Flood management and uncertainty
Guided practice
8035/3 geographical applications: issue-evaluation skills
Original practice assessment with editable questions and worked guidance.
A storm, its hydrograph and flood management
Use maps, data and stakeholder evidence to develop a geographical argument. The resources describe one fictional teaching scenario.
Options
Upstream storage and wetland restoration: £4.2 million
May reduce 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 reduce 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.
Scenario assumptions
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?
2 marks2. Calculate peak lag using the labelled hours of maximum rainfall and maximum discharge. Give your answer in hours.
1 mark3. Which explanation is consistent with, but not uniquely established by, this storm record?
- Peak discharge measures the total rain falling on the basin.
- Lag time measures the duration of flooding on the floodplain.
- The discharge peak identifies the basin’s infiltration capacity.
- Storage and travel time can delay the discharge response.
2 marks4. 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. Which option would best support reduced flood impacts across the catchment? Justify your choice using the supplied resources. State your priority, explain the geographical mechanism, compare alternatives and identify evidence that could change your judgement.
Supplementary geographical skill: Choropleth maps
The shading represents a percentage of households, not a total. Each class includes its lower boundary and excludes its upper boundary: a value of 20 belongs in 20–30, not 10–20.
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. What extra information is needed to compare affected-household counts?
- The household total for each district.
- The area of each district in square kilometres.
- The colour interval used in the legend.
- The number of districts in each colour class.
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?
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?
Original fictional model and resources: GeographyHelp. · Written practice context: https://filestore.aqa.org.uk/resources/geography/AQA-80353-SMS.PDF
Mark guidance
Compare the examples by their geographical reasoning, use of evidence and response to this question. Written guidance supports formative review; official levels and calibrated scores are not assigned.
Source mapping: flood issue evaluation.
Use your own taught place knowledge when the task or course requires it.
The linked template fixes its coherent core resources. Resource type and skill selections control the explicitly labelled supplementary geographical skills.
Assessment context: 8035/3 geographical applications: issue-evaluation skills. Use the resources and geographical understanding to build a reasoned answer. Source used to check the context · checked 2026-10-08
A storm, its hydrograph and flood management
1. What is peak discharge in m³/s? (1 mark)
Check the value, unit and method.
Credit criteria
- 1 mark: Correct value 29 m³/s.
Method: Read the maximum on the discharge line and its left axis.
Worked response
Read the discharge maximum on its labelled axis. Result: 29 m³/s.
Partial response and credit
A reading from the rainfall axis does not identify discharge. This one-mark read-off has no separate calculation-method credit.
Misinterpretation to check
Reads the rainfall peak in mm as discharge in m³/s.
Alternative reasoning
Accept 29 m³/s within the stated precision. Credit the correct reading; no method mark is available.
Credit the correct reading; no method mark is available.
2. Calculate peak lag using the labelled hours of maximum rainfall and maximum discharge. Give your answer in hours. (2 marks)
Check the value, unit and method.
Credit criteria
- 1 mark: Valid method: 7 − 2.
- 1 mark: Correct value 5 h.
Method: 7 − 2
Worked response
7 − 2. Result: 5 h.
Partial response and credit
A response showing 7 − 2 has a valid method even if its final arithmetic is incorrect. Retain method credit and check the final value separately.
Misinterpretation to check
Reports the hour of peak discharge rather than subtracting the hour of peak rainfall.
Alternative reasoning
Accept 5 h within the stated precision. A correct final calculation earns full credit without separate working; working can show a valid method when the final result is wrong.
3. Which explanation is consistent with, but not uniquely established by, this storm record? (1 mark)
Compare each option with the resource.
Credit criteria
- 1 mark: Select: Storage and travel time can delay the discharge response.
Worked response
Travel time and storage can delay discharge, but one record does not identify a unique mechanism or prove a universal lag.
Partial response and credit
This selected-response item has one keyed answer.
Misinterpretation to check
Check the unit, denominator and scope of each interpretation.
Alternative reasoning
Use the displayed resource to reject the other interpretations.
4. Calculate homes in the mapped extent at the town reach. (2 marks)
Check the value, unit and method.
Credit criteria
- 1 mark: Valid method: 1900 × 50/100.
- 1 mark: Correct value 950.
Method: 1900 × 50/100
Worked response
1900 × 50/100. Result: 950.
Partial response and credit
A response showing 1900 × 50/100 has a valid method even if its final arithmetic is incorrect. Retain method credit and check the final value separately.
Misinterpretation to check
Uses an incompatible denominator or mixes the units before calculating.
Alternative reasoning
Accept 950 within the stated precision. A correct final calculation earns full credit without separate working; working can show a valid method when the final result is wrong.
5. Explain one way impermeable surfaces may affect the storm response, and one reason this record cannot isolate their effect. (4 marks)
Use this guidance to compare the evidence and reasoning in your answer.
What a developed response includes
- Interpret the relevant pattern using precise resource evidence.
- Develop the geographical relationship asked for.
- Answer the question with a supported conclusion, addressing the evidence limits where relevant.
Worked response
Peak rainfall occurs at hour 2, while peak discharge occurs at hour 7; their difference is 5 hours. The storm reaches a peak discharge of 29 m³/s. The town reach has 65% impermeable cover compared with 20% upstream, and 950 town homes lie within the scenario extent. Impermeable cover can reduce infiltration and transfer rainfall to the channel more quickly. This may produce a faster response, but the record describes one storm; rainfall timing, how wet the ground was before the storm, drainage and basin form also affect discharge. The extent is a scenario footprint, not an annual probability.
Partial response and credit
Impermeable surfaces reduce infiltration and can increase rapid runoff.
Misinterpretation to check
The town surface-cover percentage establishes its annual flood probability.
Alternative reasoning
Ground that was already saturated could also produce rapid runoff, even where the surface is permeable. Repeated storms with rainfall and soil-moisture measurements would help distinguish these explanations.
Reviewing answer quality
Developing an answer: Identifies relevant details, but relationships or the answer to the exact question remain unclear.
Connected reasoning: Uses accurate evidence to explain geographical relationships and addresses the question.
Sustained reasoning: Selects and connects evidence, weighs a credible counterargument and reaches a supported judgement where the command requires it.
Teacher coverage notes
- Interpret the resource pattern or outcome — One storm and one footprint do not establish protection standards or performance under future rainfall. (One fictional storm record, Land cover and homes)
- Explain the relevant geographical relationship — One storm and one footprint do not establish protection standards or performance under future rainfall. (One fictional storm record, Land cover and homes)
- Assess what the evidence establishes — One storm and one footprint do not establish protection standards or performance under future rainfall. (One fictional storm record, Land cover and homes)
Judge the geographical argument against this question. The checklist and examples support formative review; they do not allocate official levels or calibrated written marks.
6. Which option would best support reduced flood impacts across the catchment? Justify your choice using the supplied resources. State your priority, explain the geographical mechanism, compare alternatives and identify evidence that could change your judgement. (9 marks)
Use this guidance to compare the evidence and reasoning in your answer.
What a developed response includes
- Select accurate resource evidence to support the stated priority.
- Explain how the intervention changes a geographical process or outcome.
- Develop a fair comparison and counterargument.
- Reach a judgement that respects funding, uncertainty and who benefits.
Partial response and credit
“I would choose the option called Upstream storage and wetland restoration because it could help.” This names an option. Add a cost, explain how it would help and compare it with an alternative.
Misinterpretation to check
The cheapest option must help every household equally. Capital cost alone does not establish effectiveness or the distribution of benefits.
Property adaptation and warnings
I would choose property adaptation and warnings to prioritise reducing damage and improving preparedness. Its £3.1 million capital cost fits the £8 million budget, leaving £4.9 million. Peak discharge is 29 m³/s; the town scenario includes 950 of its 1900 homes in the mapped extent. Adaptation can reduce damage when water enters buildings, while warnings can improve preparation and evacuation.
For £4.2 million, upstream storage and wetland restoration could hold back runoff before it reaches the town. For £7.5 million, the town flood wall could protect selected town assets below its design conditions. Floodwater and disruption to roads can remain; uptake, accessible warnings and household resources affect coverage. The downstream resident wants protection without extra risk being passed on. Any scheme needs a check on flows beyond the town.
I would reconsider if critical transport links need protection that household adaptation cannot provide.
Upstream storage and wetland restoration
I would choose upstream storage and wetland restoration to prioritise reducing the downstream flow peak. Its £4.2 million capital cost fits the £8 million budget, leaving £3.8 million. Peak discharge is 29 m³/s; the town scenario includes 950 of its 1900 homes in the mapped extent. Storage holds back some runoff and releases it later. Its position in the catchment links upstream land decisions to downstream exposure.
For £3.1 million, property adaptation and warnings could reduce damage and help households prepare. For £7.5 million, the town flood wall could protect selected town assets below its design conditions. Storage can fill before the flood peak arrives. How wet the ground was beforehand, land agreements and maintenance affect how much water it can hold back. The downstream resident wants protection without extra risk being passed on. Any scheme needs a check on flows beyond the town.
I would reconsider if storage capacity is insufficient for the relevant storms.
Town flood wall
I would choose the town flood wall to prioritise direct protection of selected town assets. Its £7.5 million capital cost fits the £8 million budget, leaving £0.5 million. Peak discharge is 29 m³/s; the town scenario includes 950 of its 1900 homes in the mapped extent. A wall can separate selected assets from water below its design conditions, targeting the exposed town reach.
For £3.1 million, property adaptation and warnings could reduce damage and help households prepare. For £4.2 million, upstream storage and wetland restoration could hold back runoff before it reaches the town. Overtopping, drainage behind the wall and displaced flows can leave residual risk in the town and downstream. The downstream resident wants protection without extra risk being passed on. Any scheme needs a check on flows beyond the town.
I would reconsider if protection transfers unacceptable risk or design conditions are exceeded.
Reviewing answer quality
Developing an answer: Identifies relevant details, but relationships or the answer to the exact question remain unclear.
Connected reasoning: Uses accurate evidence to explain geographical relationships and addresses the question.
Sustained reasoning: Selects and connects evidence, weighs a credible counterargument and reaches a supported judgement where the command requires it.
Teacher coverage notes
- Evaluate the stated priority or proposition — Several options can be defended against a stated priority and feasible funding. (One fictional storm record, Land cover and homes, Management alternatives)
- Explain the geographical mechanism — Several options can be defended against a stated priority and feasible funding. (One fictional storm record, Land cover and homes, Management alternatives)
- Compare the available alternatives — Several options can be defended against a stated priority and feasible funding. (One fictional storm record, Land cover and homes, Management alternatives)
- Reach a conditional judgement — Several options can be defended against a stated priority and feasible funding. (One fictional storm record, Land cover and homes, Management alternatives)
Judge the geographical argument against this question. The checklist and examples support formative review; they do not allocate official levels or calibrated written marks.
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. What extra information is needed to compare affected-household counts? (1 mark)
The household total for each district.
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.
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.