IB ESS HL 4.2 Water Access Use and Security Questions

Practise IB ESS HL 4.2 by analysing demand, pollution, climate and access evidence and evaluating water strategies under competing impacts.

Exam points

Analyse water-demand and scarcity data to explain stress and unequal access.
Evaluate physical and economic limits on storage, treatment and distribution.
Evaluate conservation, desalination, dams and transfers through social, economic and ecological effects.
Assess transboundary and industrial solutions using conflict, displacement and ecosystem impacts.

Covered syllabus points

4.2.1—Water security definition 4.2.2—Factors affecting water availability 4.2.3—Water supply increase needs 4.2.4—Increasing water supplies 4.2.5—Water scarcity types 4.2.6—Domestic water conservation 4.2.7—Industrial water conservation 4.2.8—Water scarcity mitigation strategies 4.2.9 (HL)—Freshwater planetary boundary 4.2.10 (HL)—Governance for sustainability 4.2.11 (HL)—Water footprints 4.2.12 (HL)—Citizen science role 4.2.13 (HL)—Water stress definition 4.2.14 (HL)—Water stress threshold 4.2.15 (HL)—Water stress causes 4.2.16 (HL)—Transboundary disputes 4.2.17 (HL)—Industrial-level water stress solutions 4.2.18 (HL)—Freshwater production impacts 4.2.19 (HL)—Inequitable access impacts

[Maximum number: 2]

Figure:World population growth, 1750–2050

Figure 2 shows world population growth from 1750 to 2050.

The lack of food and fresh water may limit the rate of global population growth beyond 2050.

Identify two reasons that may cause fresh water supply to be limiting.

[Maximum number: 6]

Figure:Water transfers and transformations after rainfall in forest and urban environments

Figure:Global water demand by sector for 2014 and projections for 2025 and 2040

(a)

Calculate the percentage of water projected to be used for agriculture in 2025, shown in Figure 2(b).

[ 1 ]

$\frac{2500}{4250}\times100=58.8\%$ , or 59%.

(b)

Suggest one reason for the projected decrease in the demand for water in agriculture between 2014 and 2025, shown in Figure 2(b).

[ 1 ]

(c)

Outline two reasons why water demand shown in Figure 2(b) is projected to increase globally from 2014–2040.

[ 2 ]

(d)

Outline two strategies to meet an increasing demand for domestic water.

[ 2 ]

[Maximum number: 7]

Evaluate rainwater harvesting and desalination as a means of sustainably managing water supply.

[Maximum number: 1]

Figure:Projected global water scarcity from 1995 to 2025

State the general pattern of change in global water scarcity predicted from 1995 to 2025 as shown in the water-scarcity map shown above.

[Maximum number: 2]

Figure 5: Dam storage, urban and agricultural water use, and rainfall in the Western Cape, 2014-2018

Figure:Dam storage, urban and agricultural water use, and rainfall in the Western Cape, 2014-2018

Outline two strategies that may have been used to reduce urban water use, as shown in Figure 5.

[Maximum number: 2]

Figure:Water stress for selected crops

Water stress is the total annual extraction of water as a proportion of the renewable supply in a given area. If the extraction represents 40 % or more of the available supply it is described as a high risk area.

Identify two strategies that could be used to grow crops in areas of high water stress.

[Maximum number: 3]

Figure 9(a): Fact file on water resources in Beijing
Beijing is water scarce. Water use per person has decreased, but total demand has increased because of population growth.
By 2020 about 70% of Beijing water was supplied from the South-North Water Diversion Project.
The project expanded the Danjiangkou dam and reservoir, transfers water over 1200 km to Beijing, generates hydroelectricity and provides flood control.

Figure 9(b): Central route of the South-North Water Diversion Project

With reference to Figures 9(a) and 9(b), evaluate the South–North Water Diversion Project.

Cons:
a. people relocated from the area to be flooded / loss of communities/villages / loss of livelihoods in the area;
b. loss of habitat to area that was flooded / loss of habitat to construction of the canal/pipeline that carries the water from the reservoir to Beijing / destruction of habitat caused by building of road to the construction site;
c. reduction in flow into the Yangtze river affecting wildlife/fish populations/human settlements / loss of water for the Shanghai area;
d. dam blocks fish migration;
e. dam disrupts/reduces flow of sediments downstream;
f. (weight of water in dam) can trigger seismic movement/earthquakes;
g. increase in insect vectors/water-borne diseases (e.g. bilharzia/malaria);
h. rotting vegetation in dam can release greenhouse gases (methane and carbon dioxide) / it is energy intensive to build and equipment used release greenhouse gases / $\mathrm{CO}_{2}$ ;
i. potential loss of water from canals/dams due to evaporation / potential loss of water from canals due to long distance of transfer to Beijing ( 1200 km );
j. it is expensive to construct / pipelines will require continual maintenance which is expensive;
k. over-dependency on a single source could be an issue e.g. drought in the Shanghai region;

Pros:
l. production of hydroelectric power / generates electricity sustainably;
m. provides flood control;
n. provides water supply for Beijing residents / improves availability of safe water / decreases water scarcity;
o. water available for irrigation;
p. water available for industry;
q. avoids use of groundwater/polluted surface water;

Balanced conclusion (example):
While the benefits to Beijing in terms of addressing water scarcity would be enormous, the environmental impacts (e.g. of loss of habitats) and social impacts (e.g. loss of villages and communities) of increasing the dam size would outweigh the benefits.

Award up to [2] for cons and up to [2] for pros; [3] maximum overall. Award up to [2] if only one side is given. A balanced conclusion can earn [1], but is optional.
Conclusion is not mandatory and 3 marks can be achieved through consideration of both cons and pros.

[Maximum number: 1]

Figure:Water stress for selected crops

State the crop that is under the greatest water stress.

[Maximum number: 3]

Figure:Water stress for selected crops

Identify three factors that may lead to an increase in water stress.

[Maximum number: 2]

Figure:Water as a strategic resource

The cartoon below is a comment on the strategic importance of each country securing its own water supply.

Suggest one reason why "in the future, wars will be fought over water".

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Covered syllabus points

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Question (a)

Question (b)

Question (c)

Question (d)

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