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Edexcel IGCSE Geography · Hazardous Environments
Hazardous Enquiry Skills
The big idea: A good geography enquiry follows a chain — collect the right data (primary + secondary),
present it clearly with the right graph or map, analyse it using statistics like the mean,
reach a conclusion that answers your original question, and then honestly evaluate how reliable it all was.
Summary — What This Chapter Covers
Data presentation — choosing the right graph (line, bar, rose, scattergraph) or map (isoline, sample site) for different types of weather data.
Primary vs secondary data — primary is data you collect yourself; secondary is data from other sources like the Met Office or OS maps.
Completing graphs accurately — plotting missing bars/points to match the existing style exactly.
Spotting anomalies — identifying results that don't fit the pattern and explaining why they might have occurred.
Analysing data statistically — calculating the mean, and understanding why it's used.
Qualitative analysis — using annotated photographs and field sketches to interpret microclimates.
Reaching a conclusion — linking findings back to the original hypothesis and explaining anomalies.
Evaluating an enquiry — judging reliability, accuracy, and what you'd improve next time.
1. Weather Enquiry Data Presentation
Primary Data — Choosing the Right Graph
Once you've collected primary data out in the field (like temperature, wind speed, or rainfall readings),
you need to present it in a way that makes patterns easy to see. The trick is that different graphs
suit different types of data — picking the wrong one loses you marks even if your numbers are correct.
Think of it like choosing the right tool for a job: you wouldn't use a hammer to turn a screw, and you
shouldn't use a line graph to show wind direction.
Which graph for which data?
Graph Type
Best Used For
Line graph
Changes in temperature — either spatially (across a distance) or over time
Bar graph
Precipitation, wind speed (discrete values at different sample points)
Rose graph
Wind direction and speed together (a compass-style graph)
Scattergraph
The relationship between two variables, e.g. air pressure vs precipitation
Data can also be shown on maps — for example, marking exactly where each sample site was located,
or drawing isoline maps, which are maps with lines joining points of equal value (a bit like contour
lines on an OS map, but for temperature or precipitation instead of height). Every point on the same isoline
has the same reading.
Worked Example — Completing a Bar Graph
Five wind speed samples were collected: 50.1, 35.1, 45.1, 40.0, and 10.0 mph. Samples 2, 3 and 5 were already
plotted on the bar graph. To complete it for samples 1 and 4:
Bar 1 (50.1 mph) → drawn just above the 50 mph gridline, matching the width of the other bars.
Bar 4 (40.0 mph) → drawn exactly on the 40 mph gridline.
The bars don't need shading, but they must be the same width as the existing bars — consistency is what
examiners are checking for.
Practice Question 1
Why is it important to use the same bar width and style when completing a graph, rather than just placing the bar at roughly the right height?
Spotting & Explaining Anomalies
An anomaly is a result that doesn't fit the general pattern of the rest of the data — it stands
out as unusually high or low compared to its neighbours. Spotting one is only half the task; you also need to
be able to explain why it might have happened.
Common causes of anomalies
Human error with equipment — misreading a dial, using it incorrectly
Sheltered location — e.g. a wind speed reading taken behind a building would be much lower than expected
Timing variation — if readings weren't all taken at exactly the same time, natural changes in weather conditions could cause one reading to differ
Worked Example — Identifying the Anomaly
Using the wind speed data (50.1, 35.1, 45.1, 40.0, 10.0 mph), Sample 5 (10.0 mph) is the anomaly — it's far
lower than the general pattern of 35–50 mph shown by the other four readings. A good explanation:
"The reading may have been taken in a sheltered area, such as behind a building, which reduced the wind
speed reaching the instrument."
Practice Question 2
A student records temperature readings of 18°C, 19°C, 18.5°C, 27°C and 19°C across five sample sites in a park. Identify the anomaly and suggest one possible explanation.
2. Secondary Data
A strong enquiry never relies on primary data alone — it also uses secondary data: information
that was collected by someone else, which you use to add context, check your results, or plan your investigation
in the first place.
Useful secondary sources for a weather enquiry
Met Office data — official weather station records
Newspaper articles / websites — reports about a specific weather event
Ordnance Survey (OS) maps — used to identify and justify sample site locations, and to check altitude
Aerial photographs — show the wider landscape context of a site
Why it matters: the mark scheme for secondary sources usually awards marks in two parts —
one for correctly naming a source (e.g. "OS map"), and a second for explaining its purpose
(e.g. "gives the altitude of the site"). Naming a source alone often only gets you half the marks available!
Practice Question 3
Describe two sources of secondary information that might be useful when planning a microclimate investigation. (4 marks)
3. Analysing & Interpreting Data
Calculating the Mean
Once weather data has been collected and presented, it needs to be analysed — turned into a
conclusion. Because temperature, precipitation, and wind speed are all quantitative (numerical) data,
they're usually analysed using statistical methods. The most common one you'll be asked to use is the
mean (the mathematical average).
Formula: The Mean
Mean = (sum of all values) ÷ (number of values)
In plain words: add up every single reading, then divide by how many readings there are.
Worked Example — Calculating the Mean Wind Speed
Wind speeds: 50.1, 35.1, 45.1, 40.0, 10.0 mph
Step 1 — Add all the values together:
50.1 + 35.1 + 45.1 + 40.0 + 10.0 = 180.3
Step 2 — Divide by the number of values (5):
180.3 ÷ 5 = 36.06
Step 3 — Round to one decimal place (as the question asked):
Mean wind speed = 36.1 mph
Rounding rule you MUST know: Look at the digit immediately after the decimal place you're
rounding to.
If it's 5 or higher → round up. (10.15 → 10.2)
If it's 4 or lower → round down. (10.13 → 10.1)
Always show your working in full — the addition step is usually worth its own mark, separate
from the final rounded answer.
Practice Question 4
A student records five temperature readings: 14.2°C, 15.8°C, 13.9°C, 16.0°C, 14.6°C. Calculate the mean temperature, giving your answer to one decimal place. Show your working. (2 marks)
Analysing Photographs & Field Sketches
Not all analysis is number-based. Photographs and field sketches are used for qualitative analysis —
interpreting what you can see rather than measure. In a weather/microclimate enquiry, annotated
photographs can be used to explain:
Different aspects of a microclimate (e.g. why one area is warmer or windier than another)
Weather conditions during or after a specific weather event
The data collection techniques used at a site
Worked Example — Annotating a Microclimate Photo
A photo of a university campus could be annotated to explain local temperature/wind variations:
"Tall buildings on either side funnel the wind" (explains a wind speed anomaly)
"Heat loss from the buildings from heating increases the temperature" (explains a warm spot)
"Access road has higher temperatures due to dark tarmac absorbing heat from the sun"
"Grass areas — higher humidity due to transpiration"
Notice how each annotation links a visible feature directly to a geographical process — that link
is what earns marks, not just describing what's in the photo.
4. Conclusion
Once your data is analysed, you draw everything together into a conclusion. This isn't just
a summary — it should directly answer the enquiry question you set out to investigate.
A strong conclusion should:
State clearly whether the original hypothesis has been proven or disproved
Identify and explain any anomalies in the data (e.g. an unexpected spike in wind speed or temperature at one location)
Suggest a cause for those anomalies — either a natural cause (e.g. shelter, aspect) or human/recording error
Practice Question 5
A student hypothesised that "temperature decreases with distance from the town centre." Their data mostly supported this, except for one reading in a park that was much lower than expected. How should this be addressed in the conclusion?
5. Evaluation
The final stage of any enquiry is evaluation — honestly reflecting on how successful the
investigation was, and what you'd do differently if you repeated it. This is often the highest-mark question
in the exam (commonly worth 8 marks), so it deserves real depth, not a quick "it went well."
What a full evaluation must cover
Equipment issues — Was any equipment faulty? Were measurements misread? How did this affect your ability to answer the enquiry question?
Enquiry design issues — Were the sampling method and number of sample sites appropriate? Would a different technique or extra equipment have improved things?
Analysis method issues — Was the mean (or another method) the right choice? Were there better alternatives available?
A final judgement — an overall verdict on how successful the data analysis was in reaching a reliable conclusion.
Reliability — could the enquiry be repeated and get the same results?
Common mistake: Students often list problems ("the equipment was faulty," "we only had 5 sample
sites") but forget to explain how each issue actually affected the ability to answer the enquiry
question, and never give a final overall judgement. Both of these are needed for top marks — description
alone isn't evaluation.
Practice Question 6
Evaluate how successful your chosen data collection methods were in answering your geographical enquiry question. (8 marks) — Outline the structure your answer should follow.
What to Memorise
Primary Data
Data you collect yourself, first-hand, out in the field (e.g. your own wind speed readings).
Secondary Data
Data collected by someone else that you use to support your enquiry (e.g. Met Office records, OS maps).
Isoline Map
A map with lines connecting points of equal value — used for temperature or precipitation, similar to contour lines for height.
Anomaly
A result that doesn't fit the general pattern of the rest of the data set; usually caused by human error, shelter/exposure, or timing differences.
Mean
The mathematical average: add all values together, then divide by the number of values.
Qualitative Analysis
Analysis based on descriptive, non-numerical evidence — e.g. interpreting annotated photographs or field sketches.
Hypothesis
A testable statement predicting a relationship (e.g. "temperature decreases with distance from town centre") that the enquiry's conclusion should prove or disprove.
Evaluation
A reflective judgement on the success, accuracy, and reliability of an enquiry, including what could be improved if repeated.
Concepts Checklist
Exam Tips
You won't be asked to draw a whole graph from scratch. It's far more common to be given a
partially-completed graph and asked to add the missing bars/points using provided data. Take your time and
match the exact style already used (bar width, connected lines, etc.).
Don't forget to show your working for the mean. The addition step and the final rounded
answer are usually marked as two separate points — jumping straight to a final number without showing your
sum can lose you a mark even if the answer is correct.
Naming a secondary source isn't enough on its own. Always explain what it's used for
— e.g. not just "OS map" but "OS map — used to find the altitude of the site."
For the big 8-mark evaluation question, examiners want to see: what went well and how you
know your results were accurate; whether the enquiry is reliable and repeatable; what could be improved;
and what you'd do differently next time. Structure your answer around these four questions.
Rounding reminder: 5 or higher → round up. 4 or lower → round down. Always double-check the
number of decimal places the question asks for.