Lesson 17-The Urban Heat Island Effect

Question 1

Urban Heat Island effect

Answer 1

Urban and suburban areas that experience higher temps than the surrounding rural areas

Question 2

Notes of UHI

Answer 2

• Temp difference can be as much as 12 degrees celcius in cities
• Temps fluctuate in urban areas dependant on season, weather, sun intensity and ground cover
• Typically the largest in summer
• Effect tends to decrease as city size decreases

Question 3

Trends of the UHI effect

Answer 3

• Urban temps are highest in mid afternoon over the CBD
• Secondary peaks of high temps away from CBD appear over built up suburban areas, edge cities
• Temp range from rural fringe to city is the greatest at night due to high heat storage capacity of buildings compared to vegetation

Question 4

1) Causes of UHI effect
USA

Answer 4

• Urban areas are designed to dispose of surface water quickly-reduces evaporation
• Surfaces in the city tend to be much less reflective than those in rural areas as building materiels like concrete have much lower albedo and act like rock surfaces absorbing large quantities of heat during the day
• Air pollution from indutries and vehciles increases cloud cover and creates pollution dome

Question 5

2) Causes of UHI effect
HEA

Answer 5

• Heat comes from industries and vehicles, which both burn fuel (combustiuon process releases heat, warming the microclimate)
• Peoplle generate heat, dense populations warm the city
• Air conditioning contributes to the UHI as the units release hot air back into environment

Question 6

Social weaknesses of the UHI effect

Answer 6

• Extreme heat island effects increases the cases of heat stroke, asthma, organ damage and even death increase
  -in 2019, Paris recorded a high 42.6 degrees celcius and most of the 1435 heat-related deaths in France occured in Paris
• The earlier flowering of plants could negatively effect city residents with allergies

Question 7

Economic weaknesses of the UHI effect

Answer 7

• Increased strain on the supply of energy for cooling and air conditioning
• Increased demand of water by residents and buisinesses places extra strain on the water infrastructure

Question 8

Environmental weaknesses of the UHI effect

Answer 8

• Evapotranspiration rates will be higher, resulting in plants and trees absorbing an abnormal amount of water from the ground
• Increased risk of deteriorating historical monuments due to chemical weathering

Question 9

1) How can the UHI effect be managed?
MEW

Answer 9

• More urban parks as green spaces reduce temperatures in the area
• Electric cars emit no exhaust from a tailpipe and consequently less heat is emmited
• Whiter surfaces with higher albedos absorbs and stores less solar energy during the day, less heat emissions at night

Question 10

2) How can the UHI effect be managed?
UI

Answer 10

• Urban greening-planting trees and vegetation on buildingsprovides shade and can reduce building temps by 20-40 degrees
• Inceasing space between buildings-increases the rate at which heat can escape

Question 11

CASE STUDY UHI EFFECT- London,UK

Answer 11

• Heat strokes, respiratory issues, cardiovascular issues
• Solving the problem by planting trees so that theres more shade in the suture

Question 12

How might microclimates differ in LIC city to a HIC city?

Answer 12

• Denser populations and techmnology thats less environmentally efficient within LIC’s could mean they have more intense microclimates compared to that of a HIC