- A heat island is an area over which the air is warmer than the surrounding area.
- The reason for this difference is generally down to a chnage in land use.
- Urban areas tend to absorb for incoming radiation from the sun and re-emit it as heat: this is due to the dark surfaces and building materials.
- Heat islands are best measured in the late afternoon or early evening when the ground has had time to be heated and for it to heat the air above.
- Wind mixes the air and prevents heat islands forming.
Title: Is there a Heat
Island in Settlement ‘X’?
Hypothesis:
A
sentence that can be proven to be true or false: such as …
1.
Settlement
‘X’ has a ‘heat island’
2.
Air
temperature variations around the grounds in Settlement ‘X’ are due to
differences in ground cover.
Method:
(about 200 words)
What
data did you collect and how?
- Use annotated diagrams and photographs
wherever possible in your explanation.
Possible data that you might want to collect:
- air temperature (thermometer): best held at a fixed distance from the ground away from the body and not by the bulb!
- ground colour: This can be done by a simple 5 point scale where 1 is white and 5 is black; the darker the surface the higher the score OR you could be clever and use a luxmeter app on your iPad/smartphone
- Number of storeys: urban areas generally get taller as you approach the centre as the value of the land is higher.
- Distance from the centre: if you can locate a point which is the centre of your town or village, then temperature should decrease with distrance from this point.
- Ground cover: roads and pavements tend to absorb and re-emit more energy than vegetated areas.
Results:
(very little writing)
Graphs
and maps showing your data: (raw data should be put in the appendices at the
end of the write-up. You could use the
following methods:
- An isotherm map of the Settlement ‘X’
area (maybe on tracing paper over a base map/aerial photo: perhaps over a
‘land cover’ map)
- Graphs to show:
- All of the data stacked up for each
site (temperature, land cover, ground colour, wind speed, altitude (from
OS map or altimeter on GPS), number of storeys the buildings have, distance
from the nearest building (only an idea!)
- Scattergraphs comparing temperature
with a selection of variables to see if there is a relationship.
- A transect showing temperature and how
many buildings there are.
Analysis:
(about 300 words)
This section is very important as it shows the examiner how much geography you understand.
- Describe what your graphs and maps show in the results section.
- Are there any anomalies (odd readings) in your data?Can you explain them?
Conclusion and Evaluation:
(about 200 words)
- Is your hypothesis true or false?
- What other data could have been
collected to test the hypothesis better?
- Think about time, volume of data,
equipment and types of data collected.
