TWO EXTREME ENVIRONMENTS
- Cold and high-altitude environments (polar, glacial areas, periglacial areas, high mountains in non-tropical latitudes)
- Hot, arid environments (hot deserts and semi-arid areas)
Distribution refers to the way something is spread out or arranged over a geographic area. The concept of distribution can be applied to nearly everything on Earth, from animal and plant species, to disease infections, weather patterns, and man-made structures.
Many of the things geographers study are found in some places, but not in the others. This means these patterns occur in certain distributions over the Earth's surface. Geographers look for and try to explain any patterns that may occur. "Distribution" refers to the way something is spread out or arranged over an area. Recognizing distributions on a map is a starting point for many geographic studies. Geographers look for and try to explain any patterns that may occur.
Some distributions can be seen visually. The number of barns in a farming community can be seen from an airplane, for example.
Visual information is not always accurate or available, however. Areas may be too big to see, and some areas are not visible at all. These patterns of distribution need to be put on a map. World population is a good example of information that has to be mapped. Geographers can’t count the number of people in an area from the air. They rely on many types of information, such as census data, to determine the distribution of people in a certain area.
To understand distribution patterns, it is important to understand other factors, such as climate, landforms, and vegetation. For example, the human population distribution shows very few people living in Asia’s arid Gobi Desert. The desert offers few resources important for survival.
EXPLAINING GLOBAL DISTRIBUTION OF COLD AND HIGH ALTITUDE ENVIRONMENTS
Cold and high-altitude environments are generally found along constructive plate margins, where fold mountains form, or polar regions. Mountainous regions have a high elevation, where atmospheric pressure is lower which causes lower temperatures. The sun's rays are received more easily however more solar radiation is reflected due to the high reflectivity of snow. At higher latitudes less heat penetrates the atmosphere as it is thicker and spread across a greater area.
EXPLAINING the GLOBAL DISTRIBUTION OF HOT, ARID ENVIRONMENTS
Hot, arid environments are found in the tropics. These areas receive direct sunlight in summer and winter. Hadley cells in the atmosphere also cause aridity as the warm moist air rises from the equator. This condenses and precipitates and the cooler air sinks over the tropical latitudes. The air is drier as cool air cannot hold as much moisture. The air then heats as it spreads over tropical regions and rises again. Hot, arid climates can also be found in rain shadows, mountainous regions with arid areas behind them. The mountains cause relief rainfall and then the dry air blows across the landscape drying it out.
Add the names and descriptions of the two extreme environments to your notes.
Read about geographic distribution. Add 5 bullet points to your notes.
On a blank world map, draw the distribution of each environment. Use different colours. Add a title and a key.
Read about the reasons for this distribution using the description above and p 80 of your study guide.
Annotate your world map with clear labels explaining the distribution observed.
Colour code your labels to indicate "Cold, high altitude" or "Hot, arid".
EXPLAIN HOW THESE CHARACTERISTICS PRESENT CHALLENGES FOR RESOURCE DEVELOPMENT AND HUMAN HABITATION
Download 'The Little Book of Permafrost' from the iBooks store.
Read pp 4-6
Explain what permafrost is
Draw a labelled diagram