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Date November 2020 Marks available 2 Reference code 20N.1.bp.3
Level SL and HL Paper 1 Time zone
Command term Outline Question number 3 Adapted from N/A

Question

The map shows land use changes that led to the loss of mangrove swamps in selected Southeast Asian countries in 2012.

[Source: Drivers of mangrove loss in Southeast Asia, Daniel R. Richards, Daniel A. Friess, Proceedings of the National
Academy of Sciences Jan 2016, 113 (2) 344–349; DOI: 10.1073/pnas.1510272113.]

Identify the dominant land use that is replacing mangrove swamps on island A.

[1]
a.i.

Estimate the percentage of mangrove swamp loss caused by urban development B.

[1]
a.ii.

Outline one physical factor necessary for the formation of a mangrove swamp.

[2]
b.

Explain two environmental consequences of the loss of mangrove swamps in coastal areas such as those shown on the map.

[6]
c.

Markscheme

Aquaculture

a.i.

Accept answers between 15 and 20 % (units not required).

a.ii.

Award [1] for the factor and [1] for explanatory development.

For example: Mangroves grow in the coastal intertidal zone [1], where freshwater mixes with saltwater [1].

Other possible factors include:

b.

Award [1] for the consequence and up to [2] for development / explanation /exemplification.

For example: Removing the mangroves may mean the coastline is less protected from hurricanes / tropical cyclones [1], as mangroves absorb wave energy [1] and dissipate the force of the storm [1].

Other possibilities include:

c.

Examiners report

Done well.

a.i.

Done well.

a.ii.

Generally no problem but at times the factor was not adequately developed.

b.

This was understood and answered well by most. However, some were not focused on the consequence of the loss, instead discussing the importance of mangroves, for example, for biodiversity but not explaining how their loss would have environmental consequences.

c.

Syllabus sections

Option B: Oceans and coastal margins » B.3. Managing coastal margins » B.3.3. Management of coral reefs and mangrove swamps
Option B: Oceans and coastal margins » B.3. Managing coastal margins
Option B: Oceans and coastal margins

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