Flood management and uncertainty
Original practice assessment. The teacher can edit this pack; edits may change its mark total or invalidate its guidance.
A storm, its hydrograph and flood management
Original fictional unfamiliar-resource pack. Work across the resources; each describes the same teaching scenario. This is not an official examination paper or a real project forecast.
Options
Upstream storage and wetland restoration: £4.2 million
May attenuate peak flow and provide habitat
Land agreements and maintenance are required; storage may fill in extreme events
Town flood wall: £7.5 million
Protects selected assets up to its design conditions
Overtopping and downstream consequences remain possible
Property adaptation and warnings: £3.1 million
Reduces some damage and improves preparation
Does not stop floods or secure all transport links
Stakeholder evidence
Town resident: Our road and homes need protection.
Downstream resident: Reducing risk in the town must not increase our risk.
Upstream farmer: Storage on my land needs an agreed payment and responsibilities.
One fictional storm record
Scroll the diagram sideways to see the full resource.
| Hour | Rainfall in preceding hour (mm) | Discharge (m³/s) |
|---|---|---|
| 0 | 0 | 5 |
| 1 | 4 | 5 |
| 2 | 11 | 5 |
| 3 | 6 | 5 |
| 4 | 0 | 11 |
| 5 | 0 | 17 |
| 6 | 0 | 23 |
| 7 | 0 | 29 |
| 8 | 0 | 23 |
| 9 | 0 | 17 |
| 10 | 0 | 11 |
| 11 | 0 | 5 |
| 12 | 0 | 5 |
Resource description
Hour 0: 0 mm rainfall, 5 m³/s discharge; Hour 1: 4 mm rainfall, 5 m³/s discharge; Hour 2: 11 mm rainfall, 5 m³/s discharge; Hour 3: 6 mm rainfall, 5 m³/s discharge; Hour 4: 0 mm rainfall, 11 m³/s discharge; Hour 5: 0 mm rainfall, 17 m³/s discharge; Hour 6: 0 mm rainfall, 23 m³/s discharge; Hour 7: 0 mm rainfall, 29 m³/s discharge; Hour 8: 0 mm rainfall, 23 m³/s discharge; Hour 9: 0 mm rainfall, 17 m³/s discharge; Hour 10: 0 mm rainfall, 11 m³/s discharge; Hour 11: 0 mm rainfall, 5 m³/s discharge; Hour 12: 0 mm rainfall, 5 m³/s discharge
Land cover and homes
| Reach | Impermeable surface (%) | Homes | Homes in mapped flood extent (%) |
|---|---|---|---|
| Upper reach | 20 | 900 | 20 |
| Town reach | 65 | 1900 | 50 |
| Lower reach | 35 | 1700 | 30 |
Resource description
The extent is one scenario footprint. It is not an annual probability map or a map of all future floods.
Management alternatives
| Option | Capital cost (£ million) | Benefit | Limitation |
|---|---|---|---|
| Upstream storage and wetland restoration | 4.2 | May attenuate peak flow and provide habitat | Land agreements and maintenance are required; storage may fill in extreme events |
| Town flood wall | 7.5 | Protects selected assets up to its design conditions | Overtopping and downstream consequences remain possible |
| Property adaptation and warnings | 3.1 | Reduces some damage and improves preparation | Does not stop floods or secure all transport links |
Resource description
Available capital budget: £8 million. Options are alternatives; their benefits cannot simply be added. Operating costs are separate.
Resource limits: Peak and lag describe one synthetic storm.; Surface cover alone does not establish discharge or annual flood risk.
1 mark1. What is peak discharge in m³/s?
1 mark2. What is the peak lag time in hours?
1 mark3. What can this record establish?
- The discharge peak follows the rainfall peak in this storm.
- The same lag occurs in every storm.
- The lag proves that one particular soil type caused the response.
1 mark4. Calculate homes in the mapped extent at the town reach.
4 marks5. Explain one way impermeable surfaces may affect the storm response, and one reason this record cannot isolate their effect.
9 marks6. Recommend an option for a storm, its hydrograph and flood management. Use at least two resources, compare an alternative and address an uncertainty or stakeholder concern.
Supplementary geographical skill: Choropleth maps
The shading represents a percentage of households, not a total. Class boundaries are lower-inclusive and upper-exclusive.
Scroll the diagram sideways to see the full resource.
| District | Reported damage (%) | Households |
|---|---|---|
| A | 2 | 1000 |
| B | 17 | 500 |
| C | 21 | 500 |
| D | 38 | 100 |
Resource description
A–D use these non-overlapping classes: 0 to less than 10%; 10 to less than 20%; 20 to less than 30%; 30 to less than 40%. A has 1,000 households and D has 100 households.
1 mark1. Which class contains district C?
- 10 to less than 20%
- 20 to less than 30%
- 30 to less than 40%
1 mark2. How many households in A reported damage?
1 mark3. Does the darkest district necessarily have the most affected households?
- Yes; darkest always means the highest count.
- No; the household denominators differ.
Supplementary geographical skill: Climate graphs
Use the accompanying exact monthly values for calculations. Both axes begin at zero.
Scroll the diagram sideways to see the full resource.
| Month | Rainfall (mm) | Temperature (°C) |
|---|---|---|
| Jan | 79 | 7 |
| Feb | 41 | 8 |
| Mar | 120 | 11 |
| Apr | 92 | 14 |
| May | 96 | 18 |
| Jun | 68 | 21 |
| Jul | 127 | 23 |
| Aug | 106 | 22 |
| Sep | 45 | 19 |
| Oct | 90 | 15 |
| Nov | 85 | 11 |
| Dec | 115 | 8 |
Resource description
Jan: 79 mm, 7°C; Feb: 41 mm, 8°C; Mar: 120 mm, 11°C; Apr: 92 mm, 14°C; May: 96 mm, 18°C; Jun: 68 mm, 21°C; Jul: 127 mm, 23°C; Aug: 106 mm, 22°C; Sep: 45 mm, 19°C; Oct: 90 mm, 15°C; Nov: 85 mm, 11°C; Dec: 115 mm, 8°C
1 mark1. What is the total annual rainfall in mm?
1 mark2. What is the annual temperature range in °C?
1 mark3. In which month is the highest mean temperature?
- Jan
- Apr
- Jul
- Oct
Supplementary geographical skill: Mean, median and range
Each observation uses the same area. One count is much higher than the others; keep it in the calculations.
| Site | Litter items in a 10 m² quadrat |
|---|---|
| Site 1 | 22 |
| Site 2 | 42 |
| Site 3 | 19 |
| Site 4 | 19 |
| Site 5 | 20 |
Resource description
Fictional field observations
1 mark1. What is the mean count?
1 mark2. What is the median count?
1 mark3. What is the range?
1 mark4. Which summary is less influenced by the extreme count?
- Mean
- Median
Supplementary geographical skill: Climate graphs
Use the accompanying exact monthly values for calculations. Both axes begin at zero.
Scroll the diagram sideways to see the full resource.
| Month | Rainfall (mm) | Temperature (°C) |
|---|---|---|
| Jan | 35 | 5 |
| Feb | 30 | 6 |
| Mar | 40 | 9 |
| Apr | 29 | 12 |
| May | 76 | 16 |
| Jun | 89 | 19 |
| Jul | 82 | 21 |
| Aug | 112 | 20 |
| Sep | 77 | 17 |
| Oct | 19 | 13 |
| Nov | 19 | 9 |
| Dec | 30 | 6 |
Resource description
Jan: 35 mm, 5°C; Feb: 30 mm, 6°C; Mar: 40 mm, 9°C; Apr: 29 mm, 12°C; May: 76 mm, 16°C; Jun: 89 mm, 19°C; Jul: 82 mm, 21°C; Aug: 112 mm, 20°C; Sep: 77 mm, 17°C; Oct: 19 mm, 13°C; Nov: 19 mm, 9°C; Dec: 30 mm, 6°C
1 mark1. What is the total annual rainfall in mm?
1 mark2. What is the annual temperature range in °C?
1 mark3. In which month is the highest mean temperature?
- Jan
- Apr
- Jul
- Oct
Supplementary geographical skill: River discharge
Use the explicitly rectangular cross section. The supplied mean velocity represents the whole cross section; it is not an uncorrected surface-float velocity.
| Measurement | Value |
|---|---|
| Width (m) | 3 |
| Uniform depth (m) | 0.7 |
| Mean cross-sectional velocity (m/s) | 0.6 |
Resource description
Idealised fictional rectangular channel
1 mark1. What is the cross-sectional area in m²?
1 mark2. What is discharge in m³/s?
Supplementary geographical skill: River discharge
Use the explicitly rectangular cross section. The supplied mean velocity represents the whole cross section; it is not an uncorrected surface-float velocity.
| Measurement | Value |
|---|---|
| Width (m) | 8 |
| Uniform depth (m) | 0.8 |
| Mean cross-sectional velocity (m/s) | 1.2 |
Resource description
Idealised fictional rectangular channel
1 mark1. What is the cross-sectional area in m²?
1 mark2. What is discharge in m³/s?
Supplementary geographical skill: River discharge
Use the explicitly rectangular cross section. The supplied mean velocity represents the whole cross section; it is not an uncorrected surface-float velocity.
| Measurement | Value |
|---|---|
| Width (m) | 7 |
| Uniform depth (m) | 0.3 |
| Mean cross-sectional velocity (m/s) | 0.2 |
Resource description
Idealised fictional rectangular channel
1 mark1. What is the cross-sectional area in m²?
1 mark2. What is discharge in m³/s?
Supplementary geographical skill: Review a questionnaire sample
Fictional training exercise. A survey about a proposed town-centre cycle lane collects responses at a cycle shop.
| Response | Number |
|---|---|
| Support | 42 |
| Oppose | 8 |
1 mark1. What percentage of this sample supports the lane?
1 mark2. Which claim does the sample support?
- 84% of all town residents support it
- 84% of the 50 respondents support it
- Everyone who cycles supports it
2 marks3. How could the team improve representation while protecting respondents?
Original fictional model and resources: GeographyHelp. · Written practice context: https://www.aqa.org.uk/files/2vT3LmcUzNO62qpl9IGZTD/c0b2adecbe1ddb3d7be035ff60b948743c186a82.pdf
Mark guidance
This original review does not award levels, SPaG or precise marks. Evaluation needs a judgement linked to the particular question.
Original application practice, not a complete examination paper. No assessed investigation, assignment, folio or restricted resource is reproduced.
The linked template fixes its coherent core resources. Resource type and skill selections control the explicitly labelled supplementary geographical skills.
A storm, its hydrograph and flood management
1. What is peak discharge in m³/s? (1 mark)
29
Read the maximum on the discharge line and its left axis.
2. What is the peak lag time in hours? (1 mark)
5
Maximum rainfall is at hour 2; maximum discharge is at hour 7. Subtract 2.
3. What can this record establish? (1 mark)
The discharge peak follows the rainfall peak in this storm.
Travel time and storage can delay discharge, but one record does not identify a unique mechanism or prove a universal lag.
4. Calculate homes in the mapped extent at the town reach. (1 mark)
950
1900 × 50/100.
5. Explain one way impermeable surfaces may affect the storm response, and one reason this record cannot isolate their effect. (4 marks)
Impermeable surfaces can reduce infiltration and increase rapid runoff. Rainfall pattern, antecedent moisture, basin shape and drainage also affect discharge; one storm is not a controlled comparison.
6. Recommend an option for a storm, its hydrograph and flood management. Use at least two resources, compare an alternative and address an uncertainty or stakeholder concern. (9 marks)
Different options are defensible. State your priority, use accurate evidence from the flood model, explain the geographical relationships and compare benefits and limitations. Rainfall is transformed through drainage-basin stores and flows, while exposure shapes the effects. No option is universally best.
Supplementary geographical skill: Choropleth maps
1. Which class contains district C? (1 mark)
20 to less than 30%
21 is at least 20 and below 30. For this 1-mark task, credit the keyed option.
2. How many households in A reported damage? (1 mark)
20
2% of 1,000 = 20. For this 1-mark task, credit the accepted numerical answer in the requested units.
3. Does the darkest district necessarily have the most affected households? (1 mark)
No; the household denominators differ.
A high rate in a small population can represent fewer households than a lower rate in a large population. For this 1-mark task, credit the keyed option.
Supplementary geographical skill: Climate graphs
1. What is the total annual rainfall in mm? (1 mark)
1064
Add the rainfall for all twelve months. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is the annual temperature range in °C? (1 mark)
16
Subtract the lowest monthly temperature from the highest. For this 1-mark task, credit the accepted numerical answer in the requested units.
3. In which month is the highest mean temperature? (1 mark)
Jul
Identify the highest point on the temperature line. For this 1-mark task, credit the keyed option.
Supplementary geographical skill: Mean, median and range
1. What is the mean count? (1 mark)
24.4
Add the 5 values and divide by 5. Mean = 24.4. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is the median count? (1 mark)
20
Sort the values. Use the middle value. For this 1-mark task, credit the accepted numerical answer in the requested units.
3. What is the range? (1 mark)
23
Subtract the smallest count from the largest. For this 1-mark task, credit the accepted numerical answer in the requested units.
4. Which summary is less influenced by the extreme count? (1 mark)
Median
The median depends on the middle positions rather than the magnitude of the extreme count. For this 1-mark task, credit the keyed option.
Supplementary geographical skill: Climate graphs
1. What is the total annual rainfall in mm? (1 mark)
638
Add the rainfall for all twelve months. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is the annual temperature range in °C? (1 mark)
16
Subtract the lowest monthly temperature from the highest. For this 1-mark task, credit the accepted numerical answer in the requested units.
3. In which month is the highest mean temperature? (1 mark)
Jul
Identify the highest point on the temperature line. For this 1-mark task, credit the keyed option.
Supplementary geographical skill: River discharge
1. What is the cross-sectional area in m²? (1 mark)
2.1
Width × depth. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is discharge in m³/s? (1 mark)
1.26
Cross-sectional area × mean cross-sectional velocity. For this 1-mark task, credit the accepted numerical answer in the requested units.
Supplementary geographical skill: River discharge
1. What is the cross-sectional area in m²? (1 mark)
6.4
Width × depth. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is discharge in m³/s? (1 mark)
7.68
Cross-sectional area × mean cross-sectional velocity. For this 1-mark task, credit the accepted numerical answer in the requested units.
Supplementary geographical skill: River discharge
1. What is the cross-sectional area in m²? (1 mark)
2.1
Width × depth. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. What is discharge in m³/s? (1 mark)
0.42
Cross-sectional area × mean cross-sectional velocity. For this 1-mark task, credit the accepted numerical answer in the requested units.
Supplementary geographical skill: Review a questionnaire sample
1. What percentage of this sample supports the lane? (1 mark)
84
42 ÷ 50 × 100 = 84%. For this 1-mark task, credit the accepted numerical answer in the requested units.
2. Which claim does the sample support? (1 mark)
84% of the 50 respondents support it
The sample was taken at one location and may overrepresent cycling interests. For this 1-mark task, credit the keyed option.
3. How could the team improve representation while protecting respondents? (2 marks)
Use several locations and time periods with a consistent selection rule; explain voluntary participation and avoid collecting names or unnecessary identifying details. Sampling changes reduce bias but do not guarantee a representative result.
Use several locations and time periods with a consistent selection rule; explain voluntary participation and avoid collecting names or unnecessary identifying details. Sampling changes reduce bias but do not guarantee a representative result. Original credit guidance: credit relevant explained reasoning; accept accurate alternatives.