These eight questions use original, fictional data on extraction and its management. They follow the lessons in effects and management of resource extraction.
Write your own answer, then open the explanation.
Questions
Question 1: A fictional gravel pit deepens a river channel from 1.8 m to 2.7 m. Bank retreat rises from 0.5 m a year to 1.5 m a year. Find the change in depth and how many times faster the bank retreats.
Answer
Depth change = 2.7 − 1.8 = 0.9 m.
Retreat ratio = 1.5 ÷ 0.5 = 3 times as fast.
Question 2: Using Question 1, write a three-link effect chain from gravel removal to loss of a footpath 4 m from the bank. Tag each link as supported or assumed.
Answer
- Gravel removal deepens the channel. Supported: 1.8 m to 2.7 m.
- The bank retreats faster. Supported: 0.5 to 1.5 m a year.
- The footpath is lost. Supported as a risk: at 1.5 m a year, 4 m lasts about 2.7 years (4 ÷ 1.5), but no loss is recorded.
Question 3: A company plants 5 000 mangrove seedlings and spends RM60 000. After two years 3 500 are alive. Find the survival rate and say whether the figures show that coastal erosion was reduced.
Answer
Survival = 3 500 ÷ 5 000 = 70%.
No. The planting count, the spend and the survival rate measure effort and the action still in place. Erosion measured before and after is the evidence of effect, and it is not given.
Question 4: Turbidity in a stream was 80 units before a silt pond was built and 52 units after. The year after was drier. Calculate the percentage fall and write a cautious verdict.
Answer
Fall = 80 − 52 = 28 units, and 28 ÷ 80 = 35%.
Verdict: “Turbidity fell 35% after the pond was built, but the following year was drier, so some of the fall may be due to rainfall. A comparison with a stream without a pond would be needed.”
Question 5: A proposal would ban fishing in a fictional 8 000 m² reef zone for one year. Count squares of 1 m² contained 14, 18, 16 and 12 fish. Estimate the total fish and state the main limitation.
Answer
Mean = (14 + 18 + 16 + 12) ÷ 4 = 60 ÷ 4 = 15 per m². Estimate = 15 × 8 000 = 120 000 fish.
Limitation: four squares cover 4 m² of 8 000 m², which is 0.05%, so the estimate may not represent the whole zone.
Question 6: In Question 5, 30 families fish in the zone. Give one effect of the ban on them and one piece of evidence you would want before judging the ban.
Answer
The 30 families lose access to the zone for a year, so their income from it falls unless they fish elsewhere.
Evidence wanted: how much of each family’s income comes from the zone, and whether nearby areas can absorb the fishing effort.
Question 7: A fictional 50 ha site is proposed for 750 homes or a 50 ha oil palm plot. Facts given: the site drains into a village stream; no soil or price data are supplied. Calculate housing density and name two missing facts.
Answer
Density = 750 ÷ 50 = 15 homes per hectare.
Missing facts: soil quality (so palm yield cannot be judged) and cost or price (so the uses cannot be compared financially). The stream is a supplied fact that affects both uses.
Question 8: Write a three-sentence recommendation for the site in Question 7 that uses only supplied facts.
Answer
Model answer: “Housing would provide 750 homes at 15 per hectare, whereas oil palm would use the whole 50 ha. Both uses would sit beside the stream that drains into the village, so a protected strip along the stream is sensible. Soil and price data are not given, so neither use can be confirmed as best, and the most cautious recommendation keeps the stream strip free of building and planting.”
If you got these wrong
Questions 1 and 2 test tracing an environmental effect. Questions 3 and 4 test separating a mitigation action from evidence that it worked. Questions 5 and 6 test evaluating a conservation proposal, and Questions 7 and 8 test competing land-use needs.
Build a timed set with the timed original practice session builder and keep a mistake log. To go through your errors with a teacher, see online one-to-one Geography tuition.