Section C :rivers

Question 1

What is attrition?

Answer 1

Rocks knock against each other and become smaller and rounder

Question 2

What is solution?

Answer 2

The water dissolve certain types of rocks

Question 3

What is abrasion?

Answer 3

Pebbles grind along the river banks like sandpaper

Question 4

What is a Hydroalic action?

Answer 4

Water are smashing against riverbanks and cracks rocks

Question 5

What is traction?

Answer 5

Rocks are rolled along the river bed

Question 6

What is saltation?

Answer 6

Rocks are bounce along the riverbed

Question 7

What is suspension?

Answer 7

Lighter sediment is carried within the water

Question 8

What do you find in the upper course of a river?

Answer 8

V shaped valleys and interlocking spurs. These spurs are formed as a result of the river, trying to find the fastest way down towards the sea, the land then forms around the waterways, which is why there is spurs around the river. It erodes vertically.

Question 9

Explain the process involved in the formation of a landform

Answer 9

The resistant rock where the river flows over. Beneath the resistant rock that is softer less resistant rock. Through hydraulic action and abrasion, the softer rock erodes causing an undercut. The gravitational potential energy erodes the base of the waterfall to get a deep plunge pool. Eventually, the resistant rock will collapse, causing an over hang.

Question 10

Describe a flashy hydrograph

Answer 10

Has short leg time and high peak discharge

Steep slopes-water moves faster into the river from The Hills

High density-lots of streams will help rainfall get to the river more quickly

Urbanisation

Impermeable rock-encourage rapid overland flow

Very thin, soil

Thin Grassmoor land

Question 11

Describe other hydrographs

Answer 11

Long lag time and lower peak discharge

Gentle slopes-what are move slower into the river from The Hills

Low density-leads to slow transfer

Forest-trees will catch intercept water and use it for growth which reduces the amount of rain reaching the river

Permeable rock-slow transfer by ground water flow

Deep soil

Rural area

Question 12

Dams and reservoirs

Answer 12

How it works: during her reign for water can be stored, and then rainfall is low. It is released.

Pros: effective in regulating waterflow
Cons: cost huge amounts of money, floods, large areas of land, people have to be moved from houses.

Question 13

Channel straightening

Answer 13

How it works: cutting through meanders to create Straight channel

Pros: speeds up river flow, prevents banks from collapsing
Cons: flood risk upstream, unattractive an unnatural

Question 14

Embankments

Answer 14

How it works: a raised riverbank, which allows river channel to hold more water before flooding occurs. Includes concrete walls.

Pros: cheaper, most of stainable, looks more natural
Cons: nothing

Question 15

Flood relief channels

Answer 15

How it works: man-made river channel constructed to bypass urban areas.

Pros: reduces threat of flooding

Question 16

Describe the gradient of different parts of rivers

Answer 16

Lower-very gentle gradient
Middle-gentle
Upper-steep gradient

Question 17

Name, five ways of soft engineering for Rivers

Answer 17

Planting trees, wetlands+ Flood storage areas, floodplain, zoning, river, restoration, preparing for floods

Question 18

How do you Levees work?

Answer 18

Levees and naturally raised riverbanks, found on the side of a river channel that is prone to flooding. They formed after flood deposit sediment on the floodplain close to the river-is the water is spilling out across the land.Its velocity is reduced because of it fit friction which leads to deposition

Question 19

what does a long profile show

Answer 19

shows you a cross-section, taken sideways, of a river channel and/or valley at certain points in the rivers course

Question 20

Which stage of a river does lateral erosion take over from vertical erosion as the predominant type of erosion?

Answer 20

middle

Question 21

where does the majority of a rivers load come from?

Answer 21

The majority of a rivers load comes from Weatherred material that has ended the river Channel

Question 22

where is deposition most likely to occur

Answer 22

Shallow water due to energy levels being lower

Question 23

deposition occurs whenever a river loses energy and velocity falls. When will this not happen?

Answer 23

Deposition does not typically occur on the outside bend of meander because of velocity is high


Question 24

What can be formed when a meander bend is cut of

Answer 24

Oxbow Lake

Question 25

where can slip off slopes be found?

Answer 25

 inside bend of meander

Question 26

what is the name of the complex corkscrewlike motion of velocity within a river known as?

Answer 26

helicoidal flow

Question 27

 where are interlocking spores found along the course of a river?

Answer 27

upper 

Question 28

where is the velocity of a river greatest when it travels around meaner

Answer 28

Outside of the bend

Question 29

explain how an oxbow Lake Forms overtime

Answer 29

1 A meander neck is eroded over many years, until it becomes very narrow and then flood occurs

2 extra erosive power enables water from the main channel to break through the meander neck

3 flooding subsides , but most water in the river now follows the new shorter channel

4 deposition occurs at the side of the New channel, reducing flow around the old meander

5 overtime, further deposition cuts off the old meander completely ;create an oxbow lake 

Question 30

Give two advantages of hard engineering to manage the risk of river flooding

Answer 30

recreational or tourist value eg dams create reservoir

Protection of property creates economic savings

Question 31

Give two disadvantages of hard engineering to manage the risk of river flooding

Answer 31

expensive to install and maintain

Environmental damage; appearance may be unpopular; may create problems downstream

Question 32

“ the benefits of hard engineering strategies to minimise the risk of folding outweigh the cost”

Answer 32

Flood occurs every year across the UK, causing huge amounts of damage to property, making people temporarily homeless and closing businesses. Installing hard engineering methods such as flood in bank, the capacity of the river increases therefore flooding is less likely. People may argue that these are unattractive to look at, but they save millions of pounds in the repairs and insurance payouts, and also reduced the number of people who lose their homes.

Hard engineering is building dams, which control the flow of the water so less water reaches downstream, stopping flooding from a caring. However, land behind the dam is flooded creating as reservoir, meaning that some people could be displaced. Dams are incredibly expensive to construct but the reservoir created can provide a water supply to homes and businesses as well as creating a leisure amenity, which would provide jobs.

in conclusion I strongly agree that hard engineering is the best way to minimise the risk of flooding, and although there cost, these are outweigh by the social and economic benefits