Water and Air Exam Review

Water Sources

  • Saltwater vs Freshwater

    • Saltwater: 3.1% - 3.8% salinity (oceans)

    • Freshwater: 0% salinity

    • Ecosystems:

    • Oceanography: study of saltwater ecosystems

    • Limnology: study of freshwater ecosystems

  • Water Statistics:

    • 70% of Earth's surface covered with water

    • 98% is saltwater; 2% is freshwater

    • 87% of freshwater is ice

    • 12% is groundwater

    • 1% is surface water

The Hydrologic Cycle

  • Describes water movement in various forms:

    • Key Processes:

    • Evaporation

    • Transpiration

    • Condensation

    • Precipitation

    • Water Movement: above/below ground (surface runoff, groundwater)

Evapotranspiration

  • Evaporation:

    • Conversion of liquid water to gas (e.g., boiling water)

  • Transpiration:

    • Water absorption by plants from soil, released into atmosphere

  • Combined process referred to as Evapotranspiration

Condensation & Precipitation

  • Condensation: gas to liquid (cloud formation)

  • Precipitation: atmospheric water falling to Earth (rain, snow)

The Amazon Rainforest

  • Role in Hydrological Cycle:

    • Transpiration from trees influences local and regional moisture

    • Houses approx. 390 billion trees that release significant moisture into the atmosphere

    • Critical for agriculture and water reserves in South America

Deforestation's Impact

  • Disrupts water cycle by decreasing transpiration, leading to droughts

  • Requires maintaining 80% of the forest for hydrological health

Surface and Groundwater

  • Surface Runoff:

    • Water moving downhill due to gravity; replenishes rivers/lakes

  • Groundwater: water stored in soil, sand, rocks (aquifers)

  • Gravity and percolation govern underground water movement

Types of Surface Freshwater

  • Rivers/Streams: flowing bodies (streams are smaller rivers)

  • Lakes/Ponds: standing bodies of inland water

  • Wetlands: areas covered by standing water part of the year

Watersheds & Water Basins

  • Watershed: area draining into a specific water body

  • Basin: larger watershed incorporating multiple watersheds

Water Rights & Management

  • Tragedy of the commons and disputes over water rights (e.g., Tri-state water war)

Clean Water Legislation

  • Clean Water Act (1972): regulates pollutant discharges into US waters

  • Safe Drinking Water Act (1974): ensures water quality for drinking

  • Oil Pollution Act (1990): response mechanisms for oil spills

Water Pollution Types

  • Point Source Pollution: identifiable sources, e.g., pipes

  • Non-point Source Pollution: diffuse sources, e.g., agricultural runoff

Eutrophication

  • Nutrient-rich runoff leads to excessive algae growth, oxygen depletion, and aquatic die-offs

  • Driven by human activities, such as fertilizer use

Ground Level Ozone & Air Quality

  • Ground-level ozone forms from pollution and sunlight, causing health issues

  • Various pollutants regulated by the Clean Air Act to ensure air quality

Summary

  • Understanding water sources, the hydrological cycle, and legislation is crucial for sustainable water and environmental management.