• Atmosphere
  • Precipitation
    • Precipitation affects the amount of water in a reservoir, as well as influences it's chemical composition through processes like runoff. Areas with higher precipitation-caused erosion may have murkier water, while harder-surfaced areas may have clearer water.
• Hydrosphere
  • Alkalinity
    • Alkalinity is strongly influenced by the surrounding geology. For example, areas with large limestone deposits tend to have higher alkalinity values. These deposits can affect the quality of the water as it flows through them. Additionally, alkalinity acts as a buffer to the input of acids into water bodies, so highly alkaline waters tend to have more stable pH levels.
  • Dissolved Oxygen

    • As water mixes with air, atmospheric oxygen (O₂) dissolves into the water. This dissolved oxygen then becomes available for fish and other aquatic animals to utilize. Oxygen can also be added to the water via photosynthesis from aquatic plants. However, when these plants die, bacteria digesting the dead matter remove the oxygen from the water, at times faster than the oxygen production rates from living plants and turbulent mixing. This can produce "dead zones" where there isn't enough dissolved oxygen for fish and other organisms to survive.

  • Salinity
    • Even though precipitation falls as fresh water, it acquires salinity as it flows through soil and rock by dissolving the salt compounds found within them. This runoff affects the ocean's average salinity, which is around 35 parts per thousand. Estuaries are the regions of intermediate salinity where fresh water in rivers mixes with ocean water.
  • Water Temperature
    • The temperature of a water body depends on many factors including whether it is shaded or exposed to direct sunlight, depth of water, inputs of melt water from snow or glaciers, heat from geothermal processes, and human uses of the water such as for cooling power plants. Heat exchange occurs between the atmosphere and the water body’s surface. Solar energy warms the water while latent heat released by evaporation cools water.
  • Water pH
    • The chemicals dissolved in water can affect its pH, which in turn, determines what can live there. Fresh water—equilibrated with the atmosphere and the carbon dioxide in the air—has a pH of about 5.5.
  • Water Transparency
    • The water's clarity determines how much photosynthesis can occur below the surface, influences the amount and types of photosynthetic organisms that can live there. A water body's turbidity also causes particles to be suspended within the water column. Greater turbulence allows larger and more particles to be suspended, while less turbulence allow these large particles—like sand—to settle much faster than smaller particles like clays.
  • Nitrates

    • Although aquatic plants need nutrients to grow and reproduce, an excess of these nutrients can cause significant overgrowths and blooms, particularly with microscopic plants called phytoplankton. Excess nitrogen and phosphorus compounds are commonly found in water bodies around the world due to human activities like agriculture and waste water runoff.

• Pedosphere
  • Soil pH
    • As water flows through soil, it dissolves chemicals that can change the pH or alkalinity of the water body in which it flows into. Altering these characteristics has substantial impacts of the wildlife in that water body.

Water is a crucial resource for life and a key player in many important chemical reactions. These reactions help shape the land and change the composition of water bodies, which in turn, affect the wildlife that live in those bodies. For example, precipitation can capture aerosols in the atmosphere, acidifying the rain or snow, which slowly degrades rocks and minerals over time. These dissolved impurities trickle into nearby bodies of water, altering it's chemical composition and capability of supporting different types of life.

Before taking measurements of the water quality in your local community, it's beneficial to first focus your approach by creating research questions. A few examples of these questions include:

• What is the water quality in my environment?
• Is my water safe to drink?
• Is my water safe to swim or bathe in?
• Is my water safe to water crops and plants?
• What impacts does water—both above and below ground—have on our environment?
• If we have a large rain event, will the area around the water body flood?
• Can we grow crops in our soil now?
• Is my area prone to erosion and landslides?
• How does water quality impact living organisms?
• What types of macroinvertebrates live in the water body?
• How does human activity affect water quality?

Data reported from measurements included in this bundle can have many uses locally, for downstream communities, and throughout your watershed.

Acknowledgements

Compilers:

• Claudia Caro
• Olawale Oluwafemi (Femi)

Editors:

• Dr. Dixon Butler
• Prof. Cartalis