Rivers

Question 1

What features do you find in the upper course? (4)

Answer 1

Waterfalls, gorges, V-shaped valleys, interlocking spurs

Question 2

What features do you find in the middle course? (3)

Answer 2

meanders, floodplains, oxbow lakes

Question 3

What features do you find in the lower course? (4)

Answer 3

floodplains, mud flats, deltas, estuaries.

Question 4

Where do you find a waterfall?

Answer 4

upper course

Question 5

Where do you find interlocking spurs?

Answer 5

upper course

Question 6

Where do you find a gorge?

Answer 6

upper course

Question 7

Where do you find a v-shaped valley?

Answer 7

upper course

Question 8

Where do you find an oxbow lake?

Answer 8

middle course

Question 9

Where do you find a meander?

Answer 9

middle course

Question 10

Where do you find floodplains?

Answer 10

middle course or lower course

Question 11

Where do you find mud flats?

Answer 11

lower course

Question 12

Where do you find a delta?

Answer 12

In the lower course, where a river empties into another body of water

Question 13

Where do you find an estuary?

Answer 13

lower course

Question 14

How is a waterfall formed?

Answer 14

when a river starts flowing over harder rock. The water vertically erodes the softer rock, and eventually starts undercutting the hard rock. Over time, the overhang of harder will be less and less supported, and eventually fall into a plunge pool. It will eventually retreat up[ the river.

Question 15

What type of erosion happens when a waterfall retreating backwards?

Answer 15

Headward erosion

Question 16

What is headward erosion?

Answer 16

When a waterfall retreats backwards up a river

Question 17

What is a plunge pool?

Answer 17

The deep pool found at the bottom of a waterfall.

Question 18

What types of erosion create a plunge pool?

Answer 18

Hydraulic action and abrasion

Question 19

What is undercutting?

Answer 19

When the soft rock under the hard rock in a waterfall is eroded faster than the harder rock.

Question 20

When the hard rock falls into the river what is it called?

Answer 20

Load

Question 21

How is a gorge formed?

Answer 21

When a waterfall retreats backwards and leave a steep sided valley

Question 22

How are interlocking spurs formed?

Answer 22

Since a river is “Lazy”, it will take the shortest route- around the bases of hills. It will flow around them instead of “bothering” to cut a path through harder rock.

Question 23

How are v-shaped valleys formed?

Answer 23

V-shaped valleys are formed when a small stream naturally follows small depressions in the landscape, and over time weathering and gravity will wear away the steep valley sides. This forces material into the streams, which cuts the valley deeper. The bedload will helps the vertical erosion, making the sides steeper and more exposed.

Question 24

What is bedload?

Answer 24

What is carried along the floor of a river

Question 25

What is load?

Answer 25

Everything the river carries

Question 26

What is discharge?

Answer 26

the volume of water carried by a river

Question 27

What is braiding?

Answer 27

A network of rivers seperated by small often temporary islands.

Question 28

What are braid bars?

Answer 28

The small islands in a braided river

Question 29

What is abrasion?

Answer 29

When pebbles grind along the river bank and bed in a sand-papering effect.

Question 30

What is attrition?

Answer 30

When stones in the river knock against each other, gradually making them smaller and rounder

Question 31

What is hydraulic action?

Answer 31

This is the sheer power of the water as it smashes against the river banks. Air becomes trapped in the cracks of the river bank and bed, and causes the rock to break apart.

Question 32

What is solution? (erosion)

Answer 32

When water dissolves soluble materials from the bank or bed, which breaks them up.

Question 33

What is vertical erosion?

Answer 33

When gravity pulls the water down to erode the bed.

Question 34

What is lateral erosion?

Answer 34

Erosion of the banks, rather than the bed

Question 35

what is suspension? (load)

Answer 35

Fine, light materials carried by a river

Question 36

What is traction?

Answer 36

large boulders and rocks carried along the river bed

Question 37

What is solution (load)?

Answer 37

materials dissolved in the river

Question 38

what is a confluence?

Answer 38

When two rivers meet

Question 39

How is an oxbow lake formed?

Answer 39

when the neck of a meander gets thinner and thinner, and eventually forms two paths in the river that eventually meet up: one that goes round the original meander and one that goes the quicker, straighter route. The route to the original path eventually gets blocked off, and then the oxbow lake is left. It will eventually get filled in.

Question 40

What is the difference between a delta and an estuary?

Answer 40

an estuary is where freshwater meets saltwater, and it only happens in seas. A delta can happen in the lakes as well and it

Question 41

What is the key process in forming estuaries?

Answer 41

deposition

Question 42

What word can be used to describe a river at an estuary?

Answer 42

Tidal

Question 43

How does depostion occur in a delta?

Answer 43

When the river slows down, the load carried by the delta will be dropped off. Sometimes there is so much of it the river can't carry it away.

Question 44

What are the causes of flooding?

Answer 44

Built-up areas, deforestation, downhill slopes, lots of precipitation, snow melting, impermeable rock, settlements built on floodplains, already wet ground, dry ground.

Question 45

What does impermeable mean?

Answer 45

fluids can't pass through it

Question 46

What does saturated mean? (In terms of flooding)

Answer 46

When the ground holds too much water and can't take any more

Question 47

What is transportation?

Answer 47

When a river carries its load from one place to another

Question 48

What counts as load?

Answer 48

pebbles, sand,mud,rocks

Question 49

What is the difference between saltation and suspension and solution? (3 points)

Answer 49

Suspension is when load is dissolved (suspended) in the water , saltation is where pebbles are bounced along the riverbed , mostly near the source , solution is dissolved chemicals

Question 50

What is traction?

Answer 50

large heavy pebbles rolled along riverbed

Question 51

where is load largest?

Answer 51

near source

Question 52

What does watershed mean?

Answer 52

The circumference of the drainage basin; inside it any water will go into the river

Question 53

Why might a river deposit its load?

Answer 53

River slowing down, getting shallower, less volume