LANDChapter 8
The CitySection 1
The
Urb
an-R
ural
Co
nnec
tion
URBANLand that is
covered mainly with buildings and roads is called urban land.
AKA “city”Has at least
5,000 people per square mile
RURALLand that contains relatively few people and large areas of open space.
The Urban-Rural ConnectionWhether people live in cities or in the
country, people are dependent upon resources produced in rural areas such as drinking water, fertile soil and land for crops, trees for wood and paper, and much of the oxygen we breathe.
People live where they can find the things that
they need and want, such as jobs, schools,
and recreational areas. For most people today, this means living in an
urban area.
UrbanizationThe movement of people from
rural areas to cities is known as urbanization.
People usually leave rural areas for more plentiful and better paying jobs in towns and cities.
Urbanization occurred rapidly in developed countries between 1880 and 1950. Now it is occurring most rapidly in developing countries.
Infrastructure:All of the things that a society builds for
public use….. Roads Sewers
Railroads Bridges Canals
Fire and police stations Schools Libraries Hospitals
Water mains Power lines
Urban Crisis!The lack of adequate infrastructure in
overpopulated cities throughout the developed and developing world has become so widespread that the term urban crisis was coined.
When more people live in a city than the city can support with jobs and infrastructure, living conditions deteriorate and unemployment increases.
According, to the United Nations, the crisis is so bad that almost ¼ of the world’s city dwellers could be homeless by the year 2020!
Heat IslandsCities both generate and trap more heat, and the
increased temperature in a city is called “heat island”Heat is generated by the infrastructure that makes a
city run: Roads and buildings absorb more heat than vegetation does They also retain heat longer Atlanta, GA is an example city that is a significant heat island
Scientists are beginning to see that heat islands can affect local weather patterns….Hot air rises over a city, cooling as it rises, and eventually produces rain clouds. Increased rainfall is a side effect of the heat island
Suburban SprawlRapid expansion of a city into a countryside
around the city is called Suburban Sprawl.Suburban Sprawl is development, characterized by
houses, malls, etc…that spreads out around cities.Much of this growth results in the building of
suburbs, or housing and associated commercial buildings on the boundary of a larger town.
People living in the suburbs generally commute to work in the city by car.
Many of these suburbs are built on land that was previously used for food production.
In 2000, more Americans lived in suburbs than in cities and the countryside combined.
Where We LiveUntil about 1850 people lived in rural areas. Many
were farmers and others managed the forests, worked in local mines or mills, or manufactured the necessities of life for a town.
The Industrial Revolution changed this pattern because new machinery made it possible for fewer people to operate a farm or mill. Also, better transportation allowed manufacturers to be located far from their customers.
So, thousands of jobs in rural areas were eliminated. Many people had to move to cities to find jobs.
As a result, urban areas grew rapidly during the 20th century and spread over more land.
As the human population grows, the resources of more rural land
are needed to support the population.
The main categories of rural land are: Farmland, rangeland, forest land, national and state
parks, and wilderness
Throughout history, we have sometimes managed these lands sustainably so that they will provide resources indefinitely
Other times, we have reduced their productivity by overusing or polluting them.
The condition of rural land is important because of the ecological services that are provided.
The resources that are produced by natural and artificial ecosystems are
called Ecosystem Services
Examples: Purification of air and water Preservation of soil and renewal of soil fertility Prevention of flood and drought Regulation of climate Maintenance of biodiversity Movement and cycling of materials Detoxification and decomposition of wastes Aesthetic beauty
The area of rural land needed to support one person depends on
many factors, such as the climate, the standard of living, and how efficiently resources are used.
Each person in a developed country uses the ecosystem services provided by about 8 hectares of land and water.
Many people in developing nations use less than 1 hectare of land per person.
In the United States, each person uses the ecosystem services from more than 12 hectares!!
1 hectare = 2.471 acres
Land Use PlanningLand-use planning is determining in
advance how land will be used-where houses, businesses, and factories will be built, where land will be protected for recreation, and so on…
Making land-use plans is complex and often controversial. The government requires detailed reports, the public gets to have input, and projects often affect large or environmentally sensitive areas.
Geographic Information System(GIS)
The most important technological tools for land-use planning involve using the geographic information system.
A GIS is a computerized system for storing, manipulating , and viewing geographic data.
GIS software allows a user to enter different types of data about an area, such as the location of sewer lines, roads, and parks, and then create maps with the data.
Creating a Land-Use Model
Planner (1): Wants to attract businesses & new
citizensDeveloper (2):
Interested in the right to build housing and a shopping center
Conservationist (3): Interested in preserving open space and
natural areasLaw Enforcer (4):
Ensures all laws are met
How We Use Land
Section 2
Primary Land-Use CategoriesRangelandForest LandCroplandParks and
PreservesWetlands,
mountains, deserts, and other
Urban landMining land
Land used to graze livestock and wildlife
Land used for harvesting wood, wildlife, fish, nuts and other resources
Land used to grow plants for food and fiber
Land used for recreation and scenic enjoyment and for preserving native animal and plants
Land that is difficult to use for human purposes
Land used for houses, businesses, industry, and roads
Land used to mine for minerals.
Forest LandsLand used for trees to be harvested to
provide products we use everyday, such as paper, furniture, and lumber and plywood for our homes.
There are many ecosystem services provided by forests, however, one of the most important is removal of CO2 from the air.
Harvesting TreesPeople use enormous amounts of wood.
The timber industry classifies forest lands into 3 categories 1. Virgin Forests: has never been cut 2. Native Forests: is planted and managed 3. Tree Farms: areas where trees are planted in
rows and harvested like other crops.
Harvesting Trees: The 2 most widely used
methods of harvesting trees are clear-cutting and selective
cutting.CLEAR CUTTING
The process of removing all of the trees from an area of land.
Clear cutting large areas destroys wildlife habitat and causes soil erosion.
SELECTIVE CUTTING
The process of cutting and removing only middle-aged or mature trees.
Selective cutting is more expensive than clear-cutting, but selective cutting is usually much less destructive.
Harvesting TreesDEFORESTATION is
the clearing of trees from an area without replacing them.
Forests are cleared to convert the land into farmland.
People also clear forests to make space for roads, homes, factories, and office buildings.
REFORESTATION is the process by which trees are planted to re-establish trees that have been cut down in a forest land.
In some places, surprisingly, reforestation is happening faster than trees can be cut down!
RangelandsLand that supports different vegetation
types like grasslands, shrub lands, and deserts, and that is not used for farming or timber production.
The most common human use of rangeland is for grazing of livestock.
Much of the rangeland in the U.S. is degraded, and the Public Rangelands Improvement Act of 1978 was enacted to reverse this trend and improve land management practices.
More About Rangelands
Some experts predict that current trends in population growth will necessitate a 40% increase in food production from rangeland between the years 1977 and 2030!
Most damage to rangeland comes from overgrazing When an area is overgrazed, much of the grass is destroyed
and the root system decays…so the roots are less efficient at protecting the soil from wind and water erosion
If a prolonged drought plagues an overgrazed area before other plants can take over, the land may become too degraded and cannot recover…this process is called desertification….and converts rangeland to wasteland!
FarmlandsLand that is used to grow crops & fruitsThe U.S. contains more than 100 million
hectares of prime farmland, however, in some places, urban development threatens some of the most productive farmland.
In 1996, the U.S. government established a national Farmland Protection Program to help state, county, and local governments protect farmland in danger of being paved over or otherwise developed.
We will discuss more on farmland in Chapter 9!
Mining A surprising amount of land is used
for mining minerals (a solid substance found in nature and consists of a single element or compound like salt, gold, silver)
2 common methods for extracting minerals from earth: Open-pit mining
Machines are used to dig large holes in the ground and remove the ore (mineral containing rock)
Sand, gravel, and building stone are mined in this way
Strip mining Huge bulldozers and other machines are
used to clear away large strips of Earth’s surface.
The rock phosphorite, which is a raw material used to make fertilizers and phosphate chemicals, is often mined in this way
Effects of MiningExtracting minerals from the Earth causes
environmental damageThe most obvious being disruption of the land
surface and the ugly piles of waste materials left behind
When large areas of vegetation are cleared, wildlife habitat is lost, and the area’s natural ecosystem is disrupted
Mines in the US collectively produce more waste than all American cities and towns combined. Some wastes are dangerously toxic.
Responsible MiningOne way to reduce damage from mining is to
require mining companies to restore mined land to the condition it was in before mining began…called reclamation. Environmental laws in the US now require companies to
reclaim mining sties on public land. Some states also have laws that require reclamation on private land
Another way to reduce the destructive effects of mining is to reduce the need for more minerals By recycling existing products made from minerals such as
iron, copper, and aluminum, we not only save energy, water, and money, but also reduce the pollution caused by additional mining and processing operations.
Public Land in the United
States
Section 3
Parks and PreservesYellowstone was our first national park because
Congress took an interest in protecting this land from development in the 1870s because a group of explorers approached them with concern.
Today, the U.S. has about 55 national parks. If you are a citizen, you share ownership of these lands.
Benefits of protected areas: protects species & unspoiled forests and provides recreation for people.
Threats to protected areas: when people visit, they leave behind litter, cause traffic jams, etc…
This Land Belongs to You and Me…
40% of all the land in the US is publicly owned
Public lands are managed by federal, state, and local governments…the chief landowner is the federal government
Most of the land that the fed gov owns is in the West and in Alaska
If you are a US citizen, you are a partial owner of these lands
Wilderness
According to the Wilderness Act of 9164, wilderness is an area in which the land and the ecosystems it supports are protected from all development.
Wilderness areas are found within several of the nation’s public land systems…so far, 657 regions covering more than 42 million hectares (104 million acres) have been designated as wilderness.
These areas are open to hiking, fishing, boating (w/out motors), and camping.
These areas also provide ecological benefits such as habitats for wild plants and animals and serving as outdoor classrooms where people can learn more about the natural world and how it works.
“People Control”in Wilderness Areas
To protect wilderness from damage, limits have been set in some areas for the number of people who can hike or camp at any one time. Federal agencies now require people who want to sue the
most popular areas to apply for wilderness permits. A permit system enables the agency to regulate the number of people inside national parks at a given time
Certain areas have also been designated as no camping zones and are being patrolled by rangers in vulnerable areas.
Volunteer programs are now active in helping pick up trash and building trails.
Finally, new education programs, such as the Forest Service’s Tread Lightly program, are also being implemented to help people better understand and reduce their impact on the natural world.