Analyse environmental data and technology
Calculate and present environmental data, assess uncertainty and evaluate technology including geospatial systems, sensors and big data.
Exam scope and assessment notes
Original StudyForA teaching and practice, not Cambridge-authored questions, mark schemes or official grades. Cambridge expects candidates to study all eight topics, carry out investigative work and learn teacher-selected case studies. This course does not replace a centre's named case-study examples, current local environmental data, supervised fieldwork or the candidate's own investigation. Practice datasets are illustrative, not observations from a real place. No official assessment or certification is provided. The examples and practice datasets in these lessons are fictional and formative; learners must add their centre's verified case studies and current local evidence.
Before you begin
- Cambridge recommends prior environmental/science study equivalent to IGCSE or O Level. This is an AS-only qualification; use the exam-year syllabus and confirm centre entry details.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What makes environmental evidence useful?
What you will learn
- Choose a table, map or graph appropriate to the variables
- Calculate percentages, rates and population estimates with units
- Evaluate data quality and the benefits and limits of technology
Calculate and present clearly
Use line graphs for ordered change, bar charts for categories and scatter graphs for paired variables. Label axes, units, dates, sample sizes and sources; keep original data so another person can check the calculation.
Percentage change = change ÷ original value × 100. For biodiversity, Simpson's index of diversity is D = 1 − Σ[n(n−1)] ÷ [N(N−1)]; use the formula supplied in the question paper, where n is the count of each type and N is the total. Quadrat data can also give percentage cover, frequency and an abundance estimate. Check the denominator, units, rounding and graph scale.
Technology expands coverage but not certainty
Geospatial systems, satellite sensors, radio tracking, computer modelling and crowdsourcing can gather or analyse data at wide scales. Big data describes datasets whose amount and type, generation speed or uses create opportunities and analytical challenges.
Benefits include coverage, speed and the ability to combine sources; limitations include trustworthiness, missing data, resolution, bias, privacy, processing assumptions and access. Evaluate the amount and type of stored data, how quickly new data appear, whether they are reliable and what decisions they can support. Validate findings with suitable ground evidence or independent methods.
Sources for this lesson
Pause and explain
What does positive correlation establish?
Worked example
A reserve's tree-cover measure rises from 240 ha to 300 ha over five years. Calculate percentage and mean annual increase.
Show the worked solution
- Calculate the change from the original amount.
- Divide by the original value and multiply by 100.
- Divide the change by five years and qualify the average.
Answer The increase is 60 ha. Percentage increase = 60/240×100 = 25%. Mean annual increase = 60/5 = 12 ha per year, assuming a simple average; it does not show whether gains were steady each year.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Household water use falls from 180 L per person per day to 153 L. Calculate the percentage decrease.
Give me a hint
Divide the reduction by the original amount.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply choose a table, map or graph appropriate to the variables to the stated context.
- Explain the inference and one limitation or trade-off.
The reduction is 27 L. Percentage decrease = 27/180×100 = 15%. Use the original value as the denominator and report a percentage rather than a volume.
Look for these in your work
- Choose a table, map or graph appropriate to the variables
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
Satellite images suggest forest cover fell, but cloud cover differs between dates. What should be checked?
Give me a hint
The two images may not be directly comparable.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply calculate percentages, rates and population estimates with units to the stated context.
- Explain the inference and one limitation or trade-off.
Check season, resolution, cloud masking and classification method. Quantify usable area and uncertainty, then corroborate with another image or ground evidence before concluding that forest cover declined.
Look for these in your work
- Calculate percentages, rates and population estimates with units
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
A sample contains 6 individuals of species A, 4 of species B and 2 of species C. Use the supplied formula D = 1 − Σ[n(n−1)]/[N(N−1)] to calculate Simpson's index of diversity.
Give me a hint
Find N first, then calculate each species term inside the sum.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply evaluate data quality and the benefits and limits of technology to the stated context.
- Explain the inference and one limitation or trade-off.
N = 6 + 4 + 2 = 12. Σ[n(n−1)] = 6×5 + 4×3 + 2×1 = 44. D = 1 − 44/(12×11) = 1 − 44/132 ≈ 0.667. Use the version of the formula supplied by the question paper and keep the total N consistent with the sample.
Look for these in your work
- Evaluate data quality and the benefits and limits of technology
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
Common mistakes
- Using the final rather than original value as the percentage denominator
- Treating satellite resolution as proof of accuracy
- Inferring cause from a scatter-graph association
What can you explain now?
What does positive correlation establish?
Compare with the explanation
An association in the measured sample, not necessarily a cause
Other variables, sampling bias or reverse causation may explain the pattern.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Which denominator should be used when calculating percentage change?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.