River Landscapes

Question 1

What is the source of a River?

Answer 1

Where the river begins
Usually in Upland areas

Question 2

What is a watershed?

Answer 2

The edge of the drainage basin

Question 3

What is a tributary?

Answer 3

A small river that meets the main channel

Question 4

What is a river channel?

Answer 4

The name of the place where the water flows

Question 5

What is a confluence?

Answer 5

Where the tributary meets the main channel

Question 6

What is a river mouth?

Answer 6

Where the River meets the Sea

Question 7

What is a drainage basin?

Answer 7

The area that the river and its tributaries covers
Sometimes called the river catchment

Question 8

Why does the depth and width increase in a river?

Answer 8

More water is added from the tributaries at confluences

Hydraulic action and abrasion erode the channel vertically and laterally

Question 9

Why does the load/sediment size get smaller?

Answer 9

Attrition happens as the pebbles are carried downstream

Question 10

Why does the channel bed and banks get less rough/smoother

Answer 10

Abrasion, smooth, the banks

Question 11

Why does the velocity increase in a river?

Answer 11

In the upper course, it is slower because the channel is rough and stones are angular so there is lots of action

Question 12

Discharge measured in cubic metres per second/cumecs is calculated by
velocity X cross-section
why does discharge increase?

Answer 12

The bed and banks are smoother due to abrasion, so the water flows faster

The amount of water in the channel increases has tributaries Joiner, so there is more hydraulic action enlarging the channel

Question 13

Why does the gradient decrease in rivers?

Answer 13

In The upper course they’re mountain, so it’s deep, but it’s flat by the sea

More vertical erosion a planned as the water tries to get to sea level

Question 14

Why does the valley shape change from V shaped to widen flat?

Answer 14

In the other course, there is vertical erosion, but there is more lateral erosion near the mouth of the River

Question 15

Interlocking spurs
Where are they found?
What are they?

Answer 15

The upper course of a river

Water and material at Currys cut into the riverbed, creating a steep V shaped valley

River, not powerful enough to a road lottery through areas of hard rock, so wines and bends around the rocks

Question 16

Waterfalls and gorges
What are they?
Why do they exist?

Answer 16

The river flows down the cliff face
The softer rock is eroded easily by the hydraulic action and abrasion, enabling the river to cut down into the channel
Over lots of time, the river continues to erode the soft rock and a plunge pool develops
The overlaying hard rock is undercut and left unsupported until it collapses
The falling hard rocks cause further erosion and abrasion, and the waterfall begins to retreat upstream

Question 17

Slip off slope

Answer 17

Disposition takes place on the inside bend where the river flows slowly
Vishali channel, create greater friction, slows the river down
Sand and shingle are deposited on the inside bend, forming slip of slips

Question 18

Oxbow lakes
How do you they form?

Answer 18

Erosion on the outside, bend of a meander, causes the neck to become narrower
The neck of the meander continues to narrow until the river eventually breaks through to form a new river channel
The river flows along the shortest path bypassing the loop
Sediment is deposited on the river banks the meander becomes sealed off
An oxbow lake form

Question 19

Levees

Answer 19

When the river floods over its banks of the water spreads out and slows down
As it, does, it loses energy and deposits, the material it was carrying
Heavy material is deposited first close to the channel
Repeated flooding and deposition form, raise levees along the edges of the channel

Question 20

What is lag time?

Answer 20

The time between peak rainfall and peak discharge

Peak discharge is the amount of water in a river when it’s fullest may cause flood 

Question 21

Who is lag time longer, or shorter in urban over rural areas

Answer 21

Shorter
Concrete and drains
Lots of run-off
Short lag time

Question 22

Is the lag time shorter, or longer in a deep valley sided

Answer 22

Shorter
Water runs over surface rapidly
No time to infiltrate

Question 23

Is the lag time shorter or longer in areas of forest rather than open land

Answer 23

Both are long
Forest longer
Trees intercept the rain and store it

Question 24

Causes of river, flooding

Answer 24

Climate change - more extreme events
Urbanisation - drains shorts, lag, time, -impermeable concrete, run-off
Deforestation - less trees to store water - high peak discharge, short lag time
Winter snow ice - frozen, ground, -impermeable - rapid run-off - -snowmelts - short lag time increase -run off

Question 25

Hard engineering, aims rivers

Answer 25

To stop the river flooding by building structures, using concrete and machinery

Question 26

Soft engineering aims rivers

Answer 26

Works with natural processes, allowing the flood to occur, but minimise damage to people and the environment

Question 27

Dam Hard engineering
Advantages and disadvantages

Answer 27

Minimise flood risk downstream
Long-lasting
Produce hydroelectric power
Provide a local water supply

Very expensive to build
Suffer from algae growth

Question 28

Reservoir
hard engineering
Advantages disadvantages

Answer 28

Watersports
Good for Local economy
Natural looking
Support, aquatic, biodiversity

Displacement of settlements and loss of farmland/habitats

Question 29

Channelisation, hard engineering
Advantages and disadvantages

Answer 29

Phone takes water away from places at risk quickly

Increase risk of flooding down stream
Unattractive
Litter/waste dropped in
Reduced biodiversity
No vegetation on banks

Question 30

Floodplain zoning soft engineering
Advantages and disadvantages

Answer 30

Don’t build homes in high flood risk zones
Area attractive
Natural looking
Encourages natural processes
Provides habitats

During times of flood public or farmers, cannot access these areas
People prefer using for building flat/houses

Question 31

Washland, soft engineering
Advantages and disadvantages

Answer 31

Natural place for floodwater
Add to the fertility and soil structure, on flood plane
Encourages biodiversity
Provides habitats

Farmers may not be able to use it for growing crops anymore

Question 32

Flood wall

Answer 32

Hiya banks, so the river can hold more water when flooding
Ugly

Question 33

River restoration

Answer 33

Recreate natural landscapes like me and as of water in concrete channels

Question 34

Alerts of flood

Answer 34

People can get to safety or put sand bags outside doors