SAC 2 revision

Question 1

Define ‘land cover’ and provide 2 examples.

Answer 1

The observed (bio)physical cover on the Earth’s surface.

Bare areas, water bodies.

Question 2

Define ‘land use’ with examples.

Answer 2

The purpose to which land cover is committed.

Recreation, dwellings.

Question 3

Define ‘drylands’.

Answer 3

Regions of the world that are climatically zoned as arid, semiarid and dry subhumid.

Question 4

Define ‘afforestation’.

Answer 4

The establishment of a forest or stand of trees in an area where there was no forest.

Question 5

Define ‘glacier’.

Answer 5

A body of ice formed on land and in motion, confined by terrain, most commonly valleys.

Question 6

Define ‘ice sheet’.

Answer 6

Masses of ice not confined to valleys that bury large tracts of land beneath them.

Question 7

State the processes that create landform glacial features.

Answer 7

Erosion, deposition.

Question 8

State how moraine is formed.

Answer 8

Ice scrapes, scours and removes rock as it slowly moves down the valley floor. This erosion creates moraine (material transported by a glacier).

Question 9

Define ‘moraine’.

Answer 9

A mass of rocks and sediment carried down and deposited by a glacier.

Question 10

Explain the process of glaciation:

Answer 10

Ice and snow accumulate at high altitudes and flow downhill under its own weight to a point called the terminus where ice had melted. Meltwater flows from this point. Along the glacier, ice starts melting instead of accumulating and the colour changes to grey. This process is called ablation.

Question 11

Define ‘firn’ snow.

Answer 11

Very compacted snow.

Question 12

State 4 causes of desertification in China.

Answer 12

Increasing pressure on land’s resources to support growing population.

Expansion of cropland into areas receiving low rainfall.
Windy climate.

Climate change contributing to declining rainfall and falling water tables.

Centuries of unsustainable intensive farming practices.

Question 13

State the local responses to desertification in China and where.

Answer 13

Many farmers located in areas that have undergone desertification have turned to tourism as a way to compensate for loss of income e.g. Camel riding, dune sledding, and providing accommodation.

A resident in North West China Shaanxi province has turned over 16,000 hectares of desert into an oasis over a period of 30 years.

Question 14

State the national response to desertification in China.

Answer 14

A project called the Great Green Wall of China (GGW) was launched in order to help prevent the movement of sand and allow recovery of the ecology and environment. The government uses methods of aerial seeding and cash incentives to farmers to plant trees and shrubs.

Question 15

State and describe one technique used to stop desertification.

Answer 15

Wind corridors/breaks are plastic/straw grids which halt wind erosion, allowing the regrowth of the environment and ecology.

Question 16

List 3 benefits and 3 drawbacks to GGW.

Answer 16

Benefits:
Increase in forest cover.
Decrease in wind storms.
Increase in frost free days.
Improved crop yields.

Drawbacks:
Very small percentage of trees survived.
Low life expectancy due to cuttings used.
Monoculture plantations encouraging disease outbreaks.
Groundwater levels dropped significantly.

Question 17

State the factors that have driven deforestation in Sumatra.

Answer 17

Social: Corruption; cash incentive; demand for commodities.
Environmental: forest fires; availability and accessibility of natural resources.
Economic: need for economical development.
Political: Poor law enforcement and regulations.
Technological: advanced technology of motor vehicles and equipment e.g mining drills.

Question 18

What is the national response to deforestation in Sumatra? How effective is it?

Answer 18

The government believes the economic benefits outweigh the environmental impacts; they have distributed permits allowed 70% of the remaining forest cover to be defrosted. However in 2013 and moratorium on deforestation of primary forests was extended for 2 years though proved inadequate as corruption and poor law enforcement was rife.

Question 19

Give an example of a technology used to assess deforestation in Sumatra. How has it helped?

Answer 19

Global Forest Watch 2.0 (GFW 2.0) is an online platform which facilitates the online reporting of forest extent, as well as the enforcement of existing forest management regulations. The platform brings together data derived from satellites in near real time and provides aerial images of the global distribution of forests for public viewing. GFW 2.0 removes the previous challenges of authorities not detecting illegal deforestation until months or years afterwards and aids in decisions about land use.

Question 20

List and define the 3 processes studied and the locations studied.

Answer 20

Greenland - Glaciation: The process by which an area becomes covered with glaciers or masses of ice.

China - Desertification: The process by which fertile land becomes desert.

Sumatra - Deforestation: The process by which a forest is transformed into cleared land through the clearing of trees.

Question 21

Define one natural process that has changed land cover over time and how it has.

Answer 21

Climate change - A long term change in the Earth’s climate.
Climate change is one of the factors affecting rates of desertification by increasing the intensity of drought in semi arid and subhumid regions. Farming areas will need to adapt to changes in climate with changes in cropping and intensity of animal grazing. Roughly 21,000 - 18,000 years ago the average temperature on Earth was approximately 4 C lower than present (15C), sea level was approximately 100m lower and the Earth’s climates were predominantly more so classified as ‘extreme desert’. The UN estimated 2 billion people are at risk from desertification.

Question 22

Define and provide an example of glacial retreat.

Answer 22

Glacial retreat is when glacial melt outpaces the accumulation of new snow and ice.
The Jakobshavn Isbrae Glacier is a glacier that extends between the Greenland ice sheet and the ocean. This glacier is the worlds fastest and has increased in velocity from 7km/year in 1985 to 14km/year in 2006. The glacier has retreated over 40km since 1851

Question 23

What are our average temperatures now? How much have they increased?

Answer 23

Since 1880 the Earth’s average temperature has increased by 0.85C, making the present average 15C. This has correlated with a decline in the distribution of ice in the Arctic. Scientists believe this represents losing about 40% of the ice that was present in the Arctic since the 1970’s. So far the 10 hottest years on this planet have occurred since 1997.

Question 24

State the geography of Greenland.

Answer 24

Greenland is the world’s largest island (2.2 million sqkm). Its ice sheet is approximately 1.7 million sqkm (80%) of the island, in some places it is found to be 4km thick. The country is dome like in shape with the elevation reaching its highest inland (more than 3000m). It contains 11% of the Earth’s freshwater supply.

Question 25

State how cryoconite forms.

Answer 25

Cryoconite begins as an airborne sediment spread by wind. The sediment is a combination of dust from Central Asian deserts, matter from volcanoes, and particles from European coal fired power plants.

Question 26

State how Greenland’s melt has been accelerated by cryoconite.

Answer 26

As the colour of cryoconite is dark it decreases the albedo of the ice, thus it melts the ice and leads to the formation of mourns, which can cause the ice sheet to melt from the base.

Question 27

State and describe a response to the melting of Greenland.

Answer 27

Oceans Melting Greenland (OMG) is a project initiated by NASA in order to assess the extent of how oceans are melting
Greenland’s ice from below and give an estimate of future sea level rise. Over a five year campaign, OMG will observe changing water temperatures and how the marine glaciers react to the presence of warm, salty Atlantic water. OMG will use a NASA’s G 3 aircraft to fly the ‘Glacier and ice Surface Topography Interferometer’ in order to generate high resolution, high precision elevation measurements of Greenland’s glaciers.

Question 28

Describe the scale of Greenland’s melting.

Answer 28

Currently Greenland is losing a gigaton of ice per day. Between 2004 and 2011, Greenland’s net annual ice loss was 234 cubic km of water which is enough to lift sea levels by average of 0.65 mm.

Question 29

Describe the location of Greenland.

Answer 29

Greenland is found between 60 and 83 degrees latitude North of the equator, neighbouring Canada, Denmark, and Norway. It is apart of the North American continent.

Question 30

State the effects from the melting of Greenland’s ice.

Answer 30

If all melted would contribute a global sea level rise of 7m. Annual melting of Greenland ice has caused sea levels to rise globally by 0.5mm per year over the last 30 years, whilst 1 billion people live in areas that would be flooded by a 1m rise in sea level. So far the melting of ice has uncovered Greenland’s mineral resources, providing an economic advantage for the country.