A Sub continental Region
South-West USA
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South-West USA
South-West USA
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California to Texas 3000km
Specific types of economic development
The information technology industry
The aerospace industry
The oil industry
American South-West
American South-West
• Summary of the South-West:
– The South-West is a region of arid plains
and Spanish forts, the atmosphere of the
‘old West’, oil and cattle, a ‘can-do’ culture,
big money and brash cities
Physical Processes
• Variety of landscape and topography
• California: The Coastal Range, Central
Valley and Sierra Nevada
• East of Sierra Nevada: intermontane
basin and plateaus of the Nevada
• The Great Basin of Nevada is the
largest basin of inland drainage in the
USA
Physical Processes
• The Rocky Mountains (difficult for 19th
century Europeans to cross)
• The Texas plains take the traveller
through Texas and finally to the Gulf of
Mexico
The Colorado River
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Main drainage channel
Reddish colour of its silt
Colorado means ‘coloured’ in Spanish
Before dams were built laden with silt
Locals claimed that its waters were too
thick to drink and too thin to plough
• Spring floods and Summer droughts
The Colorado River
• Dams built to control the flow of water
• 20th century
• Essential source of water for the people
of SW USA
• 22million people in California, Nevada
and Arizona depend on the river
The Colorado River
• Irrigation for 400,000 ha in USA and
20,000 ha in Mexico
• Lake Mead, behind the Hoover Dam is a
major tourist attraction
The Colorado River
• Ecology of the region is affected by the
large dams
• Silt that fed the river delta is now
accumulating in reservoirs
• The delta at the mouth of the river is
longer growing
• Nutrients supplied by sediments are no
longer deposited in the Gulf of California,
decline of fish stocks
The River Delta
A Delta:A river delta is a
landform that is formed at the
mouth of a river, where the river
flows into
an ocean, sea, estuary, lake,
or reservoir. Deltas are formed
from the deposition of
the sediment carried by the river
as the flow leaves the mouth of
the river. Over long periods of
time, this deposition builds the
characteristic geographic
pattern of a river delta.
Landscape
Climate
Climate
• Much is arid or semi-arid (low precip)
• Much of the region precipitation below
250mm
• Southern California, Arizona and New
Mexico arid or semi-arid
• Death Valley highest daytime
temperature of the western hemisphere
in Southern California
Climate
• Mountains have a huge influence on
temperature and precipitation
• Sierra Nevada has snow-capped peaks in N.
California
• Mountains, distance from the sea and local
winds modify the temperature of the region
• Most of the region in the Sun Belt 2500 hours
of sunshine per year (Similar to S. Italy)
Economic Processes
Primary Activities
Primary Activities
• Major differences in agriculture
• Due to climate, soil differences, local
markets and availability of water for
irrigation
• Family farms still important
• Agri-companies taking over
• Agricultural practices in the region
among the most modern in the world
Primary Activities
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Industry is market focused
Fully industrialised
Ultra-modern machinery and technology
Cattle ranchers use helicopters to
survey their herds
• Rice farmers in California use laser
technology to level fields for irrigation
Primary Activities
• Ranching:
– Occupies a large portion of the agricultural
land of the region
– Suited to semi-arid regions that are too dry
for cereals
– Small groups of workers who retain the
‘cowboy’ skills of the past
– Cattle stocking rates are lo because of
sparse vegetation
Ranching
http://www.youtube.com/watch?v=jzE97WxxAz8
Primary Activities
• Ranching is known as extensive farming
• Low output per hectare high output per
worker
• Cattle born and reared in western range
lands and later sold fort fattening to
feedlots of California, Texas and the
Corn Belt further east
• Vast feedlots dot the agri landscape
Feedlots
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Agri companies
Can afford technology required
Intensive cattle fattening
Migrants from Mexico supply most of
the agri labour today
Irrigated Agriculture
• Central Valley California, Gila Valley
Arizona and the Gulf coast of Mexico
have intensive agriculture
• Requires irrigation
• Citrus fruits, vegetables and salad crops
(high value crops) for urban market
• Rice grown on 2000km2 of heavily
irrigated land in Caifornia
Pivot Irrigation
Agriculture
• Irrigation is responsible for the boom in
agriculture
• Also for the rapidly rising population of recent
decades
• Irrigation has turned vast deserts into oases
of green (vast quantities of perishable foods)
• Texas has highest rainfall (great agri state)
• Apart from cattle the state produces maize,
wheat and Soya beans