Cambridge IGCSE Environmental Management: Water — Practice Questions (0680)

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs — Cambridge International holds copyright in its own papers. Use these alongside the official past papers available free from your board.

Related: Water study guide and revision notes

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Section A

1. Name the four stages of water treatment. [4]

2. State the key difference between bioaccumulation and biomagnification. [2]

3. Name the vector responsible for spreading malaria. [1]

Section B

4. A coastal region builds a desalination plant using reverse osmosis to supplement its potable water supply.

(a) Briefly describe how reverse osmosis desalination works. [2] (b) Discuss one benefit and one limitation of using desalination as a water source. [4]

5. Agricultural fertiliser runoff enters a lake, and over the following weeks the lake develops a thick algal bloom, and fish begin dying.

(a) Name the process being described. [1] (b) Explain, as a causal chain, how the fertiliser runoff leads to the fish dying. [4]

6. A government is comparing strategies to control malaria and cholera in a rural region.

(a) State one control strategy specific to malaria and one specific to cholera. [2] (b) Explain why these two diseases require different control strategies. [3]

7. A country builds a new multipurpose dam on a major river.

(a) State two uses of the dam from the list covered in this topic. [2] (b) For one use named, state a corresponding limitation. [2]

8. Overfishing has severely depleted wild fish stocks in a coastal fishing community, which turns to marine aquaculture as an alternative.

(a) Define marine aquaculture. [2] (b) Explain why this shift could help address the underlying problem of overfishing. [3]

9. Explain the difference between a “store” and a “transfer” in the water cycle, giving one example of each. [4]

10. Explain four causes of water scarcity and two strategies for managing water supply sustainably. [8]

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Answers

1. Screening, sedimentation, filtration, chlorination [4].

2. Bioaccumulation is a toxin building up within a single organism over time; biomagnification is that concentration increasing further as it passes up a food chain from prey to predator [2].

3. The female Anopheles mosquito [1].

4. (a) Reverse osmosis forces salt water through a semi-permeable membrane under pressure, which allows water molecules through while blocking salt and other dissolved substances, producing fresh water on the other side [2]. (b) Benefit: desalination provides a water source independent of rainfall, increasing water security in regions with limited fresh water availability [1–2]. Limitation: desalination requires significant energy input, making it costly to operate and potentially environmentally impactful depending on the energy source used [1–2].

5. (a) Eutrophication [1]. (b) Fertiliser runoff introduces excess nutrients into the lake (nutrient enrichment) [1], which causes rapid, excessive growth of algae on the water’s surface (an algal bloom) [1]. The dense algal bloom blocks sunlight from reaching plants below the surface, and as the algae eventually die and decompose, the decomposition process consumes dissolved oxygen in the water [1], depleting oxygen levels to the point where fish and other aquatic organisms cannot survive [1].

6. (a) Malaria: personal protection (such as bed nets) or vector control (such as insecticide spraying) [1]. Cholera: sanitation, safe potable water supply, or vaccination [1]. (b) Malaria is a vector-borne disease transmitted by mosquitoes, so its control strategies target the mosquito vector and prevent bites [1–2]. Cholera is a waterborne disease spread through contaminated water and poor sanitation, so its control strategies instead target water quality and hygiene rather than an insect vector — the two diseases spread by entirely different mechanisms and therefore require different control approaches [1].

7. (a) Any two of: flood control, hydro-electric power, irrigation, storage, transport, recreation, tourism, fish farming [2]. (b) For example, hydro-electric power provides a renewable energy source, but the dam’s construction can disrupt river ecosystems and displace communities living in the area flooded by the reservoir upstream of the dam [2]. (Any correctly paired use-and-limitation combination from the syllabus gains full credit.)

8. (a) Marine aquaculture is the farming of marine species, such as fish, crustaceans or seaweeds, in captivity, rather than harvesting them from the wild [2]. (b) Farming marine species in captivity reduces the community’s dependence on catching wild fish directly from already-depleted stocks [1–2], allowing wild populations a greater opportunity to recover over time while the community’s demand for seafood continues to be met through farmed sources instead [1–2].

9. A store is a place where water is held for a period of time, such as ice sheets/glaciers, the oceans, or ground water [2]. A transfer is the movement of water from one store to another, such as precipitation (water moving from the atmosphere to the surface) or evaporation (water moving from a surface store to the atmosphere) [2].

10. Causes, any four, 1 mark each: population growth and urbanisation raise demand faster than supply can be developed [1]; agriculture, which accounts for around 70% of freshwater use, often through inefficient flood irrigation [1]; pollution of rivers and aquifers by industry, sewage and agricultural runoff, which removes usable supply [1]; over-abstraction of groundwater faster than aquifers recharge, causing water tables to fall [1]. Strategies, 2 marks each: drip irrigation and lining canals deliver water directly to plant roots and cut losses to evaporation and seepage, greatly increasing agricultural efficiency [1] [1]. Rainwater harvesting and greywater recycling capture water that would otherwise be lost and reduce demand on mains supply [1] [1]. (Also accept: metering and pricing to reduce waste; desalination; repairing leaking pipes; treating and reusing wastewater.)

A note on exam technique for this topic

Question 7 illustrates the study guide’s core advice for multipurpose dam questions: use the full list of named uses as a structure, pairing each benefit named with its corresponding documented limitation, rather than only listing benefits. Question 6 rewards keeping malaria and cholera control strategies strictly separate by transmission mechanism — vector control belongs to malaria, sanitation-based measures belong to cholera — since mixing the two up is the most common error the study guide flags for this sub-topic. Question 9 rewards the same store-versus-transfer discipline the study guide recommends for revising the water cycle: learning both as two separate, linked lists, rather than trying to hold the whole cycle as a single undifferentiated diagram.