1.3 River Landscapes

Question 1

Define Ribbon Lake

Answer 1

Large, narrow lake, occupying a v-shaped valley

Question 2

Define V-Shaped Valley

Answer 2

A valley formed where a glacier used to be

Question 3

Define Meltwater

Answer 3

River which form when glaciers melt

Question 4

Define Moraine

Answer 4

A mass of rocks/ sediment carried and deposited by a glacier

Question 5

Define Hydraulic Action

Answer 5

Water is forced into cracks in the rock and air is forced out explosively, breaking off pieces of the banks

Question 6

Define Abrasion

Answer 6

This is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.

Question 7

Define Attrition

Answer 7

This is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.

Question 8

Define Corrosion

Answer 8

When acid rain causes chemical weathering

Question 9

Define Chemical Weathering

Answer 9

Acids in seawater slowly dissolve rocks

Question 10

Define Biological Weathering

Answer 10

Roots of growing plants and burrowing animals or nesting birds can cause rocks to weather

Question 11

Define Mechanical Weathering

Answer 11

Caused by repeated freezing and thawing of water in a crack or hole in the rock.

Question 12

What is deposition?

Answer 12

When sediment, usually carried by waves is laid down or deposited

Question 13

When does deposition occur?

Answer 13

When their is not enough energy to carry sediment any further

Question 14

Define Source

Answer 14

The beginning of the river

Question 15

Define Confluence

Answer 15

Where 2 rivers meet

Question 16

Define Watershed

Answer 16

An area of highland between two drainage basins

Question 17

Define Mouth

Answer 17

Where a river flows into a lake or the sea

Question 18

Define Tributary

Answer 18

A small river/ stream that flows into a larger river

Question 19

Drainage Basin

Answer 19

The area drained by a river and its tributaries

Question 20

How does the channels shape change through the course of a river?

Answer 20

The channel becomes larger the further down the river it is.

Question 21

How does the gradient change through a river course?

Answer 21

Decreases. The gradient starts very steep but the steepness evens out as it reaches the lower course.

Question 22

How does the discharge change through a river course?

Answer 22

It increases as it goes down the river.

Question 23

How does the velocity change through a river course?

Answer 23

It increases due to less friction.

Question 24

How does the sediment size change through a river course?

Answer 24

The sediments erode one another getting smaller through the river course.

Question 25

Describe how a plunge-pool forms

Answer 25

When hard rockets on top of soft rock, the waves erode at the soft rock creating an undercut. Hydraulic action and abrasion then deepen this into a plunge-pool.

Question 26

What is likely to occur if you have an overhang?

Answer 26

The overhang is likely to collapse

Question 27

On which side of a bend does water travel faster?

Answer 27

Outside

Question 28

What forms on the outside bends of rivers?

Answer 28

River Cliffs

Question 29

What forms on the inside bends of rivers?

Answer 29

``` Point Bar (Slip-off Slope) ```

Question 30

Describe levees

Answer 30

A natural (or artificial) wall that increases the height of a river bank to prevent flooding.

Question 31

Describe Channelisation

Answer 31

Widening or deepening the river to increase the discharge

Question 32

Describe Flood Relief Channels

Answer 32

Channels made to relieve a river from high discharge

Question 33

Describe Dams and Reservoirs

Answer 33

Large (usually artificial) lakes used to collect water and store it.

Question 34

Describe Washlands

Answer 34

Areas of land near a river allowed to flood to take stress of off other areas

Question 35

Describe River Restoration

Answer 35

The process of restoring a river to improve natural process

Question 36

Describe Floodplain Zoning

Answer 36

This involves placing restrictions on land usage in the areas surrounding a river.

Question 37

Describe Vertical Erosion

Answer 37

Erosion of the bed

Question 38

Describe Lateral Erosion

Answer 38

Erosion of the sides

Question 39

Describe the formation of Oxbow Lakes

Answer 39

As a Meander becomes deeper and deeper, the river may meet itself and then find another path, this leaves an oxbow lake

Question 40

Describe Meanders

Answer 40

As river rushes around bends, the outside is eroded more than the inside, this causes bends called meander

Question 41

What is the Tees-Exe line?

Answer 41

A line which separates highland and lowland Britain

Question 42

Describe a River Profile

Answer 42

Altitude decreases as the river gets further from the source

Question 43

How does depth change down the river?

Answer 43

Gets deeper down the river

Question 44

How does valley profile change down a river?

Answer 44

In the upper course it is narrow and steep, it gets wider and the banks slope more further down the river

Question 45

What is the shape and size of sediment in the upper course?

Answer 45

Angular Boulders

Question 46

What is the shape and size of sediment in the middle course?

Answer 46

Rounded Rocks

Question 47

What is the shape and size of sediment in the lower course?

Answer 47

Smooth, Round Pebbles

Question 48

What are the three sections a river can be broken down into?

Answer 48

Upper Course Middle Course Lower Course

Question 49

What features are present in the upper course?

Answer 49

Waterfalls Gorges Interlocking Spurs V-shaped valley

Question 50

What features are present in the middle course?

Answer 50

Meanders Floodplain Gentle Slopes

Question 51

What features are present in the lower course?

Answer 51

``` Meanders Floodplain Estuary Levees Ox-bow Lake ```

Question 52

What features are present in the mouth of a river?

Answer 52

Deltas

Question 53

What model shows us how features of a river change across the profile?

Answer 53

Bradshaw Model

Question 54

Define Irrigation

Answer 54

A method in which a controlled amount of water is supplied to plants at regular intervals for agriculture

Question 55

Define Saturated

Answer 55

Holding as much water or moisture as can be absorbed

Question 56

What are 6 physical causes of flooding in the UK?

Answer 56

``` Impermeable Rock Steep Valley Sides Hot, Dry Weather Ploughing Slopes Deforestation Dams Burst ```

Question 57

How do impermeable rocks contribute to flooding?

Answer 57

Water does not soak into the ground, causing more surface run-off

Question 58

How do steep valley sides contribute to flooding?

Answer 58

More water runs down to the river, increasing discharge so that less is needed to cause the flood

Question 59

How does hot, dry weather contribute to flooding?

Answer 59

Means that the soil becomes hard and water cannot soak in

Question 60

How do dam bursts contribute to flooding?

Answer 60

Greatly increases discharge and water in the area

Question 61

How does deforestation contribute to flooding?

Answer 61

Water is not soaked up by roots and therefore the soil is more quickly saturated, once soil is saturated, there is greater surface run-off

Question 62

How does ploughing contribute to flooding?

Answer 62

Soil can hold less water

Question 63

What do hydrographs show?

Answer 63

How a river responds to a storm event | They show the relationship between rainfall and river discharge

Question 64

Define the rising limb on a hydrograph

Answer 64

Line representing the rapid rise in water after a period of intense rainfall

Question 65

Define the falling limb on a hydrograph

Answer 65

Represents the reduction in the amount of rainfall reaching the river channel

Question 66

What is lag time? (Hydrographs)

Answer 66

The difference between the heaviest rainfall and the point at which the river contains the largest amount of water

Question 67

What factors influence lag time?

Answer 67

Size of a drainage basin Vegetation Velley side steepness Soil Type