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Date November 2016 Marks available 1 Reference code 16N.2.SL.TZ0.1
Level Standard Level Paper Paper 2 Time zone Time zone 0
Command term State Question number 1 Adapted from N/A

Question

The resource booklet provides information on the Swakop River Valley. Use the resource booklet and your own studies to answer the following. 

Figure 1(b): Map showing Swakop River in Namibia

Figure 4(b): Investigation into the impact of Mesquite on mammals in the Swakop River Valley

The data in the table show the number species captured by camera shots, in two areas of different
mesquite densities, over 100 days.

Figure 5(a): Graph to show Uranium prices from 1980 to 2013

Figure 6(a): Strategic Environmental Management Plan (SEMP) for the Swakop Valley

Figure 7: Erongo water desalination plant

[Source: Adapted from http://www.world-nuclear-news.org/C-Areva_water_plant_to_supply_Namibian_mines-1908134.html]

State the biome for the area shown in Figure 1(b).

[1]
a.

Identify three natural sources of water available in the Swakop area.

[2]
b.

Outline two reasons why the Swakop river is considered to be ecologically important.

[2]
c.

Outline whether an invasive species such as Mesquite is likely to be r-strategist or K-strategist.

[1]
d.

With reference to the data in Figure 4(b), suggest two conclusions which can be drawn from the camera trap data.

[4]
e.

Justify whether or not Mesquite should be cleared from the Swakop River Valley.

[3]
f.

With reference to Figure 5(a) describe how Uranium prices have changed over time.

[2]
h.

Outline two reasons why the value of resources like Uranium can change over time.

[2]
i.

With reference to Figure 6(a) describe two ways in which Uranium mines have had an impact on water resources.

[2]
j.

With reference to Figures 6(a) and 7, calculate the amount of water available for other uses, after the Erongo desalination plant has met the needs of the three operational mines.

[1]
k.

Using evidence from the resource booklet, justify from an ecocentric viewpoint why the Husab Uranium Project should not be approved.

[4]
l.

Markscheme

desert/savanna

[1]

a.

This question requires “Resource Booklet - Nov 2016 SL paper 2”, available under the "your tests" tab > supplemental materials. 

Swakop river/river runoff/linear oasis;
groundwater/aquifers;
rainfall/precipitation;
condensation/dew/coastal fogs;
ocean. 

3 correct award [2].
2 correct award [1].
1 correct award [0].

[2 max]

b.

This question requires “Resource Booklet - Nov 2016 SL paper 2”, available under the "your tests" tab > supplemental materials. 

range of habitats/passes though different ecosystems;

water supply/linear oasis/corridor of water through the desert/lifeline for animals/buffer against drought;

contains endemic species/higher biodiversity/unusual plants e.g. Welwitschia;

mouth important habitat/feeding ground for birdlife;

interesting study site / place to study invasive species. 

[2 max]

c.

This question requires “Resource Booklet - Nov 2016 SL paper 2”, available under the "your tests" tab > supplemental materials. 

r-strategist because produces many offspring/many seeds/spreads quickly/grows rapidly. 

Award [1] for r-strategist plus valid reason.

[1]

d.

Conclusion (Conc): some species increase whereas others decrease with density of mesquite;
Development (Dev): e.g. Oryx is more common in low mesquite areas but Baboons are less common;

Conc: number of species/species richness is same in high and low mesquite areas;
Dev: i.e. both areas have same number/12 species present;

Conc: species diversity is greater in low mesquite area;
Dev: the diversity index is about 5 in low and about 4 in high mesquite area;

Conc: some species are more common/more commonly photographed than others;
Dev: e.g. most were Steenboks (193 times) and least were Badgers (5 times);

Conc:: some species seem quite unaffected by mesquite;
Dev: e.g. steenboks/jackals have very similar numbers in both areas;

Conc: total no of organisms/activity appears to be higher in mesquite area;
Dev: ...because there are a total of 309 camera shots in high mesquite and only 267 in low / mesquite area may provide better habitat quality/more food/better shelter;

Conc: some species e.g. baboon/kudu/wildcat/klipspringer/porcupine do better in high mesquite;
Dev: perhaps because they feed on mesquite / their competitors are more negatively affected by mesquite;

Conc: some species e.g. Oryx/duiker/rodent do less well in high mesquite;
Dev: perhaps because mesquite replaces important source of food/shelter. 

If development is given with no explicit conclusion, award 1 max for that example.
Credit any reasonable conclusions from the data for [1], with some development or exemplification for the second mark.

Accept other reasonable responses.

[4 max]

e.

This question requires “Resource Booklet - Nov 2016 SL paper 2”, available under the "your tests" tab > supplemental materials. 

Candidates can argue either way:
for example: yes, it should be cleared because:
its negative effect on farms / outcompetes their crops;
it is invasive/spreads rapidly/is non-native displacing local species;
has changed the habitat significantly/research shows negative impact on vegetation, wildlife & birds;
due to aesthetic reasons;
it has a negative effect on water resources in an arid area;

For example: no it should not be cleared because:
it provides a renewable resource for humans;
e.g. firewood/food for humans;
local communities can earn an income from it;
Namibia is a poor country and so helps to address poverty / less than 1 % of thepotential income from Mesquite pods is currently being generated;
Some animals may have adapted to it/feed on it and would be negatively affected (e.g. baboon). 

Accept other reasonable responses.
This is not a “discuss” question, so candidates should opt for one response only, and justifications should be credited for either clearing the mesquite or not clearing the mesquite.

[3 max]

f.

prices decreased gradually from 1980 to 1985/1989;

remained fairly stable between 1985/1989 to 2005;

there was a spike in prices between 2006 and 2008;

prices dropped between 2008–2010;

but have remained higher than pre-2005. 

WTTE / other figures if appropriate are acceptable.

[2 max]

h.

value of resources change over time due to changing needs/shifting cultural values/technological development/accessibility;

as technology made it possible to use uranium for nuclear energy, demand (and price) of Uranium increases;

as countries seek alternatives to fossil fuels / more nuclear power stations opened so uranium increases in value;

adoption of ecocentric values e.g. Sweden, reduces demand for uranium so price falls;

concern over nuclear accidents like Fukushima reduces demand for uranium so price falls;

more mines opened/new deposits found so increase in supply reduces price;

drop in global uranium extraction (due to political decision) may cause increase in price. 

Accept other reasonable responses.
Credit responses referring to dynamic nature of resources, even if they use other resources as example.

[2 max]

i.

uranium mines use huge amounts of water so deplete supplies/lead to over abstraction;

uranium mines contribute to pollution of water resources with radio-nuclides/wastes from mining;

waste rock dumps can lead to diversion of water courses. 

[2 max]

j.

10 million cubic metres [per year] 

[1]

k.

This question requires “Resource Booklet - Nov 2016 SL paper 2”, available under the "your tests" tab > supplemental materials. 

Husab will negatively affect endemic species e.g. Welwitschia;

Husab will disturb natural processes e.g. pollute Swakop river/groundwater from radioactivity/waste rock dump;

impacts of Husab will infringe biorights/degrade intrinsic value of species/ecosystems;

instead of supplying more uranium we should be looking at more renewable energy alternatives;

community involvement is important and this is unlikely with a large scale privately owned mine;

uranium is not a sustainable solution to energy needs as there is a finite amount of uranium;

we should be reducing our use of resources (such as uranium and water) not increasing them;

only 1.8 % of the population is employed in mining anyway so local communities are not benefiting much from the industry;

the tourist value of the area is of greater significance in terms of employment than uranium mining. 

[4 max]

l.

Examiners report

Only a very small minority gave an incorrect answer here, as long as they knew what a biome is; it was occasionally confused with ecosystem.

a.

Most answers managed to gain one mark. The answers commonly confused man-made sources of water like “dams”, so some candidates did not meet the second mark.

b.

The candidates understood the concept of the question and most gained the 2 marks. But a minority did not gain credit since they described economic or social aspects instead of those that are ecologically significant.

c.

Most candidates answered well, with a few exceptions that didn’t realize that ‘outline’ needs reasoning to obtain full marks, and just stated “r-strategist”.

d.

The candidates generally had no problems; nevertheless some candidates couldn’t read the diagram, so it was hard to get full marks since two conclusions were needed.

e.

Most candidates managed 2 marks here, but some ability of written expression was needed to get the three marks.

f.

Most candidates got the two marks.

h.

The candidates could often identify supply/demand principles to the value of a resource; nevertheless, some candidates forgot to link their reasoning to a specific change in value, making 2 max as a result.

i.

Since there were two possible answers depletion and pollution of water resources, most candidates performed well, except for a few who were unable to state the cause of the water pollution.

j.

Most candidates gained the full mark, with a small percentage unable to perform even the simplest mathematical calculations.

k.

Very few candidates were able to get 4 marks, since no clear and explicit links to ecocentric viewpoints were made. Usually they could identify biorights and at times the pollution of groundwater, but not much further.

l.

Syllabus sections

Topic 2: Ecosystems and ecology » 2.4 Biomes, zonation and succession
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Topic 2: Ecosystems and ecology

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