Summary
The River Severn is the longest river in the UK, prone to flooding due to its large catchment area and flat floodplains. Flooding is caused by both natural factors like steep valleys and heavy rainfall, and human activities such as urban development and deforestation.
- Catchment Area — the area from which rainfall flows into a river. Example: The River Severn's catchment area is 11,420 km².
- Lag Time — the delay between peak rainfall and peak discharge in a river. Example: Urban areas reduce lag time due to impermeable surfaces.
- Floodplain — flat land near a river that naturally floods. Example: Tewkesbury is located on a floodplain.
- Hard Engineering — using structures to control water flow. Example: Flood walls in Shrewsbury.
- Soft Engineering — working with natural processes to manage floods. Example: Afforestation in the Pontbren Project.
Exam Tips
Key Definitions to Remember
- Discharge
- Hydrograph
- Interception
- Surface Runoff
- Hard Engineering
- Soft Engineering
Common Confusions
- Confusing hard and soft engineering
- Misunderstanding the role of impermeable surfaces in urban areas
Typical Exam Questions
- What are the physical causes of flooding on the River Severn? Steep valleys and heavy rainfall in the upper course.
- How does urban development affect flood risk? It increases surface runoff and reduces lag time.
- Describe a flood management strategy used on the River Severn. Flood walls in Shrewsbury protect against flooding.
What Examiners Usually Test
- Understanding of flood causes and impacts
- Ability to evaluate management strategies
- Use of specific case study details