River Environments 2

Question 1

the different forms of transport (4)

Answer 1

• traction: large boulders rolled on the bed
• saltation: small boulders bounced along the bed
• suspension: lighter material carried along by the river flow
• solution: material dissolved in the water

Question 2

transport

Answer 2

movement of load of river

Question 3

deposition (4)

Answer 3

• the laying down of materials transported by the river
• occurs when there is a decrease in energy, speed, discharge
• often when a river enters lake or sea
• or when there is a decrease in gradient of river chanel

Question 4

long profile

Answer 4

the section through a river or glacier course, from source to mouth

Question 5

interlocking spurs

Answer 5

a series of ridges projecting out on alternate sides of a valley and around which a river winds

Question 6

how do waterfalls form? (4)

Answer 6

• when a band of hard rock is more resistent to erosion than the softer rock beneath it
• the softer rock is eroded by the force of the water as it falls over the hard cap rock
• over time the waterfall creates a pool at the bottom of the falls
• slowly the hard rock is eroded away, so the waterfall retreats upstream

Question 7

meanders

Answer 7

winding curve in river’s course

Question 8

levees

Answer 8

raised bank of material deposited by a river during periods of flooding

Question 9

ox-bow lakes

Answer 9

a horse-shoe shaped lake once part of a meandering river, but now cut off from it

Question 10

water balance

Answer 10

comparing water demand and water supply

Question 11

why has the water demand risen? (4)

Answer 11

• population growth
• rising standard of living
• rise in agricultural productivity (irrigation)
• Industrialisation (factories)

Question 12

types of water supply (3)

Answer 12

• rivers and lakes
• reservoirs
• aquifers and wells

Question 13

agricultural water pollution (3)

Answer 13

• liquid from farm silage and slurry from farm animals that enters rivers
• fertilisers and pesticides that seep into groundwater
• deforestation, run off carries soils into rivers

Question 14

industrial water pollution (3)

Answer 14

• taking cooling water from river for an electric power station and returning it at a higher temp, this upsets river ecosystems
• spillages from industrial plants
• toxic substances find their way into rivers

Question 15

domestic water pollution (3)

Answer 15

• discharge of untreated sewage
• use of river for washing clothes and bathing
• emptying chlorinated swimming pools

Question 16

examples of water treatments (3)

Answer 16

• chlorination
• filtration
• disinfection

Question 17

examples of delivery of water (3)

Answer 17

• pipes (expensive and pipes can break)
• wells (takes a lot of time to collect from, contamination)
• plastic bottles (expensive)

Question 18

physical causes of flooding (6)

Answer 18

• weather
• rock
• soil
• relief
• drainage density
• vegetation

Question 19

human causes of flooding (4)

Answer 19

• deforestation
• urbanisation
• agriculture
• burning fossil fuels

Question 20

effects of flooding on environment (5)

Answer 20

• soil erosion
• loss of wildlife habitat
• landslides
• vegetation destroyed
• soil contamination by sewage

Question 21

effects of flooding on people (7)

Answer 21

• death and injury
• loss of belongings
• damage to property
• disruption to transport
• disease and stress
• crops and animals lost
• contamination of water supply

Question 22

Controlling Flooding (3)

Answer 22

• construction
• adjustment(mitigation)
• prediction

Question 23

explain filtration

Answer 23

to remove very fine sediments

Question 24

explain disinfection

Answer 24

to kill bacteria

Question 25

explain chlorination

Answer 25

to control any biological growth (algae)

Question 26

In what way can weather cause flooding? (3)

Answer 26

- run off is speeded up due to prolonged heavy rainfall - it exceeds the infiltration capacity and the ground becomes saturated - a sudden rise in temperature above freezing causes rapid snow melt

Question 27

In what way are rocks a factor that can cause flooding? (2)

Answer 27

- impermeable rocks limit percolation - and they encourage rapid surface run-off

Question 28

In what way is soil a factor that can cause flooding?

Answer 28

low infiltration capacity in some soils such as clay, speeds up run-off

Question 29

In what way can drainage density be a factor that can cause flooding?

Answer 29

high drainage density means that many tributary streams carry the rainwater quickly to the main river

Question 30

In what way can agriculture be a factor that can cause flooding? (3)

Answer 30

- soil left bare - overgrazing - monoculture

Question 31

In what way can urbanisation be a factor that can cause flooding?

Answer 31

concrete surfaces and drains mean quicker delivery of rainwater to the main river

Question 32

How can construction help control flooding? (2)

Answer 32

- by building hardengineering structures such as dams, artificial banks, sluice gates etc to hold back floodwater. - but these are very expensive to build

Question 33

how can adjustment/mitigation help to control flooding? (3)

Answer 33

- by trying to avoid or minimize potential flood damage. - it is called soft engineering, working with nature not against it. - for example= restoring a river to natural state or preserving marshes