Year 7 Geography- Rivers (B and P groups)

Lesson 5 – Explain how a meander and an oxbow lake are formed

Success criteria: I can define meander and oxbow lake I can explain how a meander is formed I can explain how a meander becomes an oxbow lake I can draw and label a series of diagrams showing meander formation

Do now:

1. Rivers are used in agriculture for I…

2. When water is heated and rises into the air, it is called e…

3. Deposition (dropping material) happens when a river loses e…

4. What is formed when a waterfall retreats (moves backwards) upstream?

5. Name a job in the tertiary sector

6. Challenge: abrasion is when…

Meanders:

Start by watching this video: https://www.bbc.co.uk/bitesize/clips/zvm3cdm

A meander is a bend in a river

It starts with a slight bend. The The fast water erodes the Continued erosion and water moves faster on the outside of the bend. The deposition makes the bend outside of the bend and slower slower water deposits material bigger. on the inside of the bend. on the inside of the bend.

Complete the sentences below:

A meander is ______

A meander starts with a……………… The fast water…………….……………… Continued e…………………………….on …………………………………………………... Water moves the……………………………of the bend the……………………………of the bend and fastest…………………..………………………………………... d………………………………..on the

Water moves slowest……………………………………... The slow water…………….……………. material on …………………………………of the bend

the………………………….. of the bend makes………………………………………...

Challenge: suggest two types of erosion that occur on the outside of the bend

______Oxbow lakes:

Start by watching this video: https://www.bbc.co.uk/bitesize/clips/zrhc87h

An oxbow lake is a U shaped lake near a river

Over time, erosion makes the Eventually the neck of the As less water is flowing through meander bend larger and larger. meander breaks through and the the meander, the energy is The neck of the meander water takes the most direct reduced. Material is deposited, narrows. route, avoiding the meander. blocking off the meander and creating an oxbow lake.

Complete the sentence starters on the next page.

An oxbow lake is ______

Continued…………………………makes the Eventually the……………….…..of the meander As no water is flowing through the meander,

bend…………………………………….. As a result breaks through and the water takes the the energy…………….

the……………………of the meander most direct route avoiding …………………………………………………...

gets…………………………… the……………………………….. As a result material is………………….

………………………………………………….., blocking

off the………………………….. and creating

an…………………………..

…………………………………………………..

Exit ticket:

What is the name of the landform in the picture? ______

What is going to happen to that landform over time? ______

Does water flow fastest on the inside or the outside of the bend?

______

Where is material dropped (deposited), the inside or the outside of the bend?

______

Challenge: On paper, and without looking at your notes, draw and label the three stages of meander formation.