easy to maintain.
Can be used for fishing.
Disadvantages

They look different to the local geology, as the rock has been imported from other areas.
The rocks are expensive to transport.

Question 7

Gabions ( def )

Answer 7

Rocks are held in mesh cages and placed in areas affected by erosion.

Question 8

Gabions ( advs and dis )

Answer 8

Advantages

Cheap - approximately £100 per metre.
Absorbs wave energy.
Disadvantages

Not very strong.
Looks unnatural.

Question 9

Groynes ( def )

Answer 9

Wooden or rock structures built out at right angles into the sea.

Question 10

Groynes ( adv and dis)

Answer 10

Advantages

Builds a beach - which encourages tourism.
They trap sediment being carried by longshore drift.
Disadvantages

By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.
They look unattractive.

Question 11

Soft engineering

Answer 11

Soft engineering does not involve building artificial structures, but takes a more sustainable and natural approach to managing the coast

Question 12

Beach nourishment ( def )

Answer 12

Sand is pumped onto an existing beach to build it up.

Question 13

Beach nourishment ( adv and dis )

Answer 13

Advantages

Blends in with the existing beach.
Larger beaches appeal to tourists.
Disadvantages

Needs to be constantly replaced.
The sand has to be brought in from elsewhere.

Question 14

Reprofiling ( adv and dis )

Answer 14

Advantages

Cheap and simple.
Reduces the energy of the waves.
Disadvantages

Only works when wave energy is low.
Needs to be repeated continuously.

Question 15

Reprofiling def

Answer 15

The sediment is redistributed from the lower part of the beach to the upper part of the beach.

Question 16

Dune nourishment (def)

Answer 16

Marram grass planted on sand dunes stabilises the dunes and helps to trap sand to build them up.

Question 17

Dune nourishment ( dis and adv )

Answer 17

Advantages

Relatively cheap.
Maintains a natural-looking coastline.
Disadvantages

Can be damaged by storm waves.
Areas have to be zoned off from the public, which is unpopular.

Question 18

erosion 4

Answer 18

hydraucolic action, attrition, abrasion, corrosion

Question 19

transportation 4

Answer 19

traction, saltation, suspension, solution

Question 20

how do dams help prevent flooding

Answer 20

dam buiding can reeduce teh amount of water flow, if there is a possibility of flooding, sluices in the river can be closed so that some wtaer will remain behind in the resevoir

Question 21

three gorgers dam location

Answer 21

huebi province, yangteze river

Question 22

when did constrcution begin and when did it end

Answer 22

1994,2008 (reach full electriity production capacity in 2012)

Question 23

cost (dam)

Answer 23

accoridng to chinease officials it cost 24 B hwover outside sources sya it coudl be upto three times thiks cots. funding came from government funds and other bonds

Question 24

ecpnomic benifts of the dam (5)

Answer 24

1. help china produce it own energy
2. reduce reliance o oil from other countries
3. less economic lossses from the floods
4. positivly impact tourism becasue more scenic routes are now accessable
5. larger ships can transport products opeing the region to inceased tarde

Question 25

social consequnces 4

Answer 25

1. displced more people than the three preivous largest chinese dams combind
2. nearly 13 cities, 140 towns and 14000 villages destroyed
3. 1.4 million peple displaced
4. protects over 100 million people fruther downstream

Question 26

envirnemntal impacts 5

Answer 26

1. reduces cola consumption by upoto 31 million tonnes annually
2. 80% of teh land is experiancing problems with erosion
3. (produces over 40 million tonnes of sediment that is deposited into teh river each year)(the sediment places weight on teh seismic fault the dam happpens to sit on)
4. the river contains over 300 fish species, teh dam prevents fishes from spawning upstrem and so diminishes population iszes
5. 100,000 acres were flooded (accoounted for 10% of chinas grain supply)

Question 27

what could have been done instead of teh dam