APES Unit 5 - land and water use

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Urbanization

the increase in people living in city areas

Urban sprawl

The change in population distribution from places with high population density to low density places like suburbs and rural areas

• causes environmental issues

Urban

densely populated areas such as cities

Rural

sparsely populated areas such as the countryside

Resource depletion

• a result of urbanization

• urban areas imbibe more water for their personal use

• fossil fuels are burned extensively for cars and power generation

• leads to more CO2 in the atmosphere

Saltwater intrusion

• affects the hydrologic cycle

• a result of urbanization

• salt water moves from the oceans to the groundwater supplies, causing issues for coastal cities

Flooding

• a result of urbanization

• cities have more impervious surfaces (roads, buildings, etc) that don’t let water reach the soil

  • also impacts the recharge of aquifers

  • causes increased runoff, impacting the hydrologic cycle and causing this result

Mass transit systems

• a solution to urbanization

• reduces CO2 by lessening the amount of vehicles on the road

Emissions inspections

• a solution to urbanization

• ensures that CO2 levels in cars are at a reasonable level

Increase water infiltration

• a solution to urbanization

• replacing traditional pavement with a more permeable material will do this

Plant more trees

• a solution to urbanization

• more CO2 can be converted back to oxygen

• another similar idea is creating more green space in urban areas in general - think live, work, play areas

Building restrictions

• a solution to urbanization

• rules created for buildings to grow “upward” instead of “outward,” limiting the amount of soil space they take up

Tragedy of the commons

A psychology term—a phenomenon where there’s unlimited access to a common resource, but people will selfishly deplete the resource for themselves instead of sharing it for the good of the people.

Ecological footprint

An individual or society’s resource demand versus waste production

Sustainability

The human use of resources without depleting them for future generations

Environmental indicators

• guide humans to sustainability based on how well they are doing

• include:

  • biological diversity

  • food production

  • average global surface temperatures

  • CO2 concentrations

  • human population growth

  • resource depletion

Sustainable yield

• measures sustainability

• this is the amount of a renewable resource that can be taken without reducing the available supply

Sustainable agriculture

• incorporates several strategies to keep soil intact and healthy

• ensures future growth of plants within the industry

Prevention of soil erosion

• the primary goal of soil conservation / sustainable agriculture

• methods include

  • contour plowing

  • windbreaks

  • planting perennial crops (don’t need to be replanted to grow each year)

  • terracing

  • no-till agriculture

  • strip cropping

Soil fertility

• a way to conserve soil / practice sustainable agriculture

• crop rotation helps with this by reducing the risk of nutrient depletion

• addition of green manure or limestone adds vital organic nutrients to the soil

Prevention of overgrazing

• a way to conserve soil / practice sustainable agriculture

• regular rotation of livestock (rotational grazing) between different pastures helps this

Sustainable forestry

Maintains forests, which provide many ecosystem services and goods

Deforestation

• an issue preventing sustainable forestry

• the cutting down of trees to clear area for towns, buildings, etc

• solutions include:

  • reforestation

  • using and buying wood that has been harvested by ecologically sustainable forestry techniques (ethically sourced)

  • reusing wood

Pathogens and pests

• an issue preventing sustainable forestry

• diseases and organisms that destroy forests

• solutions include:

  • Integrated Pest Management (IPM)

  • the removal of diseased trees, preventing further disease and destruction

Fire

• an issue preventing sustainable forestry

• a natural disaster (or man made) that burns down trees

• solutions include:

  • prescribed burns can remove flammable underbrush and are necessary to reduce natural occurrences of this disaster

Grade

the percentage of metal content in an ore, affects the environmental impacts of mining

• a higher version of this gets mined first because it is accessible

• a lower version of this takes more energy, fuel, and water to reach and extract, causing:

  • land disruption

  • mining waste

  • pollution

Extraction

the greatest danger in mining, instead of the actual use / burning of the mined material. additionally, processing and conversion of products are equally damaging.

Effects of mining

Due to extraction and exploration, we get these.

• Includes:

  • Land disturbances

  • Mining accidents

  • Health hazards

  • Mine waste dumping

  • Acid mine drainage

  • Oil spills / blowouts

  • Noise

  • Ugliness

  • Heat

Effects of processing

Due to transportation, purification, and manufacturing, we get these.

• Includes:

  • Solid waste

  • Radioactive material

  • Air, water, and soil pollution

  • Noise

  • Health and safety hazards

  • Ugliness

  • Heat

Effects of use

Due to transportation or transmission of mined products to individual users, the eventual use of them, and the discarding of them, we get these.

• Includes:

  • Noise

  • Ugliness

  • Thermal water pollution

  • Air, water, and soil pollution

  • Solid and radioactive waste

  • Safety and health hazards

  • Heat

Surface mining

A method of mining used for shallow deposits of ore

• large machines remove overburden of soil and rock

  • piles of overburden then get discarded into spoils

• forests are removed if present

• if there’s too much deforestation and spoils, water sources can become contaminated

• extracts 90% of nonfuel rock and mineral resources and 60% of coal

Subsurface mining

A method of mining used for deep deposits of ore

• Digs a deep vertical shaft into the ground and blasts subsurface tunnels/chambers to reach the deposit

• Special machinery needed to remove resources and bring to surface

• Disturbs less land than surface mining, produces less waste

  • More dangerous to human health

    • Cave-ins, explosions, fires, diseases (Black Lung Disease)

Spoils

Large piles of waste material in mining

Surface mining methods

Includes:

• Open-pit mining

• Strip mining

• Mountaintop removal

Depends on the resources being mined and local typography

Open-pit mining

A type of surface mining where giant machines dig holes in the earth and remove the coveted resource.

• Often is ores (iron, copper), sand, gravel, stone (marble, limestone)

Strip mining

A type of surface mining—there are 2 versions of this (area and countour) and it’s the most useful and economic solution to extracting minerals near the surface.

Area strip mining

A type of strip mining / surface mining used in relatively flat areas.

• An earthmover strips away overburden and power shovels remove the coveted resource

• The trench made is then filled in with overburden and a new cut is made parallel to the other one

• This process repeats until the whole site has a wavy series of highly erodible hills of rubble—”spoil banks”

  • These are easily eroded through chemical weathering especially

  • Regrowth of vegetation is slow since there’s no topsoil

Contour strip mining

A type of strip mining / surface mining used on hilly or mountainous areas.

• A power shovel cuts a series of terraces into the hillside

• An earthmover then removes the overburden and dumps it into the lower terrace

• A power shovel takes out the coveted resource/s

  • Creates an erodible highwall unless land is restored

  • Nearby water contamination is common

Highwall

A large wall of dirt left after contour strip mining that is created in front of a highly erodible soil/rock bank.

Can cause contamination of nearby water sources.

Mountaintop removal

A type of surface mining—explosives, power shovels, and dragline machines remove the tops of mountains to expose coal seams.

• Overburden gets dumped into streams and valleys below

• Toxic wastewater is produced from coal processing

  • Releases heavy metals like arsenic and mercury into surface water

• Increasing in the US and causing much environmental damage

Black Lung Disease

a hazard caused by subsurface mining and the inhalation of mining dust

Gangue

One of two components of ore after being extracted. This is the waste material.

Ore mineral

One of two components of ore after being extracted. This is the desired metal.

Tailings

Toxic waste piles produced from the removal of gangue from ore. These are where the toxic metals that leach into water supplies come from.

Smelting

Heat used to extract the desired metal from ore after gangue is removed.

• Roasts ores at extremely high temperature to release the desired metal

  • Without pollution control equipment, this causes lots of air pollution

Cyanide heap extraction

Chemicals used to extract the desired metal from ore after gangue is removed.

• Sprays crushed ores with a diluted solution of highly toxic cyanide salts in the open-air

  • Often used for gold

  • Solution can be recirculated by storing it in leach beds or overflow ponds

  • Very likely to get into nearby water supplies due to overflow or mismanagement

Biggest mining impact

scarring and disruption of the land surface since mining operations are expensive to clean up after

Land subsidence

An issue that comes from subsurface mining methods where the land starts to sink. Houses begin to tilt, sewer lines can crack, gas mains can break, and groundwater can be disrupted.

Pollution

Air and water _________ are both consequences of mining.

Acid mine drainage

Most mines have this issue with drainage of mine waste such as acid. Rainwater carries it to nearby streams or into groundwater.

Mining industry

This industry produces more toxic emissions than any other industry

Surface Mining Control and Reclamation Act

A mining law made in 1977 that requires mining companies to restore at least most of the surface-mined land by grading and replanting.

Old-growth forest

• a forest that developed over a long period of time without significant disturbance from humans

• typically around for several hundred years

• considered a climax community

• disappeared or reduced in size due to humans

Second-growth forest

• a forest that has regrown after major disturbances or harvesting (this disturbance is no longer evident)

• most forests are this

Tree plantation

• also called a tree farm

• an area of land with the specific use of harvesting trees

• usually done for wood, can be done for holidays, etc.

• trees usually in rows

Selective cutting

A tree harvesting method, considered the best.

• doesn’t cut every tree in the forest, only those of a certain age

• this allows the forest to continue to grow and be sustained

Clear cutting

A tree harvesting method, considered the most destructive.

• removes all trees from an area

Strip cutting

A tree harvesting method, pretty destructive

• strips of mature trees are cleared in rows from a forest

• removes entire stands of trees from a mature forest

Economically advantageous

An advantage of clear cutting.

Clear cutting is ________ ________ because the max yield of lumber is garnered in a short period of time, making it easy to sell.

Soil erosion

A disadvantage of clear cutting.

Clear cutting increases ____ ______ when all trees are cleared from land, making it hard for them to prevent weathering.

Increased sunlight

A disadvantage of clear cutting.

________ _______increases soil and stream temperatures.

Excessive flooding

A disadvantage of clear cutting.

With less trees to absorb water, ________ _______ is possible.

Slash and burn

The primary method for converting forests to farmland, especially rainforests.

• clear-cuts an area then burns all vegetation

• farmland is productive only for 3-5 years until it becomes so nutrient deprived that native plants can’t grow

• one of the most destructive ways to clear forests

Surface fire

Fires that are low in intensity and mostly burn surface litter and undergrowth

• easy to control

• canopy may be scorched but doesn’t spread or catch fire

Crown fire

The type of forest fire on the news—extremely intense fires that spread rapidly in the canopy since they have lots of oxygen to consume.

• most dangerous and hard to control, but preventable

Ground fire

The type of forest fire that occurs in the subsurface level, burning buried vegetation like humus.

• hard to contain but rarely seen naturally

Prescribed burns

Controlled forest fires. The underbrush is purposefully set on fire to stop them from fueling a fire that catches on the canopy.

Methods for preservation

• Reforestation

• Buying wood that was harvested using ecologically sustainable forestry techniques

• Reusing wood

• Prescribed burns

• IPM to protect forests from pests/pathogens