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Date November 2020 Marks available 7 Reference code 20N.2.SL.TZ0.6
Level Standard Level Paper Paper 2 Time zone Time zone 0
Command term Explain Question number 6 Adapted from N/A

Question

Outline two factors that enable a human population to increase its local carrying capacity.

[4]
a.

Explain how the growth in human population can affect local and regional water resources.

[7]
b.

To what extent would different environmental value systems be successful in reducing a society’s ecological footprint?

[9]
c.

Markscheme

range of resources used;
…means that a local human population can consume/exploit more resources available locally than any other species;
human ingenuity/substitution;
…means that humans are capable to find alternative resources when one is near depletion;
variations in lifestyle;
…means that people can be flexible in their mode of consumption of limited/dwindling resources;
importation of resources;
…means that a wealthy population can grow beyond the boundaries set by their local resources;
technological developments; (can be linked to all previous factors)
…allows humans to use available resources more efficiently / discover new resources / import resources from far away;

Note: Award [1] for identifying each factor and [1] for outlining how it enables increase in carrying capacity.

a.

growing human populations result in increased need for water for domestic/drinking/cooking use;
Commercial development/industrialisation/factories increase water demand;
increasing food demand entails increased irrigation/water for crops/agriculture;
increasing populations may increase poverty and thus economic water scarcity;
areas/locations/countries that have physical water scarcity would be mostly affected;
…causing freshwater land resources (lakes, rivers) to dwindle / risking sustainability of freshwater- resources / depletion of aquifers;
…often resulting in conflict over access to water;
increased groundwater abstraction may lead to intrusion from salt water;
(increased) industrial effluents can cause water (toxic) pollution;
dam construction to meet higher demands of growing population can affect sustainability of that water source;
increasing populations can stimulate technological innovation and greater efficiency of water use / management;

The points above may be credited through a case-study eg

case study: Egypt’s population is growing fast, thus increasing demand for drinking water [1]. Need for more food in a country would increase need for irrigation [1] which would cause cause reduction in groundwater [1] in a country with scarce water resources (most water comes from the Nile river) [1]. Government has constructed dams in the Nile basin, which are threatening conflict between Egypt and its neighbouring countries [1] decreasing the amount of water downstream (due to evaporation) [1: different enough from groundwater/aquifer depletion] and decreasing silt which used to fertilize plains [1: an impact on water quality].However more electricity is produced [no mark as IRRL] and provision of irrigation water is more stable/controlled (not dependent to seasonal floods) [1 for positive impact on water resources];

b.

Refer to paper 2 markbands, available under “your tests”  tab > supplemental materials.

The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although “ESS terminology” has been conflated with “Understanding concepts”). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.

Answers may include:

c.

Examiners report

Weaker responses merely vaguely suggested an increased use of resources rather than methods of exploiting the fixed resources of an environment more efficiently/thoroughly.

a.

This question was generally well-answered with a good range of impacts on water sources and other issues of water supply.

b.

Many candidates approached this question well. Weaker responses had vague or inaccurate perceptions of the different value systems and so came up with inappropriate or equally vague strategies for reducing ecological footprint.

c.

Syllabus sections

Topic 4: Water and aquatic food production systems and societies » 4.2 Access to fresh water
Topic 4: Water and aquatic food production systems and societies

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