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Flashcards in urban climate Deck (62):
1

what is the urban heat island effect?
e.g: Melbourne's heat island is...

- urban areas are warmer than surrounding rural areas
- Melbourne's heat island - 1.13 degrees

2

what is the urban heat island effect?
e.g: Melbourne's heat island is...

- urban areas are warmer than surrounding rural areas
- Melbourne's heat island - 1.13 degrees

3

venturi effect

- when the airflow of wind is squeezed, high velocities are produced
- this effect increases as buildings tend to get taller towards city centre

4

albedo?
examples?

the amount of heat reflected off certain surfaces
- grass albedo is 16-26%
- concrete albedo is 10-35%

5

sky view factor

the amount of sky we can see without our view being impacted by tall buildings

6

wider impact of urban heat island..

- UHI increases convection leading to showers and more chance of storms by up to 25%
- low pressure draws moist air in which increases cloud coverage
- urban areas receive up to 10% more coverage

7

downdraught effect

- air is being deflected (either up or down) when it hits the building
- predominantly on windward side of the building

8

speed effect

- air moves at a faster rate when there's a higher altitude
- friction near the ground causes a slower rate at a lower altitude

9

down wind eddy / counter current effect

- wind blows over building
- low pressure area on leeward side of building
- air sinks down to fill the area of low pressure
- forms a cycle of air movement currents

10

where does air pollution mainly come from?

- vehicle / transport emissions
- industry

11

particulate pollution

the release of particles and noxious gases into the atmosphere

12

photochemical pollution

creates smogs consisting of ozone and peroxyacetly nitrate (PAN)

13

Londons Pea Souper smog - 1953
- cause?
- why was it amplified?
- Deaths?

- cause: power stations and people heating homes with cheap coal
- amplified by: lack of wind
- 12,000 deaths

14

what did the London smog of 1953 lead to?

clean air act of 1956

15

why do HICs experience less pollution today?

- more money to invest in environment schemes
- more regulations in HICS
- HIC populations use cleaner energy sources
- LICs often based on manufacturing

16

long term impacts of air pollution

- shorter life expectancy
- increased health issues so people can't work so less income which slows economic growth
-loss of tourism

17

urban areas have ____% more precipitation than rural areas

5-15% more precipitation

18

why is there more urban precipitation?

- dust and pollution create more condensation nuclei

19

why is there a higher risk of flooding in urban areas?

- less vegetation so less evapotranspiration
- impermeable surfaces
- gutters and drains quickly carry water to rivers meaning lag time is shorter

20

ways of reducing air pollution

- urban green areas
- zoning of industry
- transport solutions
- clean air acts

21

how does urban greening help?

- vegetation absorbs CO2 and releases oxygen
- removes pollutants from air
- makes air cleaner/healthier

22

an example of urban greening

London
- mayor wants to increase amount of surface areas greened by 5% by 2030

23

how does zoning of industry help?

- placing industry on the outskirts of the city reduces the concentration of pollution
- less people driving into city to work in the factories
- air quality in city improves

24

examples of transport solutions

- congestion charges in the CBD
- public transport (eg: Curitiba bus system has taken 80% of population out of cars)
- carpool lane
- promoting greener transport such as bikes

25

clean air acts

- regulate industry and how much is being emitted
- regulates cars on how clean/efficient they are

26

what are SUDS?

- sustainable urban drainage systems
- water management strategies designed to drain surface water moire sustainably than traditional practices

27

types of SUDS

- swales
- wetland
- permeable pavements
- infiltration trenches
- green roofs

28

swales

- provide temporary storage for storm water to reduce peak flows
- encourage microbial decomposition

29

wetland

- increased biodiversity
- aesthetically pleasing

30

permeable pavemets

- reduces flooding
- pollutant removal takes place in sub-base material

31

infiltration trenches

- stone filled reservoirs which water gradually infiltrates
- pollutants removed by absorption and microbial decomposition

32

what three objectives are SUDS aimed towards?

- control quantity of run-off
- improve quality of run-off
- enhance nature conservation

33

venturi effect

- when the airflow of wind is squeezed, high velocities are produced
- this effect increases as buildings tend to get taller towards city centre

34

albedo?
examples?

the amount of heat reflected off certain surfaces
- grass albedo is 16-26%
- concrete albedo is 10-35%

35

sky view factor

the amount of sky we can see without our view being impacted by tall buildings

36

wider impact of urban heat island..

- UHI increases convection leading to showers and more chance of storms by up to 25%
- low pressure draws moist air in which increases cloud coverage
- urban areas receive up to 10% more coverage

37

downdraught effect

- air is being deflected (either up or down) when it hits the building
- predominantly on windward side of the building

38

speed effect

- air moves at a faster rate when there's a higher altitude
- friction near the ground causes a slower rate at a lower altitude

39

down wind eddy / counter current effect

- wind blows over building
- low pressure area on leeward side of building
- air sinks down to fill the area of low pressure
- forms a cycle of air movement currents

40

where does air pollution mainly come from?

- vehicle / transport emissions
- industry

41

particulate pollution

the release of particles and noxious gases into the atmosphere

42

photochemical pollution

creates smogs consisting of ozone and peroxyacetly nitrate (PAN)

43

Londons Pea Souper smog - 1953
- cause?
- why was it amplified?
- Deaths?

- cause: power stations and people heating homes with cheap coal
- amplified by: lack of wind
- 12,000 deaths

44

what did the London smog of 1953 lead to?

clean air act of 1956

45

why do HICs experience less pollution today?

- more money to invest in environment schemes
- more regulations in HICS
- HIC populations use cleaner energy sources
- LICs often based on manufacturing

46

long term impacts of air pollution

- shorter life expectancy
- increased health issues so people can't work so less income which slows economic growth
-loss of tourism

47

urban areas have ____% more precipitation than rural areas

5-15% more precipitation

48

why is there more urban precipitation?

- dust and pollution create more condensation nuclei

49

why is there a higher risk of flooding in urban areas?

- less vegetation so less evapotranspiration
- impermeable surfaces
- gutters and drains quickly carry water to rivers meaning lag time is shorter

50

ways of reducing air pollution

- urban green areas
- zoning of industry
- transport solutions
- clean air acts

51

how does urban greening help?

- vegetation absorbs CO2 and releases oxygen
- removes pollutants from air
- makes air cleaner/healthier

52

an example of urban greening

London
- mayor wants to increase amount of surface areas greened by 5% by 2030

53

how does zoning of industry help?

- placing industry on the outskirts of the city reduces the concentration of pollution
- less people driving into city to work in the factories
- air quality in city improves

54

examples of transport solutions

- congestion charges in the CBD
- public transport (eg: Curitiba bus system has taken 80% of population out of cars)
- carpool lane
- promoting greener transport such as bikes

55

clean air acts

- regulate industry and how much is being emitted
- regulates cars on how clean/efficient they are

56

what are SUDS?

- sustainable urban drainage systems
- water management strategies designed to drain surface water moire sustainably than traditional practices

57

types of SUDS

- swales
- wetland
- permeable pavements
- infiltration trenches
- green roofs

58

swales

- provide temporary storage for storm water to reduce peak flows
- encourage microbial decomposition

59

wetland

- increased biodiversity
- aesthetically pleasing

60

permeable pavemets

- reduces flooding
- pollutant removal takes place in sub-base material

61

infiltration trenches

- stone filled reservoirs which water gradually infiltrates
- pollutants removed by absorption and microbial decomposition

62

what three objectives are SUDS aimed towards?

- control quantity of run-off
- improve quality of run-off
- enhance nature conservation