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S5 Geography | River Landforms and Management Paper 1 (Foundation)
S5 Geography | River Landforms and Management Paper 1 (Foundation)
Paper 1 builds the basics: gradient and discharge calculations, suspended load, catchment runoff, sinuosity, incision rates, transport processes and the difference between upper and lower courses.
Separate cutting from filling Allow about twenty-five minutes; write the unit before substituting, and when marking decide whether the error was conversion, formula or concept.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 items |
| Suggested time | About 25 minutes |
| Difficulty mix | Foundation 4 · Intermediate 3 · Challenge 2 · Error redo 1 |
| Chapter | Chapter: S5 Geography | River Landforms and Management |
| Level | S5 (Secondary 5) Geography |
02 Questions (10 items)
- FoundationA river is 240 km long with a source 1,200 m above sea level. How much does it fall per kilometre, and what is that as a percentage?
- FoundationA channel has a cross-sectional area of 40 m² and a mean velocity of 1.5 m/s. What is the discharge?
- FoundationWith a suspended load of 0.8 kg/m³ and the same discharge, how much suspended sediment passes each second, and roughly how many tonnes per day?
- FoundationA 350 km² catchment receives 2,200 mm of rain a year with a runoff coefficient of 0.45. What is the annual runoff volume?
- IntermediateA meander is 4.5 km long while its two ends are 2.5 km apart. What is the sinuosity, and what does it tell you?
- IntermediateA valley is incising at an average of 0.5 mm per year. How deep is the incision after 10,000 years?
- IntermediateA river moves pebbles rolling along the bed, fine sand bouncing, and clay held in the water. Which transport process is each?
- ChallengeWhen flow suddenly slows, which settles first: coarse gravel or clay? Why?
- ChallengeA flood has a return period of 10 years. What is the annual probability, and the chance of at least one in the next 20 years?
- Error redoA common error is mixing up upper and lower courses. Which process dominates in each, and what landform results?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 5 m per km, that is 0.5% (1,200 / 240; 1,200 / 240,000). | Convert kilometres to metres first; a long profile is steep upstream and gentle downstream, so an average flattens the upper course. |
| 2 | 60 m³/s (40 × 1.5). | Discharge equals cross-sectional area times velocity, so a wider channel or faster flow both raise it. |
| 3 | 48 kg per second; about 4,147 tonnes per day (48 × 86,400 / 1,000). | Concentration times discharge gives mass per second; multiply by 86,400 seconds for a day, and divide by 1,000 for tonnes. |
| 4 | About 346,500,000 m³ (2.2 m × 350,000,000 m² × 0.45). | Convert rainfall to metres and area to square metres, then apply the runoff coefficient; omitting it overstates runoff badly. |
| 5 | 1.8 (4.5 / 2.5): the channel is 80% longer than the straight line, so flow is slower and deposition greater. | Sinuosity above about 1.5 means a highly meandering reach, with erosion on the outer bank and deposition on the inner bank. |
| 6 | 5 m (0.5 mm × 10,000 = 5,000 mm). | Convert millimetres to metres; a long-term average shows the trend, while individual flood events do most of the work. |
| 7 | Pebbles: traction; fine sand: saltation; clay: suspension. | Coarser material rolls or slides, finer material stays in suspension; dissolved load moves as solution. |
| 8 | Coarse gravel settles first because larger grains fall faster; clay stays in suspension longest. | Deposition is selective by grain size, which is why bed material becomes finer downstream. |
| 9 | 10% a year; about 87.8% over 20 years (1 – 0.9^20). | A return period is the reciprocal of the annual probability, not a fixed ten-year cycle. |
| 10 | Upper course: vertical incision, giving V-shaped valleys and waterfalls; lower course: lateral erosion and deposition, giving floodplains and deltas. | Remember “cut up, fill down”: narrow deep valleys upstream, wide shallow valleys downstream. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
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