Section C - River Landscapes In The UK

Question 1

what is the drainage basin

Answer 1

an area of land drained by a river and its tributaries

Question 2

what is the source

Answer 2

the start of a river

Question 3

what is the tributary

Answer 3

a small stream that joins a larger river

Question 4

what is the confluence

Answer 4

where a tributary joins a larger river

Question 5

what is the mouth

Answer 5

the end of a river, usually where a river joins the sea

Question 6

what is the watershed

Answer 6

the edge of a river basin

Question 7

how do the long profile of a river change from source to mouth?

Answer 7

> where the water is shallow and turbulent there is friction with the bed and banks, slowing the rate of flow
further downstream rhe river’s channel is much deeper. less water is in contact with the bed and banks and the velocity increases

Question 8

what does the long profile of a river show you

Answer 8

how the gradient changes over the different courses

Question 9

how does the cross profile of a river and its valley change downstream

Answer 9

> the river channel becomes wider and deeper with the river valley becoming wider and flatter. its sides are less steep
river management can alter the shape of a river channel and different ypes of rock or human activities
these changes downstream are due to the amout of water flowin in the river

Question 10

the changes to a valleys cross profile are mainly due to?

Answer 10

> channel erosion broadening

>flattening

Question 11

what does the cross profile show you

Answer 11

what a cross section of the river looke like

Question 12

River erosion : what is solution

Answer 12

the dissolving of soluble chemicals in water

Question 13

River erosion : what is hydraulic power

Answer 13

the power of the river water as they smash onto the river bed

Question 14

River erosion : what is abrasion

Answer 14

the effect of pebbles grinding against the river bed

Question 15

River erosion : what is attrition

Answer 15

pebbles carried by the river that knock against one another

Question 16

River transportation : what is traction

Answer 16

large pebbles rolled along the riverbed

Question 17

River transportation : what is suspension

Answer 17

particles carried within the water

Question 18

River transportation : what is solution

Answer 18

dissolved cgemicals often derived from pebbles

Question 19

River transportation : what is saltation

Answer 19

a bouncing motion of particles too heavy to be suspended

Question 20

What is river deposition and what is an example

Answer 20

when the water carrying sediment loses energy. this will happenin different places along the river. an example of this is a meander where the inside of the bend reduces rivere energy, resulting in deposition

Question 21

DEPOSITION : where are estuaries found

Answer 21

at the mouth of a river, where it meets the sea. the land is close to sea level and the river valley is at its widest

Question 22

EROSION : where are interlocking spurs found

Answer 22

found in a rivers upper course

Question 23

EROSION : how do interlocking spurs form

Answer 23

form because of vertical erosion wearing away the land to create a V shaped valley

Question 24

EROSION : how are waterfalls formed

Answer 24

formed when a river flows over a relatively resistant band or hard rock

Question 25

EROSION : what is a gorge

Answer 25

a narrow, steep sided valley that is usually found immediately downstream of a waterfall

Question 26

EROSION : how are gorges formed

Answer 26

formed by the gradual retreat by a waterfall

Question 27

DEPOSITION AND EROSION : what are meanders

Answer 27

wide bends of a river found mainly in lowland areas

Question 28

DEPOSITION : what are pools/riffles

Answer 28

meandering streams carrying coarse sediment

Question 29

DEPOSITION : where are pools found

Answer 29

pools are found on the outside bends of meanders where the faster flow erodes a deeper channel

Question 30

Deposition : how are riffles found

Answer 30

riffles are formed from the deposition of course sediment, also of high flow

Question 31

DEPOSITION AND EROSION : how is an ox bow lake formed

Answer 31

1) the neck of the meander is gradually eroded 2) water niw takes the shortest and steepest route 3) meander is cut off, forming an ox bow lake

Question 32

DEPOSITION : what is a floodpain

Answer 32

a floodplain is a wide, flat area of marshy lan on either side of a river, and found in the lower courses

Question 33

DEPOSITION : what is a levee

Answer 33

a raised river bed, found in its lower course. it is formed by flooding ober many years

Question 34

DEPOSITION : why is a ridge of sediment deposited

Answer 34

to build up the levee

Question 35

hard engineering - how do dams form a reservoir

Answer 35

the dam traps water, which builds up behind it, forming a reservoir

Question 36

what is an advantage of dams and reservoirs

Answer 36

can be used to produce electricity by passing the water through a turbine within the dam

Question 37

what is a disadvantage of dams and reservoirs

Answer 37

dams trap sediment which means the reservoir can hold less water

Question 38

what does hard engineering involve

Answer 38

involves building artificial structures which try to control rivers

Question 39

hard engineering - why straighten a river

Answer 39

so the water speeds up - therefore volumes of water can pass through an area quickly

Question 40

hard engineering - why dredge a river

Answer 40

so that it is deeper and can therefore hold more water

Question 41

what is an advantage of river straightening and dredging

Answer 41

more water can be held in the channel

Question 42

what is a disadvantage of river dredging

Answer 42

dredging needs to be done frequently

Question 43

hard engineering - what is embanking a river

Answer 43

raising the banks so it can hold more water

Question 44

what is an advantage of emankments

Answer 44

cheap with a one off cost

Question 45

what is a disadvantage of embankments

Answer 45

looks unnatural

Question 46

hard engineering - what happens with flood relief channels

Answer 46

the flood water flows into the relief channel and is taken either to an area where it can be absorbed, or re enters the river further down its course

Question 47

what is an advantage of flood relief channels

Answer 47

removes excess water from the river channel to reduce flooding

Question 48

wht is a disadvantage of flood relief channels

Answer 48

expensive to build

Question 49

soft engineering - what are some advantages of wetland and flood storage areas

Answer 49

>very efficient in storing water | >water can be stored to reduce the risk of flooding further downstream

Question 50

soft engineering - what is floodplain zoning

Answer 50

allowing only certain land uses on the floodplain to reduce the risk of flooding to houses and important buildings

Question 51

what is an advantage of floodplain zoning

Answer 51

more expensive buildings and land uses are further away from the river, so have reduced flood risk

Question 52

what is a disadvantage of floodplain zoning

Answer 52

not always possible to change existing land uses

Question 53

soft engineering - what does river restoration involve

Answer 53

using the natural processes and features of a river, such as meanders and wetlands, to slow river flow and reduce the likelihood of a major flood downstream

Question 54

what is an advante of flood warnings and preperations

Answer 54

people have time to protect their properties e.g. with sandbags

Question 55

what is a disadvantage of flood warnings and preperations

Answer 55

flash floods may happen too quicklyy for a warning to be effective

Question 56

when do river floods usually occur

Answer 56

after prolonged periods of rainfall, usually in winter

Question 57

when do sudden floods or flash floods usually occu

Answer 57

in summer

Question 58

PHYSICAL - how does geology increase flood risk

Answer 58

impermeable rocks do not allow water to pass through them and so it flows overland into river channels

Question 59

PHYSICAL - how does precipitaion increase flood risk

Answer 59

torrential rainstorms and/ or prolonged rainfall can lead to rapid flooding events

Question 60

PHYSICAL - how does relief increase flood risk

Answer 60

steep slopes means water flows much quicker into river channels over a short space of time

Question 61

HUMAN - how does agriculture increase flood risk

Answer 61

exposed soil can lead to increased runoff (especially if the field has been ploughed)

Question 62

HUMAN - how does urbanisation increase flood risk

Answer 62

impermeable surfaces like tarmac and concrete means water flows into drains too quickly

Question 63

HUMAN - how does deforestation increase flood risk

Answer 63

when the trees are removed, the water that would have been evaporated or stored flows into the river channel

Question 64

STORM HYDROGRAPH : what is the peak

Answer 64

the top/highest

Question 65

STORM HYDROGRAPH : what is the line

Answer 65

the discharge

Question 66

STORM HYDROGRAPH : what is the rainfall

Answer 66

the bars

Question 67

STORM HYDROGRAPH : what is the capacity

Answer 67

the rivers maximum amount of water it can hold

Question 68

STORM HYDROGRAPH : what is the rising limb

Answer 68

the faster it rises the greather the chance of floods

Question 69

how does the basin size influence hydrographs

Answer 69

the larger the basin, the longer the lag time and less chance of floods

Question 70

how does the relief influence hydrographs

Answer 70

the steeper the gradient, the quicker water enters the river - greater flood chance

Question 71

how does soil moisture influence hydrographs

Answer 71

saturated soil means increased surface run off, shorter lag time and increases flood chance

Question 72

how does land use influence hydrographs

Answer 72

tarmac and concrete is impermeable so it increases surface run off into drains. increased flood risk