Rivers

Question 0

What are the features of the upper course of a river?

Answer 0

V-shaped valleys, interlocking spurs, rapids, waterfalls, gorges

Question 1

What are the three stages of the river?

Answer 1

The upper course
The middle course
The lower course

Question 2

What are features of the middle course?

Answer 2

U-shaped valleys, meanders, oxbow lakes

Question 3

What are features of the lower course of a river

Answer 3

Floodplains, deltas

Question 4

How are V-shaped valleys formed?

Answer 4

1- Rocks & sediment flowing quickly in a river erode it vertically downwards

2- the banks of the steep river are weathered away by rain and wind to form a steep, v-shape

Question 5

How are interlocking spurs formed?

Answer 5

Meanders in V-shaped valleys cause the tops of the valleys -the ‘spurs’- to line up and interlock

Question 6

How are waterfalls formed?

Answer 6

Water passes of a cliff of hard rock on top of soft rock

The water erodes away the soft rock leaving a ledge of hard rock above and a worn away bottom called a plunge pool

Eventually the ledge of hard rock above becomes too heavy and collapses, forming a waterfall

This process repeats over and over

Question 7

How are gorges/canyons formed?

Answer 7

As a waterfall continuously erodes and moves backwards, it leaves a strip of a river where it once was- this is called a gorge/canyon

Question 8

How are U-shaped valleys formed?

Answer 8

• Starts off as a V-shaped valley
• lots of snow falls and compounds to form a glacier
• the ice erodes the steep valleys of a V-shaped valley through abrasion and a process called plucking (rocks in the valley getting stuck to the ice and literally pulled out of the ground)
• when this glacier melts, it leaves a much shallower valley: a U-shaped valley

Question 9

How are meanders formed?

Answer 9

• Rivers slow down as they enter the middle & lower course
• A slower river makes it easier for sediment to be deposited
• sediment is deposited on the inner edge of the river whilst the outer edge is eroded away, forming meanders

Question 10

How are rapids formed?

Answer 10

• Sections of soft and hard rock are next to each other at the bottom of a river
• when a river passes over, the soft rock is eroded and the hard rock isn’t leaving bumps in the river
• when the water goes over the bumps it bounces and splashes: this is a rapid

Question 11

How are oxbow lakes formed

Answer 11

• A meander becomes thinner and thinner over time
• At a time of flood the water overflows the meander and finds a shorter root, leaving the meander useless
• Over time sediment deposits at the entrance to the meander, completely separating it from the straight river
• this separated meander is called an oxbow lake

look at a picture and you’ll understand

Question 12

How is a delta formed?

Answer 12

• Rocks from the upper course are eroded away at high speeds and carried down stream
• these rocks are deposited at the bottom of the river as a sandy delta