Secondary 3 Geography Resources Sustainability Quiz

Secondary 3 Geography Quiz - Resources Sustainability (Answer Key)

Total Marks: 40

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Section A: Multiple Choice Questions (10 marks)

1. Answer: B [1]

Explanation: A renewable resource is one that can be replenished naturally at a rate comparable to or faster than its rate of consumption (e.g., solar energy, wind, sustainably managed forests). Option A describes a non-renewable resource. Option C is incorrect — renewable resources are found globally. Option D is not a defining characteristic.

2. Answer: B [1]

Explanation: Carrying capacity is the maximum population size of a species that an environment can sustain indefinitely without degrading the environment's ability to support future populations. It applies to resource availability (food, water, habitat) and waste absorption capacity.

3. Answer: D [1]

Explanation: Water stress occurs when demand exceeds supply (C) AND when annual supply falls below certain thresholds. The Falkenmark Water Stress Indicator defines water scarcity as <1,000 m³/person/year (B) and water stress as <1,700 m³/person/year (A). Both B and C correctly describe aspects of water stress.

4. Answer: B [1]

Explanation: Demand-side management reduces water demand through policies, pricing, and behavioural change. Tiered pricing (higher rates for higher usage) discourages excessive use. Options A, C, and D are supply-side strategies (increasing supply).

5. Answer: B [1]

Explanation: The ecological footprint measures the biologically productive land and water area required to produce the resources a population consumes and to absorb its waste (especially carbon emissions), using prevailing technology. It is expressed in global hectares (gha).

6. Answer: B [1]

Explanation: Virtual water (or embedded water) is the volume of water used to produce a good or service, which is then "traded" virtually when the product is traded. For example, importing 1 kg of wheat imports ~1,300 litres of virtual water.

7. Answer: C [1]

Explanation: Natural gas is a fossil fuel formed over millions of years; it is finite and non-renewable on human timescales. Solar, wind, and biomass (if sustainably managed) are renewable.

8. Answer: B [1]

Explanation: The circular economy aims to decouple economic growth from resource extraction by keeping products, components, and materials at their highest utility and value through reuse, repair, refurbishment, and recycling — closing the loop.

9. Answer: B [1]

Explanation: Desalination (reverse osmosis) requires significant energy (high operational cost and carbon footprint if fossil-fuelled) and produces concentrated brine discharge that can harm marine ecosystems if not properly managed.

10. Answer: D [1]

Explanation: Singapore's Four National Taps are: (1) Water from local catchment, (2) Imported water (from Johor), (3) NEWater (high-grade reclaimed water), and (4) Desalinated water. Singapore has no significant deep aquifers for groundwater extraction.

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Section B: Structured Questions (18 marks)

11. Figure 1: Water Stress Levels

(a) Qatar [1]
Marking note: Accept "Qatar (4.97%)" or just "Qatar".

(b) 4.56% [1]
Marking note: Must include % sign or "percent". Accept 4.56.

(c) Two physical factors: [4]
Marking: 2 marks per well-explained factor (1 for identification, 1 for explanation).

1. Arid climate / Low rainfall: These countries are located in arid/semi-arid zones (Middle East, North Africa) with very low annual precipitation (<200 mm/year), limiting natural freshwater recharge.
2. High evaporation rates: High temperatures year-round lead to high evapotranspiration rates, causing rapid loss of surface water and soil moisture, reducing effective water availability.
3. Limited surface water / river systems: Few perennial rivers; most water comes from ephemeral wadis or non-renewable fossil aquifers.
4. Geology — lack of renewable aquifers: Many rely on fossil groundwater (non-renewable) rather than actively recharged aquifers.

Any two well-explained factors = 4 marks.

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12. Figure 2: Singapore Water Demand Projection

(a) Trend description: [2]
Marking: 1 mark for "increasing", 1 mark for "total demand approximately doubles / rises from ~430 to ~660 mgd" or "non-domestic demand doubles while domestic stays stable".

• Total water demand is projected to increase steadily from about 430 million gallons per day (mgd) in 2020 to about 660 mgd in 2060 (approx. 53% increase).
• The increase is driven entirely by the non-domestic sector, which doubles from ~210 to ~430 mgd, while domestic demand remains relatively stable (~210 to ~230 mgd).

(b) Percentage increase calculation: [2]
Marking: 1 mark for correct formula/working, 1 mark for correct answer.

• Non-domestic 2020: ~210 mgd
• Non-domestic 2060: ~430 mgd
• Increase = 430 – 210 = 220 mgd
• % increase = (220 / 210) × 100 ≈ 104.8% (accept 105% or "approximately doubles / 100% increase")

(c) Reason for non-domestic increase vs stable domestic: [3]
Marking: 1 mark for identifying economic/industrial growth, 1 mark for linking to water-intensive industries, 1 mark for contrasting with domestic (population stability, water conservation).

• Economic restructuring and industrial growth: Singapore aims to grow high-value, water-intensive industries (semiconductors, pharmaceuticals, petrochemicals, data centres) which require ultra-pure water for manufacturing and cooling.
• Domestic stability: Population growth is managed; per capita domestic water use has declined due to water conservation campaigns (e.g., "Make Every Drop Count"), water-efficient appliances (Mandatory Water Efficiency Labelling Scheme), and pricing.

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13. Figure 3: Energy Mix of Country X

(a) Coal [1]
Decreased from 50% to 25% = 25 percentage point decrease (largest).

(b) Combined renewable percentage in 2020: [1]
Marking: 1 mark for correct sum.

• Hydro (10%) + Solar (10%) + Wind (10%) + Other Renewables (0% — not listed in 2020, but if "Other Renewables" from 2000 is replaced by Solar/Wind, total renewables = 10+10+10 = 30%).
  Note: 2000 had "Other Renewables 5%"; 2020 shows Hydro 10%, Solar 10%, Wind 10% = 30%.

(c) Two advantages of the shift: [4]
Marking: 2 marks per advantage (1 for identification, 1 for explanation).

1. Reduced carbon emissions / climate change mitigation: Replacing coal (high CO₂) with solar/wind (near-zero operational emissions) significantly lowers greenhouse gas emissions, contributing to Paris Agreement targets.
2. Improved air quality and public health: Less coal/oil combustion reduces pollutants (SO₂, NOₓ, PM2.5), lowering respiratory/cardiovascular diseases and healthcare costs.
3. Energy security / reduced import dependence: Domestic renewables reduce reliance on imported fossil fuels, enhancing energy sovereignty and price stability.
4. Long-term cost competitiveness: As shown in Figure 8, LCOE of solar/wind has fallen below coal/gas in many regions, reducing electricity costs over time.

Any two well-explained = 4 marks.

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14. Sand as a Strategic Resource (Extract)

(a) One use: [1]
Accept any from extract: Concrete, glass, asphalt, land reclamation.

(b) Why desert sand is unsuitable: [2]
Marking: 1 mark for "rounded/smooth grains", 1 mark for "poor binding in concrete / lacks angularity".

• Desert sand grains are rounded and smooth due to wind erosion (aeolian transport), unlike river/marine sand which is angular.
• Angular grains interlock mechanically, providing strength in concrete; smooth grains act like ball bearings, weakening the bond with cement paste.

(c) Two environmental impacts of unregulated sand mining: [4]
Marking: 2 marks per impact (1 for identification from extract/knowledge, 1 for explanation).

1. Riverbank erosion and channel incision: Removing sand faster than replenishment lowers riverbed, steepens banks, causes collapse, threatens bridges, roads, and riverside communities.
2. Loss of biodiversity / habitat destruction: Mining destroys benthic habitats, spawning grounds for fish, and riparian vegetation; alters flow regimes and water turbidity.
3. Saline intrusion: Lowered riverbeds allow seawater to move upstream during high tides, contaminating freshwater intakes and agricultural land (mentioned in extract).
4. Groundwater depletion: Lowered riverbeds reduce baseflow recharge to adjacent aquifers, lowering water tables.
5. Increased flood risk (paradoxically): Channel incision can initially increase capacity but bank collapse adds sediment downstream, raising flood beds.

Any two well-explained = 4 marks.

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15. Figure 4: Circular Economy for E-Waste

(a) Design stage [1]
Eco-design and modularity are decided at the design phase to enable repair, upgrade, and recycling later.

(b) How material recovery contributes to resource sustainability: [3]
Marking: 1 mark for "recovers valuable materials", 1 mark for "reduces virgin extraction", 1 mark for "closes the loop / feeds back into manufacture".

• Recovers valuable finite materials (gold, silver, copper, rare earth elements, palladium) from discarded electronics.
• Reduces need for virgin mining, which causes habitat destruction, soil/water pollution, high energy use, and carbon emissions.
• Feeds secondary raw materials back into manufacturing (arrow to "Manufacture"), closing the loop and embodying circular economy principles.

(c) Reason for residual waste to landfill: [2]
Marking: 1 mark for valid reason, 1 mark for brief explanation.

• Technological limitations: Some materials (e.g., mixed plastics, composites, hazardous components like mercury in old screens) cannot be economically or safely recycled with current technology.
• Economic viability: Recycling certain low-value fractions costs more than the recovered material value, so they are landfilled.
• Contamination / improper sorting: E-waste mixed with general waste or contaminated (e.g., broken CFL lamps) may be diverted to landfill for safety.

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Section C: Extended Response Questions (12 marks)

16. Figure 5: Ecological Footprint vs Biocapacity

(a) Brazil [1]
Biocapacity (8.7) > Footprint (3.1) → ecological reserve.

(b) USA ecological deficit: [1]
Marking: 1 mark for correct calculation with units.

• Deficit = Footprint – Biocapacity = 8.1 – 3.6 = 4.5 global hectares per person (gha/person).

(c) Two reasons for USA > India footprint: [4]
Marking: 2 marks per reason (1 for factor, 1 for explanation linking to footprint components).

1. Higher per capita consumption / affluent lifestyle: USA has high income, leading to high energy use (transport, heating/cooling, appliances), high meat/dairy diet (large land/carbon footprint), high goods consumption (manufacturing footprint), and high waste generation — all increasing carbon, cropland, grazing, and built-up land footprints.
2. Energy system / carbon footprint: USA relies heavily on fossil fuels (oil, gas, coal) for transport and electricity; per capita CO₂ emissions ~14 t/yr vs India ~1.8 t/yr. Carbon footprint (forest land needed to sequester CO₂) is the largest component of ecological footprint.
3. Lower population density / land use patterns: USA's suburban sprawl, car-dependent infrastructure, and large per capita built-up land increase the built-up land footprint component.
4. Trade / imported biocapacity: USA imports biomass, timber, and food, outsourcing its footprint; but footprint accounting attributes this to the consumer (USA), while India is a net exporter of some agricultural products.

Any two well-explained = 4 marks.

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17. Figure 6: Terrace Farming Photograph

(a) How terrace farming modifies natural slope: [2]
Marking: 1 mark for "creates flat/level platforms", 1 mark for "following contour lines / stepped structure".

• Converts steep, continuous slopes into a series of flat or gently sloping, level platforms (terraces) that follow contour lines.
• Supported by retaining walls (stone/mud) to hold back soil, creating a stepped landscape that reduces effective slope gradient for cultivation.

(b) How terrace farming helps soil and water conservation: [4]
Marking: 2 marks for soil, 2 marks for water (or 1+1 per point, max 4).

Soil conservation:

• Reduces surface runoff velocity: Short slope lengths on each terrace reduce kinetic energy of water, minimising sheet and rill erosion.
• Traps sediment: Eroded soil from upper terraces is deposited on lower terraces rather than lost to rivers.
• Maintains soil depth and fertility on steep land that would otherwise be rapidly degraded.

Water conservation:

• Promotes infiltration: Level terraces allow rainwater to pond and infiltrate rather than run off, recharging soil moisture and groundwater.
• Enables irrigation control: Water can be directed, retained, and distributed evenly across paddies (especially for rice), improving water use efficiency.
• Reduces peak flows / flooding downstream by slowing watershed response.

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18. Figure 7: Water Withdrawal per Capita Choropleth Map

(a) One region with >1,000 m³/year: [1]
Accept: Central Asia (Turkmenistan, Uzbekistan, Kazakhstan), Middle East (e.g., UAE, Qatar, Saudi Arabia), North America (USA, Canada), Australia.

(b) Two reasons for high withdrawal in named region: [4]
Marking: 2 marks per reason (1 for identification, 1 for explanation). Contextualise to region chosen.

If Central Asia (e.g., Turkmenistan/Uzbekistan):

1. Extensive irrigation agriculture in arid climate: Cotton and wheat cultivation in desert environments (Aral Sea basin) requires massive irrigation withdrawals from Amu Darya/Syr Darya rivers; flood irrigation is inefficient (high evaporation).
2. Soviet-era legacy infrastructure: Old, leaky unlined canals and lack of water-saving technology (drip/sprinkler) lead to huge conveyance losses (>50% in some systems).

If Middle East:

1. Desalination-dependent supply with high per capita use: Wealth enables high domestic consumption (landscaping, pools, cooling) and low water tariffs; desalination allows withdrawal beyond renewable supply.
2. Agricultural policies for food security: Some countries (e.g., Saudi Arabia historically) used fossil groundwater for wheat/alfalfa in desert, with very high withdrawal per capita.

If USA/Canada:

1. High industrial and thermoelectric cooling withdrawal: Once-through cooling for power plants withdraws vast volumes (though much is returned); high industrial water use.
2. Irrigated agriculture in arid west: Large-scale irrigation (California Central Valley, High Plains Aquifer) for high-value crops.
3. High domestic per capita use: Lawn watering, pools, low pricing in some areas, large appliances.

Any two well-explained for the chosen region = 4 marks.

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19. Figure 8: LCOE of Energy Sources

(a) Solar PV [1]
Largest percentage decrease: from ~378 to ~49 USD/MWh ≈ 87% decrease. (Onshore wind: ~102 to ~33 ≈ 68% decrease.)

(b) Percentage decrease for Solar PV: [2]
Marking: 1 mark for working, 1 mark for answer.

• 2010: 378 USD/MWh
• 2022: 49 USD/MWh
• Decrease = 378 – 49 = 329
• % decrease = (329 / 378) × 100 ≈ 87.0% (accept 87% or ~87%)

(c) Two factors for falling solar PV cost: [3]
Marking: 1.5 marks per factor (1 for identification, 0.5 for brief explanation) or 1+1+1 for three distinct points.

1. Economies of scale / mass manufacturing: Massive expansion of production capacity (especially in China) reduced per-unit factory costs through learning-by-doing, automation, and supply chain optimisation.
2. Technological improvements: Higher cell efficiency (PERC, TOPCon, HJT), larger wafers, better anti-reflective coatings, diamond-wire sawing (less silicon waste) — more power per panel, lower $/W.
3. Balance-of-System (BoS) cost reductions: Cheaper inverters, mounting structures, cables, and faster installation methods reduced non-module costs.
4. **Policy-driven

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Secondary 3 Geography Quiz - Resources Sustainability (Answer Key)

Total Marks: 40

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Section A: Multiple Choice Questions (10 marks)

Question	Answer	Explanation
1	B	Renewable resources are naturally replenished at rates comparable to consumption (e.g., solar, wind, sustainably managed forests).
2	B	Carrying capacity is the maximum population an environment can sustain indefinitely without resource degradation.
3	D	Water stress occurs when annual supply falls below 1,000 m³/person (absolute scarcity) and when demand exceeds supply during a period.
4	B	Demand-side management reduces consumption (e.g., tiered pricing, water-saving devices). Options A, C, D are supply-side strategies.
5	B	Ecological footprint measures biologically productive land/water needed to support consumption and absorb waste.
6	B	Virtual water is the water embedded in production/trade of goods (e.g., 1 kg beef ≈ 15,000 L virtual water).
7	C	Natural gas is a fossil fuel (non-renewable). Solar, wind, biomass are renewable.
8	B	Circular economy keeps resources in use via reuse, repair, recycling — minimising waste and extraction.
9	B	Desalination requires high energy (often fossil fuels) and produces concentrated brine harmful to marine ecosystems.
10	D	Singapore's Four National Taps: (1) Local catchment, (2) Imported water, (3) NEWater, (4) Desalinated water. Groundwater extraction is not a tap.

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Section B: Structured Questions (18 marks)

11. Water Stress in Selected Countries (Figure 1)

(a) Qatar [1]
Highest baseline water stress at 4.97 (scale 0–5).

(b) 4.56 [1]
Jordan's baseline water stress percentage (extremely high >80%).

(c) Two physical factors: [4]

1. Arid climate / Low rainfall: Most countries are in hyper-arid zones (e.g., Arabian Peninsula, North Africa) with <100 mm annual rainfall, limiting natural recharge.
2. High evaporation rates: High temperatures year-round cause rapid evaporation of surface water and soil moisture, reducing effective water availability.
   Other acceptable: Limited perennial rivers; reliance on non-renewable fossil aquifers; saline groundwater.

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12. Singapore Water Demand Projection (Figure 2)

(a) Trend: Total water demand doubles from ~430 mgd (2020) to ~660 mgd (2060), driven entirely by non-domestic sector growth. Domestic demand remains stable (~210→230 mgd). [2]

(b) Calculation: [2]

• 2020 non-domestic: ~210 mgd
• 2060 non-domestic: ~430 mgd
• Increase = 430 – 210 = 220 mgd
• % increase = (220 / 210) × 100 ≈ 104.8% (accept 100–105%)

(c) Reason for non-domestic growth: [3]
Economic restructuring toward high-value, water-intensive industries (semiconductors, pharmaceuticals, petrochemicals, data centres) which require ultra-pure water for manufacturing/cooling. Domestic stability due to water conservation (mandatory water-efficient fittings, pricing) and slower population growth.

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13. Energy Mix of Country X (Figure 3)

(a) Coal [1]
Decreased from 50% (2000) to 25% (2020) — a 25 percentage-point drop (largest).

(b) Combined renewables in 2020: Hydro (10%) + Solar (10%) + Wind (10%) + Other Renewables (5%) = 35% [1]

(c) Two advantages of the shift: [4]

1. Reduced carbon emissions: Replacing coal/oil with renewables/natural gas lowers CO₂ per unit energy, mitigating climate change.
2. Energy security & diversification: Less reliance on imported fossil fuels; domestic renewables (solar/wind/hydro) enhance resilience to price shocks and supply disruptions.
   Other acceptable: Reduced air pollution (SO₂, NOₓ, PM); job creation in green energy; compliance with international climate commitments.

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14. Sand as a Strategic Resource (Extract)

(a) One use: Concrete / glass / asphalt / land reclamation [1]
(Any one from extract.)

(b) Why desert sand is unsuitable: [2]
Desert sand grains are rounded and polished by wind abrasion, lacking the angularity and surface roughness needed for binding in concrete/asphalt. River/marine sand has angular grains that interlock mechanically.

(c) Two environmental impacts of unregulated sand mining: [4]

1. Riverbank/coastal erosion: Removal of sand lowers riverbeds/coastal profiles, undercutting banks and accelerating erosion, threatening infrastructure and habitats.
2. Saline intrusion: Lowered riverbeds allow seawater to penetrate further upstream during high tides, contaminating freshwater aquifers and agricultural land.
   Other acceptable: Loss of aquatic biodiversity (spawning grounds, benthic habitats); increased flooding risk; land subsidence.

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15. Circular Economy for E-Waste (Figure 4)

(a) Design stage [1]
Eco-design (modularity, durability, recyclability) is decided at design phase.

(b) Material recovery contribution to sustainability: [3]
Recovers valuable metals (gold, copper, rare earths) and plastics from e-waste, reducing virgin resource extraction, lowering energy use (recycling Al uses 95% less energy than primary production), and preventing toxic leaching (lead, mercury) from landfills.

(c) Reason for residual waste to landfill: [2]
Technological/economic limits: Some components (e.g., mixed plastics, contaminated fractions, hazardous materials like mercury in lamps) cannot be economically or safely recycled with current technology, requiring secure landfill disposal.

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Section C: Extended Response Questions (12 marks)

16. Ecological Footprint vs Biocapacity (Figure 5)

(a) Brazil [1]
Biocapacity (8.7 gha) > Footprint (3.1 gha) → ecological reserve.

(b) USA ecological deficit: 8.1 – 3.6 = 4.5 global hectares per person [1]

(c) Two reasons for USA's larger footprint vs India: [4]

1. Higher per capita consumption: USA has high-energy lifestyles (large homes, car dependence, meat-rich diets, high goods turnover) requiring more bioproductive land for energy, food, and waste absorption.
2. Carbon footprint dominance: USA's footprint is ~60% carbon (energy/transport), while India's is lower due to less fossil fuel use per capita and more plant-based diets.
   Other acceptable: USA imports biocapacity via trade (embedded land in goods); India's lower industrialisation and higher population density reduce per capita demand.

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17. Terrace Farming (Figure 6)

(a) Modification of natural slope: [2]
Steep slopes are converted into level, stepped platforms (terraces) following contour lines, supported by stone/earth risers. This transforms continuous steep gradients into a series of flat or gently sloping cultivable surfaces.

(b) Soil and water conservation: [4]

1. Reduces surface runoff velocity: Terraces shorten slope length and gradient, slowing water flow, allowing infiltration, and reducing erosive power.
2. Traps sediment and nutrients: Risers act as barriers, capturing eroded topsoil and organic matter on each terrace, maintaining soil fertility.
   Additional: Enables irrigation control (ponding water for rice); reduces landslide risk by stabilising slopes.

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18. Integrated Resource Management (Synthesis)

Evaluate the view that technological solutions alone can achieve resource sustainability. [6]

Level 3 (5–6 marks): Balanced evaluation with specific examples. Recognises technology's role (efficiency, substitution, monitoring) but argues institutional, behavioural, and economic factors are equally critical. Cites cases (e.g., Singapore's water tech + pricing + governance; Jevons paradox; e-waste recycling limits).

Level 2 (3–4 marks): Describes technological solutions (desalination, renewables, recycling) and mentions some limitations (cost, energy, equity) but lacks structured evaluation.

Level 1 (1–2 marks): Lists technologies or states opinion without evidence.

Key points for high marks:

• Technology enables (NEWater, solar PV, precision agriculture, circular design).
• But fails without:
  • Governance (regulation, pricing, property rights — e.g., sand mining bans).
  • Behavioural change (conservation culture, diet shifts).
  • Equity & access (tech may exclude poor; virtual water trade shifts burden).
  • Systemic limits (rebound effects, thermodynamic constraints, planetary boundaries).
• Conclusion: Technology is necessary but insufficient; integrated policy-society-tech approaches required.

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Marking Summary

Section	Marks
A (MCQ)	10
B (Structured)	18
C (Extended)	12
Total	40

End of Answer Key