Envi Sci: Unit 5 Agriculture Flashcards
Urbanization
Removing of vegetation to convert natural landscape to city (urban)
Replaces soil, vegetation, wetlands , with impervious surfaces (concrete, asphalt, cement) which don’t allow water to infiltrate into the ground
Urbanization prevents groundwater recharge, causing precipitation to runoff into local bodies of water
Effects of urbanization on the environment
- Noise Pollution
- Urban Heat Islands
- Poor Air Quality
- Runoffs
- Saltwater Intrusion
Methods for mitigating (less severe) problems related to urban runoff
- Permeable Pavement
- Rain Garden
- Green Roofs
- Riparian Buffers- strips of trees that surround waterways
- Build wetlands and retention areas to capture runoff during storm events
- Rain barrels- catch rainfall and water can be used for watering plants, cleaning cars
- Sponge Cities
- Infiltration Trenches
- Tree Trench
- Building up, not Out
Reserves
Identified resources from which a usable nonrenewable mineral can be extracted profitably at current prices.
- Can increase if new deposits are found, prices increase, or new technology
Overburden
Soil & rock that overlies an ore and is displaced during mining but is not processed; may kept on site & used during reclamation
Ore
Rock which contains a metal or valuable mineral can be profitably extracted
Tailings
Tailings are leftover materials and waste rock after the process of SEPARATING the valuable fraction an ore.
Slag
Waste matter (usually liquid) separated from metals during the PROCESSING (smelting or refining) of ore.
Subsurface/ underground mining
Tunneling into mineral seams is very dangerous & expensive
- Workers experience health conditions from poor air quality (lung cancer), high health costs and insurance
- Dangerous- Tunnels can collapse; natural gas can explode; fires in mines may burn for years
- Water seeping into mine shafts dissolves forms acids and leech/dissolves heavy metals contaminates groundwater.
Benefit- does not disturb at much area on the surface
Surface mining- -
Strip Mining- removal of strips of overburden (vegetation, soil and rock) to reach underlying ores; often used for coal removal
Open Pit Mining- large pit extends vertically and horizontally; often used for metals
- Surface material called overburden is left in long ridges called spoil banks
~Spoil banks release contaminated runoff if not covered
- Creates huge holes in the earth which fill with contaminated groundwater.
Mountaintop Removal
- For Appalachian coal, mountain ridge tops are removed using explosives to access a coal bed.
- The material from the ridge top is crushed and dumped into adjacent river valleys, burying streams in toxic substances.
The Green Revolution
Most major improvements in farm production have come from technological advances and introduction of high yield varieties of wheat, rice and corn made
Started in the 1950’s with introduction of improved crop varieties to developing countries
Mechanization
- Replacement of human (& animal) workers with machines
- Particularly economical when fuel prices are low & labor prices are high
- Large up front costs and relies on fossil fuels
- Large farms are more profitable bc production costs fall as output increases
- Single crop farms (monoculture) are more efficient as each plant type needs specialized equipment
Genetically modified organisms (GMOs)
Fertilization
Irrigation
Pesticides
Are chemicals that kill biological pests to increase food yields.
- Herbicides kill plants
- Insecticides kill insects
- Fungicides kill fungi
Synthetically produced chemical pesticides: are the most common method of controlling pests in modern agricultural production may persist in the environment (and bioaccumulate) & kill non target species
- promote pesticide resistance
- may cause health effects in humans
Explain how tilling, slash and-burn farming, and the use of fertilizers cause environmental damage.
