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