Pearson Edexcel GCSE Geography A (1GA0) · Spec 1.7, 1.8, 1.9 and 1.10
River landscapes and processes
Read the notes, then try the questions. Each one is marked the moment you press Check, and shows the right answer and why.
Key ideas
- A river's long profile is steep near the source and gentle near the mouth. Velocity and discharge normally increase downstream.
- Rivers erode by hydraulic action, abrasion, attrition and solution. Sediment becomes smaller and rounder downstream because of attrition and abrasion.
- In the upper course, erosion forms V-shaped valleys and waterfalls. A waterfall forms where hard rock lies over softer rock and the soft rock erodes faster. In the lower course, meanders, floodplains and ox-bow lakes form.
- A flood happens when a river's discharge is more than the channel can hold. Causes combine heavy rain, saturated or impermeable ground and steep slopes.
- Hard engineering includes dams, embankments and channel straightening. Soft engineering includes floodplain zoning, planting trees and flood warnings.
Key terms
- Discharge
- The volume of water passing a point in a river each second, measured in cubic metres per second (cumecs).
- Lag time
- The time between the peak of the rainfall and the peak discharge of the river.
- Suspension
- Fine material carried within the flowing water.
- Meander
- A bend in a river.
- Floodplain
- Flat land either side of a river that floods when the river overflows.
- Ox-bow lake
- A curved lake left when a meander is cut off from the river.
Common mistakes
- Saying rivers get wider because the water slows down. Velocity normally rises downstream. Rivers widen because of more lateral erosion and more water.
- Explaining a long lag time with 'it takes time for the rain to reach the river'. Give a reason such as infiltration, interception or throughflow.
- Blaming a flood on heavy rain only. Add the other causes, such as saturated ground, impermeable rock or steep slopes.
Exam tip
On the 8-marker for this option you are asked to Examine: say what each process does, how they link in order, and use evidence from both figures. Do not just describe the landform.
Free practice questions
6 questions, 9 marks. Answer, then press Check. The marking guide explains how the marks are worked out. Nothing is saved.
- Question 1 · Multiple choice[1 mark]
Which statement correctly defines suspension as a way a river transports sediment?
- Question 2 · True or false[1 mark]
Is this statement true or false?
- Question 3 · Multiple choice[1 mark]
Which statement best explains why a waterfall has formed at High Force on the River Tees?
- Question 4 · Multiple choice[1 mark]
A river has a very long lag time after heavy rain. Which statement best explains this?
- Question 5 · Fill the gaps[2 marks]
The long profile of a river is ___ near its source and ___ near its mouth.
Word bank: steep · wide · gentle
- Question 6 · Matching[3 marks]
Match each meander feature to where or how it forms.