Transcript THE GREAT PLAINS AND PRAIRIES

THE GREAT PLAINS AND
PRAIRIES
(CHAPTER 12)
INTRODUCTION
• The Great Plains and Prairies are outlined on p. 267.
• Regional Perspectives
– Coronado explained, "this region is the best I've seen
for producing the crops of Spain - the land is flat, soil is
black, and is well watered with springs and rivers.”
– Early 1800s - perceived to be wholly unfit for cultivation
and uninhabitable for people depending on agriculture
– Mid 1850s - labeled the "Great American Desert."
• Historically - drastically different perceptions of the
region's physical geography and its potential for
settlement
GREAT PLAINS AND
PRAIRIES
PHYSICAL GEOGRAPHY
• Terrain
 Elevation rises gently from east to west (500 meters
to 1500 meters).
 Southern half of the region has unvaried
topography
 Northern half is more variable and is characterized
by “badlands.”
 Very irregular topography resulting from wind and water
erosion of sedimentary rock.
 Widespread on the Missouri Plateau between northern
Nebraska and the Missouri River
 Best example in western South Dakota.
GREAT PLAINS &
THE PRAIRIES
PHYSICAL GEOGRAPHY
• Vegetation
 Grasses are taller and more dense in
the East and shorter and relatively
sparse in the West.
 Much of the grasses have intricate root
systems, which were difficult to plow
and often required "Bonanza teams" of
about 20 animals to break the sod.
PHYSICAL GEOGRAPHY
• Precipitation
 Most precipitation in the region results from the
interaction of air masses.
 Amounts vary from 10-40 inches annually,
decreasing from east to west.
 About 75% of the precipitation falls from April
through August.
 Major droughts have occurred in 20 year cycles.
 Significant droughts in the 1890s, 1910s, 1930s,
1950s, and 1970s
PRECIPITATION VARIABILITY
PHYSICAL GEOGRAPHY
• Temperatures
 Region experiences extremes in
temperatures because of its continental
climate
 Fluctuations increase from south to
north.
 Northern Texas has over 240 frost free
days each year, whereas Canada's
prairies experience less than 90.
PHYSICAL GEOGRAPHY
• Winds- serve as a mixed blessing to
the region.
 In late spring and summer, wind velocities
in the central and northern Plains are
among the highest in North America.
 Ensures maximum efficiency for the
region's windmills.
 High rates of evaporation and transpiration
may minimize the effects of precipitation.
WIND POWER
“Certainty Rating of the Wind Resource”
PHYSICAL GEOGRAPHY
 Chinooks - warm, dry, winter winds from the Pacific
that bring welcomed relief during the winter months
 Blizzards - characterized by snow, wind, & intense
cold
 Occur when cold polar air masses push south along the
Rockies, and can last for several days
 Tornadoes - pose a significant regional hazard.
 Great Plains experience far more tornadoes annually than
any other comparable area in the world.
 Parts of Texas, Oklahoma, and Kansas encounter 200 300 per year, largely concentrated in the spring and early
summer.
TORNADO FREQUENCY
EARLY SETTLEMENT PATTERNS
• Plains Indians
 Pre-European occupation was limited.
 Hunting for buffalo was the primary activity
 Semi-permanent settlements were situated
mainly along streams.
 The Indians greatly improved their mobility
once the early Spanish explorers left behind
horses.
EARLY SETTLEMENT PATTERNS
• Early Problem Areas




Average annual rainfall <<< that found in the East
Considerable variation in annual rainfall
Violent storms - high winds, hail, and tornadoes
Winter blizzards intensified the cold and blew snow
into deep, impassable drifts.
 The hot, dry winds of summer routinely carried
away topsoil in clouds of dust.
 Sparse natural water supply to support tree
growth, so no wood for building, fuel, fencing, etc.
 The ground was difficult to plow.
EARLY SETTLEMENT PATTERNS
 Settlement had initially halted along the eastern
margins.
• Permanent Settlement was initially inspired by
the Homestead Act.
– Passed in 1863
– Gave 160 acres of land free to each settler
– Encouraged settlement of the Great Plains.
 1867-1885- ranching was a viable alternative.
 Late 1870s- barbed wire, lumber, and windmills
helped to overcome environmental constraints.
AGRICULTURE
•
•
Large scale and machinery intensive
Wheat
 Winter wheat
 Grown from Northern Texas to Southern
Nebraska.
 Spring wheat
 Areas with severe winters and cool summers
 Located from central South Dakota to the south
central Prairie Provinces of Canada.
 U.S. and Canada are the world's leading exporters
 Kansas and North Dakota lead all U.S. production.
 Saskatchewan is by far Canada's largest producer.
AGRICULTURE
• Shipment Patterns
 Most Canadian wheat goes to Winnipeg
then to Thunder Bay for shipment
across the Great Lakes. In the West, it
goes to Vancouver by rail and is then
shipped by sea.
 U.S. wheat shipments travel across the
Great Lakes or down the Mississippi
River.
AGRICULTURE
• Key Terms
 Migrant Labor
 The term should not to be confused with migrant
workers who harvest crops in other regions.
 These workers comprise large crews that use
numerous combines and trucks.
 They travel from Texas in early June and follow
the wheat harvest north into the Prairie Provinces
 Accounts for about four months total work.
AGRICULTURE
 Key Terms (continued)
 Sidewalk Farmers are those farmers who
live in town and travel to their various
acreages nearby.
 Suitcase Farmers are farmers who live far
from their fields and only visit them
occasionally, approximately four or five times
a year, as in the case of those who own
large wheat farms.
AGRICULTURE
• Other Crops
 Barley - important in the Canadian province
of Alberta.
 Sorghum - used for stock feed and grown
throughout the hot, dry margins of the plains
 Cotton - a dominant crop in Texas
 Oats - grown throughout the Northern Plains
area
 Cattle
OGALLALA AQUIFER
GROUND WATER
“OVERDRAFT”
ENERGY RESOURCES
• The Panhandle Field of Northwest Texas,
Oklahoma, and Kansas is the world's leading
supplier of natural gas.
 All three states are major petroleum
producers, along with Wyoming and Alberta.
 Coal is abundant in Wyoming, which may be
the leading producer in the U.S. by the year
2002. Lignite, a brownish, soft coal is also
readily available in North Dakota.
THE GREAT PLAINS AND
PRAIRIES
(CHAPTER 12)