Download - Land Use
Land Use
Ch 14 & 15
Land Use Categories• Urban• Agricultural• Forests• Parks and protected
Urban• For the first time, more people live in cities than on
rural land• Mass urbanization continues– Movement to cities from rural lands
• Advantages:– Jobs more plentiful and centrally located– More efficient use of land per person• “vertical housing”• Infrastructure reaches many per given area
Problems with Urbanization
• Unplanned growth results in urban sprawl• Urban lands spread into arable land• Growth exceeds capacity of infrastructure, leading to
urban crises– When population growth exceeds governments’ abilities to
build water, sewer, sanitation, power, roads, schools • Development onto marginal lands– Encroaching into farmland, or too close to other natural
features, such as cliffs or the Everglades.• Higher strain on surrounding rural land to serve urban
needs (“ecosystem services”)• Higher pollution rates• Heat islands (see p 386)
Urban Heat IslandAtlanta, GA
http://earthobservatory.nasa.gov/IOTD/view.php?id=7205
http://www.law.georgetown.edu/clinics/hi/ClimatePolicy.htm
Sometimes Infrastructure can’t grow as fast as population, resulting in poor sanitation, unhealthy living conditions
http://www.laputan.org/mud/
http://www.mole.my/content/mail-finally-arrives-rio-favela
Called “urban crisis”
Open sewer in shanty town
http://www.indymedia.ie/article/94825
Land Use Planning• Complex and can be
controversial– Many competing interests: – Developers,
environmentalists, current residents, retail owners
• Geographic Information Systems (GIS)– Multilevel maps used to store
many layers of information for effective planning
Land Use Planning
• Mass Transit – publicly subsidized people movers.– Integral part of effective land use plan– Saves on infrastructure costs
– These make most sense where population density is highest
Miami Light RailPittsburgh Subway System
Mass Transit in Atlanta
Urban Open Spaces
• Provide some ecosystem services, – Recreation– Air cooling– Air exchange
• Atlanta Greenway – under way• http://beltline.org/about/the-atlanta-beltline-
project/similar-projects/the-midtown-greenway-mn/
• Chattahoochee River Trails• etc
Agricultural• Crops – Arable land = land that can be planted for crops– Only about 10% of land surface on earth is arable– Shrinking daily, due to urbanization, topsoil erosion and
desertification• Range and pasture– Soil not rich enough for crops, but animals can “turn it into
food”• Livestock– Including CAFO’s
• Concentrated Animal Feed Operations• Aquaculture– Fish farming (includes shellfish)– Hydroponics
Crops• Farming methods for growing crops have become
more and more efficient to feed the growing population– More food produced for each acre of land = higher
yield• Strains on crops have required more use of
chemical fertilizers, pesticides and herbicides• Monoculture depletes soil of nutrients, creating
need for inorganic chemical fertilizers• Pesticides and herbicides create resistant insects
and weeds, creating the need for increasingly stronger poisons
Topsoil
• surface layer of land that contains lots of nutritious organics, mixed with inorganic particles, that holds moisture and that plants grow well in
• Topsoil erosion – arguably the greatest environmental problem, next to population growth
• Created dustbowl of ‘30’s
http://en.wikipedia.org/wiki/Dust_Bowl
http://en.wikipedia.org/wiki/Dust_Bowl• The Dust Bowl, or the Dirty Thirties, was a period of severe
dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1936 (in some areas until 1940).
The phenomenon was caused by severe drought coupled with decades of extensive farming without crop rotation, fallow fields, cover crops or other techniques to prevent wind erosion.[1]
Deep plowing of the virgin topsoil of the Great Plains had displaced the natural deep-rooted grasses that normally kept the soil in place and trapped moisture even during periods of drought and high winds.
Dust Bowl – topsoil erosionDuring the drought of the
1930s, without natural anchors to keep the soil in place, it dried, turned to dust, and blew away eastward and southward in large dark clouds. At times the clouds blackened the sky reaching all the way to East Coast cities such as New York and Washington, D.C. Much of the soil ended up deposited in the Atlantic Ocean, carried by prevailing winds, which were in part created by the dry and bare soil conditions.
These immense dust storms—given names such as "Black Blizzards" and "Black Rollers"—often reduced visibility to a few feet (around a meter). The Dust Bowl affected 100,000,000 acres (400,000 km2), centered on the panhandles of Texas and Oklahoma, and adjacent parts of New Mexico, Colorado, and Kansas.[2]
Dust Bowl – topsoil loss• Millions of acres of farmland became useless, and
hundreds of thousands of people were forced to leave their homes;
• many of these families (often known as "Okies", since so many came from Oklahoma) migrated to California and other states, where they found economic conditions little better during the Great Depression than those they had left.
• Owning no land, many became migrant workers who traveled from farm to farm to pick fruit and other crops at starvation wages. Author John Steinbeck later wrote The Grapes of Wrath, which won the Pulitzer Prize, and Of Mice and Men, about such people.
http://en.wikipedia.org/wiki/The_Grapes_of_Wrath
Topsoil erosion
http://www.swac.umn.edu/classes/soil2125/doc/s10chap3.htm
Sheet erosion
http://www.civil.ryerson.ca/stormwater/menu_5/index.htm
Sheet and Rill Erosion
http://www.geo.fu-berlin.de/fb/e-learning/geolearning/en/soil_erosion/types/index.html
Gully erosion• Rills can expand into gullies
Gully Erosion• Providence Canyon, GA• Created entirely from land mismanagement• Cotton had been farmed here
Providence Canyon
Topsoil erosion factsfrom Cornell University study
The study, which pulls together statistics on soil erosion from more than 125 sources, reports:
• The United States is losing soil 10 times faster -- and China and India are losing soil 30 to The United States is losing soil 10 times faster -- and China and India are losing soil 30 to 40 times faster -- than the natural replenishment rate. 40 times faster -- than the natural replenishment rate.
• The economic impact of soil erosion in the United States costs the nation about $37.6 billion each year in productivity losses. Damage from soil erosion worldwide is estimated to be $400 billion per year.
• As a result of erosion over the past 40 years, 30 percent of the world's arable land has As a result of erosion over the past 40 years, 30 percent of the world's arable land has become unproductive. become unproductive.
• About 60 percent of soil that is washed away ends up in rivers, streams and lakes, making waterways more prone to flooding and to contamination from soil's fertilizers and pesticides.
• Soil erosion also reduces the ability of soil to store water and support plant growth, Soil erosion also reduces the ability of soil to store water and support plant growth, thereby reducing its ability to support biodiversity. thereby reducing its ability to support biodiversity.
• Erosion promotes critical losses of water, nutrients, soil organic matter and soil biota, harming forests, rangeland and natural ecosystems.
• Erosion increases the amount of dust carried by wind, which not only acts as an Erosion increases the amount of dust carried by wind, which not only acts as an abrasive and air pollutant but also carries about 20 human infectious disease organisms, abrasive and air pollutant but also carries about 20 human infectious disease organisms, including anthrax and tuberculosis. including anthrax and tuberculosis.
http://www.news.cornell.edu/stories/march06/soil.erosion.threat.ssl.html
desertification
Loss of topsoil results in land drying and desert expanding into it.
Desertification: dust storm over Mediterranean Sea
http://amazingdata.com/world-day-to-combat-desertification-and-drought-special/
Desertification
http://en.wikipedia.org/wiki/File:Desertification_map.png
Most vulnerable areas are in red
Salinization• The accumulation of salts in the soil• Common problem in Arizona/California, where
soil is naturally salty • And rainfall is low• Irrigation with salty groundwater or surface
water• Salts get left behind
Solutions include:
http://amazingdata.com/world-day-to-combat-desertification-and-drought-special/
Planting tree lines to try to break up the wind
Topsoil solutions
• Contour farming and strip cropping• Crop rotation, including legumes• Letting fields “lie fallow”• No-till farming• Cover crops• Drip irrigation systems• Terracing• Enriching soil with compost
http://kids.britannica.com/comptons/art-56029/An-aerial-view-of-farmland-in-Minnesota-shows-the-unique
Range and Pasture Land
• Topsoil too thin to support crops
• Cattle and other livestock can graze and turn “inedible plants” into food
• Overgrazing becoming a problem– Plants cannot recover
fast enough http://www.kkl.org.il/kkl/english/main_subject/curb%20global%20warming/livestock%20grazing-combats%20or%20spreads%20desertification.x
Forests
Three types:• Virgin – never been cut• Native – forest that is planted and managed• Tree farms – areas where trees are planted in
rows and harvested like crops – Georgia has a huge industry of tree farms
http://jerrydgreer.wordpress.com/2008/04/19/joyce-kilmer-memorial-forest-nantahala-national-
forest-nc/
http://www.kynd.com/~finest/retail.htm
Loblolly tree farm in Georgia
Notice:Notice:•MonocultureMonoculture•No growth on forest floorNo growth on forest floor•No biodiversityNo biodiversity
http://www.flickr.com/photos/41460075@N08/4147750657/sizes/o/in/photostream/
Used for pulp and paper industry
Forests: Deforestation
Clear cutting• removing ALL the trees in
an area• Cheaper• More erosion
Selective cutting • cutting only middle-aged or
mature trees– More eco-friendly– Preserves biodiversity– Decrease erosion and fire
danger
http://www.thecroc.org/crocblog/2009/10/clearcut-for-the-climate/ http://pdsblogs.org/
pdsapes812/2012/01/06/responsible-forest-management/
Forests: Deforestation
• Much deforestation of virgin forests is done to clear for agricultural uses – grazing and croplands
http://www.time.com/time/health/article/0,8599,1904174,00.html
Forests
• Reforestation – Planting trees where they have been recently
removed
• “Afforestation” – Planting trees where they haven’t been for over
50 years
• New England now contains more forest than it did a century ago
Forests
Benefits:• Carbon sink – trees take up and store carbon
dioxide from the atmosphere• When trees are burned in clear cutting, all the
Carbon stored in trees is released at once as CO2
(combustion)
Parks and Preserves
• Areas set aside to protect wildlife and habitat• WildernessWilderness Areas are areas in which the land
and the ecosystem it supports are protected from ALL exploitation
• Open to hiking, fishing, boating (without motors) and camping
• No road building or structures• National Parks are not wilderness areas
Wilderness areas and national parks maps
• http://www.wilderness.net/map.cfm• http://www.nps.gov/hfc/carto/nps-map-
zoomify/nps-wall-map.html
Parks and Preserves - threats
• Overuse– Erosion– Trash– Degradation of area for wildlife
• Many state and nationally held areas allow– Controlled deforestation– Fracking and oil drilling, etc
CAFO’s
• Concentrated Animal Feed Operations• Most livestock are raised this way in US and
other developed countries• Pollute water ways and concentrated wastes
can seep into groundwater• Mistreatment of animals• Animals eat only corn and grains – no free
range
CAFO chickens• http://www.jehovahjirehfarm.com/chicken.php
Non-CAFO
CAFO cows
http://oklahomafarmreport.com/wire/cattlenews/5279988_TCFAReactCAFORegs_202519.php
CAFO pigs
• Notice the cage is not large enough for them to lie down
http://www.enlightenamsterdam.com/veganism.html
CAFO manure management
http://www.enlightenamsterdam.com/veganism.html
Note that manure Note that manure must be carefully must be carefully managed to avoid managed to avoid leaching into nearby leaching into nearby waterways or waterways or groundwatergroundwater