To compare impacts fairly, put both events in one sentence with figures, use a rate when the populations differ, and say what the evidence cannot show. The skill uses data from a supplied case, so the facts come from the question.
This lesson builds on exposure and physical events. For recording evidence with source and date, see the Geography evidence and case-study ledger.
How do you compare step by step?
- Read the source line for date, place and who gathered the data.
- Pick the measures: deaths, injuries, homes damaged, people affected, cost.
- Work out a rate for fairness, for example per 100,000 people affected.
- Write comparing sentences with a figure for each place.
- Add a cautious reason and say what extra evidence would help.
Worked example
The data below are invented for practice. Treat them as supplied case evidence.
| Event X | Event Y | |
|---|---|---|
| Magnitude | 7.1 | 6.4 |
| People affected | 600,000 | 450,000 |
| Deaths | 120 | 18 |
| Homes destroyed | 4,500 | 900 |
Step 1, totals: Event X had 120 ÷ 18 ≈ 6.7 times as many deaths, and 4,500 ÷ 900 = 5 times as many homes destroyed.
Step 2, rates: deaths per 100,000 affected. X: 120 ÷ 600,000 × 100,000 = 20. Y: 18 ÷ 450,000 × 100,000 = 4.
Step 3, sentence: “Event X caused 120 deaths against 18 for Event Y, which is a rate of 20 per 100,000 affected compared with 4.”
Step 4, reason with care: X was the larger event, which may explain part of the gap. The table does not give building types or warning time, so the data cannot confirm other causes.
The mistake to watch for
A common slip is to describe each event separately and stop at totals.
Mistaken answer: “Event X had 120 deaths. Event Y had 18 deaths. They are different.”
There is no comparing word, no rate and no reason.
The correction is to join the figures in one sentence, add the rate, and give a reason that stays inside the evidence. Avoid claiming a cause the table does not mention.
Check yourself
Use the table above.
1. Calculate the deaths in Event Y as a percentage of people affected.
Show answer
18 ÷ 450,000 = 0.00004, so 0.004%. A rate per 100,000 (4) is easier to read for such a small share.
2. Write one comparing sentence about homes destroyed.
Show answer
“Event X destroyed 4,500 homes, five times as many as Event Y with 900.”
3. Name one piece of extra evidence that would help explain the gap.
Show answer
Examples: building types in each area, depth of the earthquake, or the time between warning and impact. Any item must link to the impact.
Where this leads next
Next, separate a classroom hazard model from emergency guidance. For wider practice with evidence, the module on case-study reasoning extends this lesson.
If you need help turning two tables into a tight paragraph, online one-to-one Geography tuition lets a teacher respond to your own wording.