Environmental Science: Water Resources, Pollution, and Air Quality

The Water Cycle

1. Evaporation

2. Transpiration

3 Condensation

4. Precipitation

Watershed

Land area that drains water into a specific body of water.

Water basin

A larger watershed that collects water from a broad region.

Percolation

Water moving downward through permeable ground due to gravity.

Water table

Boundary between the zone of aeration and the zone of saturation.

Aquifer

Saturated underground material that stores groundwater; it is not an underground lake

Ogallala Aquifer

A major North American aquifer used for irrigation. Your slides estimate depletion at about 2 feet per year on average, compared with recharge of about 1 inch per year.

Drawdown

A drop or change in groundwater level caused by pumping.

Cone of depression

The cone-shaped lowering of the water table around a pumping well.

Erosion

Movement of soil or sediment by water, wind, ice, or gravity.

Sedimentation

Deposition of sediment in a body of water.

Amazon rainforest (Case Study)

Trees transpire water into the atmosphere, helping form clouds and supply rainfall. Deforestation reduces transpiration and can contribute to drought, savannafication

Continental Divide

According to your slides, water west of the divide flows toward the Pacific Ocean, while water east flows toward the Atlantic Ocean

Photosynthesis (Makes Oxygen)

Plants use sunlight, water, and carbon dioxide (CO₂) to make glucose (sugar) and oxygen (O₂). This process releases oxygen into the water or air.

Cellular respiration (Uses Oxygen)

Organisms break down glucose using oxygen to release energy, producing carbon dioxide and water. This process uses up dissolved oxygen (DO) in water.

Dissolved oxygen (DO)

is oxygen dissolved in water. Many aquatic animals, including fish, depend on it. If oxygen levels fall below what they need, they can suffocate.

Eutrophication

Eutrophication is a process caused by excess nutrients entering a body of water and potentially resulting in massive fish die-offs.

Hypoxic

Lacking sufficient oxygen

Anoxic

Having no oxygen

Algae bloom

Rapid, excessive algae growth

CAFO

Concentrated Animal Feeding Operation, where large numbers of animals are confined and raised in a relatively small area.

Runoff

Water flowing over land, potentially carrying fertilizer or waste into water bodies.

Leaching

Water moving through the ground and carrying dissolved substances into groundwater.

Turbidity

Cloudiness or muddiness of water caused by suspended material.

Dead zone

An ocean region with very low dissolved oxygen. Your slides connect the Gulf of Mexico dead zone near Louisiana to fertilizer runoff from the Mississippi River Basin.

Freshwater algae blooms

Often green and associated in the slides with cyanobacteria.

Red tides

Saltwater algae blooms associated in the slides with red-colored dinoflagellates.

Oil spills

Oil is less dense than water, so it tends to float on the surface. An oil slick can block sunlight, reduce photosynthesis, disrupt dissolved oxygen levels and aquatic food webs, and coat wildlife so that animals struggle to fly or swim.

Deepwater Horizon

The Oil Pollution Act (OPA) of 1990 strengthened the ability to prevent and respond to oil spills and created an oil-tax-funded trust fund for cleanup when the responsible party cannot or will not pay.

Microplastics

Tiny plastic particles formed as plastic products break down. Synthetic fabrics such as polyester and fleece can release plastic fibers.

Bioaccumulation up the food chain

In your lecture, organisms consume plastic and it moves through food-chain relationships as predators eat prey.

Great Pacific Garbage Patch

Not one solid floating island; it consists of discarded fishing nets, larger plastic items, and microplastics spread across an area

Extended Producer Responsibility (EPR)

The idea that companies should be responsible for a product's environmental impacts throughout its life cycle, from "cradle to grave."

Safe Drinking Water Act (SDWA) of 1974

Signed by President Ford. It establishes minimum drinking-water quality standards, requires public water systems to comply, and is overseen by the EPA, with monitoring responsibilities delegated in part to states.

The Tri-State Water War

1. Georgia, Drinking water for the growing Atlanta metro area, supplied in part by Lake Lanier.

2. Alabama Industrial water use and water for cooling a nuclear reactor.

3. Florida Freshwater flowing into Apalachicola Bay to support its oyster industry.

Oyster Case study Effects

Less freshwater flowing into Apalachicola Bay → higher salinity (saltier water) → increased stress on oysters and greater reproductive success for oyster predators → more pressure on the oyster population.

Tragedy of the commons

A conflict that can occur when people or groups share a resource but compete over how much each can use.

Estuary

A coastal area where freshwater from a river meets saltwater from the ocean.

Salinity

The concentration of dissolved salts in water.

Predation

One organism hunting and consuming another

Resilience

The ability to adapt to and recover from stress.

UV-A

Penetrates deeper into the skin, contributes to premature skin aging, and is associated with melanoma

UV-B

Damages the outer skin layers, causes sunburn, and is associated with basal cell and squamous cell carcinomas.

UV-C

Blocked by the ozone layer; the slides also describe its use for sterilization by disrupting the DNA of microorganisms.

Sequence of CFC'S

1. CFCs drift into the stratosphere.

2. UV radiation releases chlorine from the CFCs.

3. Chlorine reacts with and breaks down ozone molecules.

4. Less ozone means less protection from harmful UV radiation.

Montreal Protocol of 1989

established an international agreement to phase out CFCs. Your slides emphasize it as a successful example of international environmental cooperation.

Clean Air Act Amendments, 1990

Addressed CFCs, leaded gasoline, vehicle emissions, and acid rain.

Cap-and-trade

The EPA sets an overall emissions cap. Companies that reduce emissions below their allowances can sell credits to companies that need them. The overall cap is reduced over time.