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IB World Geography
September 9, 2009 Population Demographics, Cont.
humanCultural ecology is the geographic study of human-environment interactions. Some 19th century
geographers argued that human actions were scientifically cause by environmental conditions an approach
called environmental determinism Modern geographers reject this approach in favor of Possibilism
arguing that the physical environment may limit some human actions, but people can adjust to their
environment. People choose a course of action among alternatives in the environment, and endow the
physical environment with cultural values by treating it as substances for use, a collection of resources For
example, the climate of any location influences human activities, especially food production.
Human and Physical Factors
Human geographers use this cultural ecology, or human-environment approach, to explain many global
issues People can adjust to the capacity of the physical environment by controlling their population
growth adopting new technologies consuming different foods migrating to new locations and other
actions. A people’s level of wealth can also influence its attitudes toward modifying the environment
Modern technology has altered the relationship between people and the environment.
Physical Processes: Climate
Geography students need some familiarity with global environmental processes to understand the
distribution of human activities. C limate is the long-term average weather condition at a particular location.
Geographers frequently classify climates according to a system developed by German climatologist Vladimir
Koppen which divided the world’s climate into 5 zones: Tropical (Equatorial), Dry (Arid), Temperate,
Cold(Snow) and Pola r . The climate of a particular location influences human activities, especially production
of the food needed to survive.
Physical Processes: Vegetation
Some form of plant life covers nearly the entire land surface of the Earth. Earht’s land vegetation includes 4
major forms of plant communities, called biomes forest savanna grassland and desert Their location
biomes: forest, savanna, grassland,
and extent are influenced by both climate and human activities Vegetation and soil, in turn, influence the
types of agriculture that people practice in a particular region.
Physical Processes: Soil
Soil the material that form son the Earth’s surface, is the thin interface between the air and the rocks. Not
merely dirt, the soil contains nutrients necessary for successful growth of plants, including those useful to
humans. The U.S. Comprehensive Soil Classification System divides global soil types into 10 orders. The
orders are subdivided into suborders, great groups, subgroups, families, and series. More than 12,000 soil
types have been identified in the U.S. alone. Two basic problems contribute to the destruction of soil: erosion
and depletion of nutrients
IB World Geography
September 9, 2009 Population Demographics, Cont. Physical Processes: Landforms
Geographers find that the study of Earth’s landforms—a science known as geomorphology—helps to
explain the distribution of people and the choice of economic activities at different locations. Geographers
use topographic maps to study the relief and slope of localities. Relief is the difference in elevation between
any two points. It measures the extent to which an area is flat or hilly.
Space: Distribution Features
Geographers think about the arrangements of people and activities found in space and try to understand
why those people and activities are distributed across space as they are. Distribution is the arrangement of
a feature in space. Geographers identify 3 main properties of distribution across Earth: density
concentration and pattern
Density is the frequency with which something occurs in space. Arithmetic density which is the total
number of objects in an area is commonly used to compare the distribution of population in different
countries. It involves 2 measures: the number of people and the land area A large population does not
necessarily lead to a high density. Physiological density is the number of people per unit of arable (suitable
for agriculture) land The number of farmers per unit of area is called agricultural density A more recent
measurement of density is housing density which is the number of dwelling units per area.
Concentration is the extent of a feature’s diffusion over space. Clustered objects are close together,
dispersed are far apart.
Pattern is the organi zation of features within a given area. ...
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