OCR GCSE (9-1) Geography A: Geographical Themes (J383) · Spec 1.1.3 and 1.1.5
Rivers: processes and landforms
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
- In the upper course a river is steep and narrow. Erosion cuts downwards and makes a V-shaped valley. Lower down the valley is wide and flat and the river deposits more.
- A waterfall forms where hard rock lies over softer rock. The soft rock is eroded faster and a plunge pool forms. The overhang collapses and the waterfall retreats upstream, leaving a steep-sided gorge.
- On a meander the flow is fastest on the outside of the bend, so it erodes a river cliff. It is slowest on the inside, so it deposits a slip-off slope.
- An ox-bow lake forms when erosion narrows the neck of a meander. In a flood the river cuts through, and deposition seals off the old loop.
- When a river floods it loses energy and drops silt across the floodplain. The coarsest material drops first beside the channel and builds raised banks called levees.
- Your case study is one UK river basin. Name it, place its landforms, and explain them using its rock and climate. Show how people change it, for example with reservoirs or flood defences.
Key terms
- Long profile
- A side view of a river from its source to its mouth. It is steep near the source and gentle near the mouth.
- Plunge pool
- A deep pool at the foot of a waterfall, cut by falling water.
- Gorge
- A steep-sided valley left behind as a waterfall retreats upstream.
- Meander
- A bend in a river.
- River cliff
- A steep bank eroded on the outside of a meander.
- Slip-off slope
- A gentle bank of deposited material on the inside of a meander.
- Ox-bow lake
- A curved lake left when a meander loop is cut off from the river.
- Levee
- A raised bank beside a river, built from coarse material dropped in floods.
- Estuary
- The wide, tidal mouth of a river, where mudflats can form.
Common mistakes
- Putting erosion on the inside of a meander bend. Erosion is on the outside, where the flow is fastest. Deposition is on the inside.
- Naming a landform and stopping. A formation answer needs the whole sequence, with the process at each stage.
- Saying a levee is made by erosion. A levee is a landform of deposition.
Exam tip
A 4-mark 'explain' question on how a landform forms wants the sequence in order, with the process at each step. You may draw an annotated diagram. A waterfall is a good choice because every step uses a named process. On a case study question, accurate place detail raises your mark within a level, but it is the quality of your ideas that sets the level.
Free practice questions
7 questions, 12 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 describes the typical valley cross profile in the upper course of a river?
- Question 2 · Multiple choice[1 mark]
Which sequence forms an ox-bow lake?
- Question 3 · Put in order[1 mark]
Put the stages of waterfall and gorge formation in order.
Use the arrows to put these in the right order, first at the top.
- 1The soft rock is undercut and a plunge pool forms
- 2Hard rock lies over softer rock
- 3The overhanging hard rock collapses
- 4The waterfall retreats upstream, leaving a gorge
- Question 4 · Fill the gaps[2 marks]
On a meander the fastest flow causes ___ on the outside bend and slow flow causes ___ on the inside bend.
Word bank: erosion · deposition · attrition
- Question 5 · Matching[3 marks]
Match each meander feature to where or how it forms.
- Question 6 · True or false[3 marks]
Decide whether each statement about river processes is true or false.
1. Upper-course valleys are V-shaped.
2. Attrition is when stones knock together and become smaller and rounder.
3. Abrasion is when pebbles hit each other and become rounder.
- Question 7 · Multiple choice[1 mark]
How is a levée built?