CUE 5 - Urban climate Flashcards
What is the urban heat island effect
The phenomenon or urban areas being warmer than rural areas
What are urban heat islands (UHI)
Urban areas with higher air temperature than the surrounding rural areas
Where are the highest temperatures found
In industrial areas and in the most densely built-up areas (CBD)
What are temperature sinks
Pockets of cool air above parks and bodies of water (like rivers and ponds)
What are plateaus?
Areas within the city with the same land use (like industry) generally have the same temperature
What are rapid changes in temperature reffered as?
Cliffs
When does temperature change rapidly
When land use changes (eg - from inner-city housing to CBD high rise buildings)
What are the 4 main causes of the UHI effect
- Absorption of heat by urban surfaces
- Air pollution
- Heat from human activity
- Less evaportranspiration
What surfaces absorb and store heat during the day
Concrete, brick and tarmac
What happens to these surfaces
Slowly release heat as long wave radiation - its more noticeable at night when it warms the air
What does air pollution from cars and factories do
Increases cloud cover over the city
WHat does this create
A pollution dome (layer of pollution over the city
What do these things do?
Trap outgoing heat radiation and reflect it back to the surface
Where does heat from human activity come from?
Cars, factories, offices, central heating. Air conditioning units and people themselves
What happens when it rains?
The water is quickly removed by drainage systems so there’s little surface water to evaporate
