Rivers

Question 1

Describe the upper course of a river

Answer 1

The river starts as many​ tributaries​, which are​narrow and V-shaped​.Each tributary doesn’t carry a lot of water, but combined the tributaries all fill up the river channel further down. The sides of the tributaries tend to be like a ​valley​,with a large gradient either side so water can run into the tributary.

Question 2

Describe the middle course of a river

Answer 2

The tributaries merge together to form a channel, which is rounder in shape and ​deeper. The area around the river channel is​flat and low-lying​,which is the ​floodplain​ if the river needs to flood

Question 3

Describe the lower course of the river

Answer 3

It carries the​largest volume of water in a very wide and very deep channel. There are ridges either side of the river banks called Levees. The size of the valley has increased, so it is even wider and flatter than the middle course

Question 4

What do storm hydrographs represent

Answer 4

Storm hydrographs represent the variation in the river’s​ discharge (the volume of water passing through the river channel at a specific point)within a short period.

Question 5

How does Topography increase the risk of river flooding

Answer 5

The​ shape of the land will determine how quickly rain water flows into the river.​Steep hills with​high gradients are more likely to have flash floods than gradual gradients.

Question 6

How does Geology increase the risk of river flooding

Answer 6

If the area has many​ impermeable rocks​,the rain water can’t run into the soil. Instead, the rain water runs straight into the river, increasing the risk of ​flash flooding

Question 7

How does rain increase the risk of river flooding

Answer 7

If there is a storm and a large amount of rain falls in a short amount of time, this can cause the river to flood

Question 8

What are the physical factors which increase the risk of river flooding

Answer 8

Rain
Geology
Topography

Question 9

How does Littering increase the risk of river flooding

Answer 9

If the river becomes filled with rubbish and debris, the channels size will decrease. This means the river can carry less water.

Question 10

How does Deforestation increase the risk of river flooding

Answer 10

Trees intercept rain and so it takes longer for the rain to travel through the leaves and into the river. Cutting trees shortens the time down

Question 11

How does urbanisation increase the risk of flooding in a river

Answer 11

Increases the amount of impermeable surfaces, which decreases the time taken for water to flow into the river

Question 12

What are the human factors which increase the risk of flooding

Answer 12

Urbanisation
Deforestation
Littering

Question 13

How are Mudflats and saltmarshes created

Answer 13

When both the tide from the estuary and the water flow from behind the river disrupt the rivers flow. There is a large amount of deposition. which creates mudflats and salt marshes

Question 14

What are river estuaries

Answer 14

Located at the mouth of the river, it is where the river meets the sea

Question 15

What is a leeve

Answer 15

They are river banks in the lower course of the river. they are higher than the river itself. They are a natural way of stopping river floodings

Question 16

How do meanders form

Answer 16

Water travels faster on the outside of the bend which causes lateral erosion

On the opposite side the water travels slowly and changes direction sharply until the water loses energy and deposit sediment

Question 17

What are Interlocking spurs

Answer 17

Interlocking spurs are found in the upper course of the river where the water doesn’t have a lot of energy so it isn’t very powerful

the low energy means the water isn’t strong enough to erode resistant rocks, instead the river rerouting curls around them

Question 18

What is Solution in rivers

Answer 18

Chemicals dissolved in the river water

Question 19

What is Suspension in rivers

Answer 19

Particles and small rocks are light enough to float within water

Question 20

What is Saltation in rivers

Answer 20

Pebbles and small rocks are to heavy to be suspended , bounce along the river channel

Question 21

What is Traction in rivers

Answer 21

Large rocks are rolled along the river bed

Question 22

What is deposition in rivers

Answer 22

Deposition is the dropping of the rivers load when the water in a river decreases in speed

If the River Travels slower, the water has less energy and can carry less material

Question 23

Which river land forms are found in the upper course of a river

Answer 23

-Waterfalls
-Interlocking spurs
-V shaped valley

Question 24

Which river land forms are found in the middle course of a river

Answer 24

-Gorges
-Meanders

Question 25

Which river land forms are found in the lower course of a river

Answer 25

-Flood plains
-Ox bow lake
-River estuary

Question 26

How do water falls form

Answer 26

In an area where a river flows
over an area of hard rock and
soft rock, the soft rock erodes
more quickly.

The soft rock erodes away from the hard rock over time creating a step

The soft rock continues to erode undercutting the hard rock The hard rock is left suspended in the air as an overhang

Due to the force of gravity the unsupported overhang collapses on the broken up rocks fall into the plunge pool which acts as tools for erosion and further deep into the plunge pool

Erosion continues to undercut underneath the hard rock creating overhang again further upstream

The continual process of the overhang collapsing causes the waterfall to retreat upstream

Question 27

What are gorges

Answer 27

Gorgeous form from water falls as the waterfall retreats upstream it leaves behind A steep valley carved into the rock with a river running along the base

Question 28

What are the two ways a storm hydrograph can be described as

Answer 28

flashy
subdued

Question 29

How can you tell with a storm hydrograph when there was a flash flooding

Answer 29

-Short lag time
-high maximum discharge

Question 30

How can you tell with a storm hydrograph when there was a subdued flooding

Answer 30

Longer lag time
Lower maximum discharge

Question 31

What are the soft engineering methods to reduce river flooding

Answer 31

River channel restoration
Wetlands

Question 32

What are the advantages and disadvantages of River channel resortation

Answer 32

+
Natural resources are used rather than heavily polluting ones
The natural environment benefits
~
Land will still flood, but often they are parks

Question 33

What are the advantages and disadvantages of Wetlands

Answer 33

+
Wet lands store river water and can flood when needed, with no damage to houses
~
takes a long time for wet land to grow

Question 34

What are the Hard engineering methods to reduce river flooding

Answer 34

Dams
Floodwalls

Question 35

What are the advantages and disadvantages of Dams

Answer 35

+
can control the amount of water which passes through
~
Very expensive

Question 36

What are the advantages and disadvantages of Flood walls

Answer 36

+
Protects valuable property on the river front.
~
Looks unnatural and destroys habitats along the bank

Question 37

What were the impacts of the Sheffield river flooding

Answer 37

-1,200 homes were flooded
-1,000 businesses were affected
​-13,000 people had no power​ for two days.