P1 - Unit 1C - River Landscapes In The UK

Question 1

What’s a cross profile of a river?

Answer 1

The side to side cross-section of a river channel and or valley

Question 2

What’s a long profile of a river?

Answer 2

The gradient of a river from its source to its mouth

-shows you how the gradient changes over the different courses

Question 3

What’s vertical and lateral erosion?

Answer 3

Vertical-downward

Lateral-sideways erosion

Question 4

What’s a river discharge?

Answer 4

The quantity of water that passes a certain point within a given period of time

Question 5

What’re the three sections of a river in its long profile?

Answer 5

Upper course, middle course, lower course

Question 6

What’s the Bradshaw model?

Answer 6

It’s a geographical model which describes how a river’s characteristics vary between the upper and lower course of a river.

Question 7

What’re the characteristics in the upper course of a river?

Answer 7

• steep gradient
• channel is shallow and narrow
• vertical erosion
• v-shaped valley, steep sides

Question 8

What’re the landforms found in the upper course of a river?

Answer 8

Interlocking spurs
Waterfalls
Gorges

Question 9

What’re the characteristics in the middle course of a river?

Answer 9

• medium gradient
• channel is deeper and wider
• more lateral and some vertical erosion
• gently sloping valley sides

Question 10

What’re the landforms found in the middle course of the river?

Answer 10

• meanders
• flood plains
• levées

Question 11

What’re the characteristics in the lower course of a river?

Answer 11

• gentle gradient
• channel is deepest and widest
• lateral erosion but loads of deposition
• very wide almost flat valley

Question 12

What’re the landforms in the lower course of a river?

Answer 12

• estuary
• meanders
• flood plain
• levées
• oxbow lakes

Question 13

What’re the four processes of erosion?

Answer 13

Abrasion, attrition, hydraulic action, solution

Question 14

Define abrasion/corrasion:

Answer 14

When smaller material, carried in suspension, rubs against the banks of the river(this cause a sand papering action)

Question 15

Define attrition:

Answer 15

When boulder or other material, which are being transported along the bed of the river, collide and break up into smaller pieces(this leads to rocks becoming more rounded)
-the further a material travels the more rounded and small it becomes

Question 16

Define hydraulic action:

Answer 16

When the sheer force of the river dislodges particles from the river bed and banks

Question 17

Define solution/corrosion:

Answer 17

When acids in the river dissolves rocks

e.g. chalk and limestone

Question 18

What’re the four types of transportation?

Answer 18

Traction
Saltation
Suspension
Solution

Question 19

Define traction:

Answer 19

Large boulders and rocks are rolled along the river bed by the force of the water

Question 20

Define saltation:

Answer 20

-small pebbles and stones are bounced along the river bed by the force of the water

Question 21

Define suspension:

Answer 21

Fine, light material is carried along by the river

Question 22

Define solution:

Answer 22

Minerals are dissolved in the water

-this is a chemical change

Question 23

Why does deposition take place?

Answer 23

Deposition occurs when the velocity of a river decreases, it no longer has enough energy to transport its sediment so it is deposited

Question 24

How is a waterfall formed?

Answer 24

• waterfalls are most commonly formed when a river flows over a resistant band of hard rock
• the less resistant rock beneath is eroded rapidly by hydraulic action and abrasion, undercutting the hard rock above
• When the river plunges over a waterfall it forms a deep plunge pool
• this creates a ledge of overhanging hard rock, eventually this rock collapses into the plunge pool
• the waterfall retreats upstream leaving a gorge behind

Question 25

What's a gorge?

Answer 25

A gorge is a narrow, steep-sided called, with bare, rocky walls. A gorge of recession is found immediately downstream of a waterfall.

Question 26

Describe a case study for a waterfall in the U.K:

Answer 26

High Force Waterfall, River Tees, Teesdale - has hard Whinsill cap rock, below this there's softer rock such as limestone, sandstone and shale - there's a 700m gorge - the waterfall is 21m high

Question 27

What features are there at a meander?

Answer 27

Inside of the bend- slip off slope, deposition | Outside of the bend-fastest flow(thelweg),river cliff, lateral erosion(hydraulic action, abrasion), deeper channel

Question 28

How do oxbow lakes form?

Answer 28

- due to erosion on the outside of the bend and deposition on the inside the shape of a meander will change over time - erosion narrows the neck of land between the meander - the neck is then eroded so that a new straighter channel is formed, the river will take this straighter route - deposition will eventually cut off the old meander to leave an oxbow lake

Question 29

What're levées?

Answer 29

Naturally raised river banks found on either or both sides of river which is prone to flooding

Question 30

How are levées formed?

Answer 30

- During a flood when a river bursts its banks it deposits sediment(heaviest load closest to the river deposited) - with every flood these banks of deposited sediment are built a little bit higher but also the river bed builds up bedload deposits over time so this increases the rivers probability of flooding

Question 31

How is a flood plain formed?

Answer 31

The width of a flood plain is due to meander migration where the outside bends erode laterally into the edges of the valley.

Question 32

Define flood plain:

Answer 32

A large area of land wither side of a river that is prone to flooding

Question 33

Define river estuary:

Answer 33

The tidal part of a river where the channel broadens out as it reaches the sea

Question 34

How's an estuary formed?

Answer 34

- a large river entered the sea at a narrow mouth before the last ice age - after the last ice age, the ice melted causing a rise in sea level, do either sides of the river became flooded, forming a estuary

Question 35

How are estuary mud flats formed?

Answer 35

Mudflats are formed in sheltered areas where tidal water flows slowly. As a river transports alluvium(mineral rich soil) to the sea, and incoming tide transports sand and marine silt up the estuary, where the waters meet velocity is reduced so deposition is increased

Question 36

Define drainage basin:

Answer 36

A river drainage basin(or catchment area) is an area of land drained by a river and its tributaries

Question 37

Define watershed:

Answer 37

The boundary between two drainage basins marked by a ridge of high land

Question 38

Define percolation:

Answer 38

Water seeping deeper below the surface into the rock

Question 39

Define transpiration:

Answer 39

Water lost through pores in vegetation

Question 40

Define interception:

Answer 40

Water being prevented from reaching the surface by trees and vegetation

Question 41

Define throughflow:

Answer 41

Water flowing through the soil layer parallel to the surface

Question 42

Define infiltration:

Answer 42

Water sinking into the soil from the ground surface

Question 43

Define groundwater flow:

Answer 43

Water flowing through the rock layer parallel tot the surface

Question 44

Define water table:

Answer 44

The upper level of saturated rock/soil where no more water can be absorbed

Question 45

What increases flood risk?

Answer 45

Bands of depression(rain) Sudden bursts of heavy rain(flash floods) Prolonged light rainfall Sudden snow melt

Question 46

What physical features can increase the risk of flooding?

Answer 46

Geology(type of rock), determines how long the rainfall takes to get to the river Relief(height and slop of the land), how much surface runoff there is depends on the rate by which water flows over the land

Question 47

What're human causes of flooding?

Answer 47

``` Urbanisation-infrastructure(more impermeable surfaces on the land), new houses(more houses built on greenfield sites), disappearing gardens(people will get rid of their garden to have a parking space which increase the amount of impermeable surfaces) Deforestation-reduces interception, roots no longer take water from the soil Agriculture-hedges have been ripped out, leaving soil bare in winter ```

Question 48

What's a hydrograph?

Answer 48

A hydrograph shows how a rivers discharge changes in response to a precipitation event.

Question 49

What are the two main ways to manage flooding?

Answer 49

Hard engineering-using man made structures to prevent or control natural processes from taking place Soft engineering-a strategy that involves adapting to a river and learning to live with it

Question 50

What're examples of hard engineering schemes to manage flooding?

Answer 50

- building dams and reservoirs - channel straightening - building embankments(artificially raised river bank) - making a flood relief channel

Question 51

What're examples of soft engineering schemes to manage flooding?

Answer 51

- flood plain zoning(where you plan out areas due to how high above the river they are) - flood warnings and preparation work - planting trees - river restoration

Question 52

What are the advantages and disadvantages of dams and reservoirs?

Answer 52

``` Advantages -boosts tourism -provides HEP Disadvantages -costs a lot to build -the reservoir can destroy areas of vegetation ```

Question 53

What're the advantages and disadvantages of channel straightening?

Answer 53

Advantages -water will flow through that area quicker because of less friction with banks -home owners gain confidence that they won't flood Disadvantages -expensive and dredging is also expensive -can endanger animals and destroy habitats

Question 54

What're the advantages and disadvantages of flood-relief channel?

Answer 54

Advantages -recreation can happen on the new channel(walking, canoeing) -the value of property in the area increases Disadvantages -expensive -habitats are disturbed int eh construction of the channel

Question 55

What're the advantages and disadvantages of river restoration?

Answer 55

``` Advantages -creates new wetland habitats and increases biodiversity -aesthetically pleasing Disadvantages -loss of agricultural land -can be expensive, initially ```

Question 56

What're the advantages and disadvantages of planting trees?

Answer 56

``` Advantages -reduces water flowing downstream as more water is used -encourages new habitats Disadvantages -loss of potential grazing land -costs to plant trees ```

Question 57

What're the advantages and disadvantages of flood plain zoning?

Answer 57

Advantages -low cost -by preserving the flood plain it provides more green space in towns Disadvantages -approach has limited impact -housing shortage in the U.K, restricting building makes the problem worse

Question 58

How is flooding managed in Cockermouth after the flooding at the confluence between the river Derwent and the river Cocker in November 2009?

Answer 58

- self raising barriers - flood warning services(81% of people signed up) - gravel removal from the river Derwent - embankments, walls and gates to lessen the risk

Question 59

When does the velocity of a river decrease?

Answer 59

- when the volume of water in the river falls - amount of eroded material being transported increases - water is shallower - river reaches its mouth