ON ANY LETTER ABOVE AND CHALLENGE YOURSELF!
Reducing the degree or intensity of, or eliminating, pollution, as
a water pollution abatement program.
Abiota Those non-living factors which are present in and affect the characteristics of a given ecosystem.
Acre-Foot (AF)vA unit commonly used for measuring the volume of water; equal to the quantity of water required to cover one acre (43,560 square feet or 4,047 square meters) to a depth of 1 foot (0.30 meter) and equal to 43,560 cubic feet (1,234 cubic meters), or 325,851 gallons.
Adaptive Management A process for implementing policy decisions as an ongoing activity that requires monitoring and adjustment. Adaptive management applies scientific principles and methods to improve resource management incrementally as managers learn from experience and as new scientific findings and social changes demand.
Adenosine Triphosphate (ATP) An organic, phosphate-rich compound important in the transfer of energy in organisms. Its central role in living cells makes it an excellent indicator of the presence of living material in water. A measure of ATP therefore provides a sensitive and rapid estimate of Biomass. ATP is reported in micrograms per liter of the original water sample.
Adfluvial Migrating between lakes and rivers or streams; typically used of fish species.
Advection The process by which solutes are transported by the bulk of flowing fluid such as the flowing ground water.
Affluent (Stream) A stream or river that flows into a larger one; a Tributary.
Agglomeration (Water Quality) The grouping of small suspended particles into larger particles that are more easily removed through filtration, skimming, or settling. Also see Coagulation.
The raising of a stream-channel bed with time due to the Deposition
of sediment that was eroded and transported from the upstream watershed
or the channel.
Aggrading The building up of a stream channel which is flowing too slowly to carry its sediment load.
Alachlor A herbicide, marketed under the trade name Lasso, listed by the U.S. Environmental Protection Agency (EPA) as a probable human carcinogen and found frequently in streams and rivers, particularly following floods and periods of heavy rain. Alachlor is used extensively for weed control in corn, cotton, and soybean fields.
Alevin Larval salmonid hatchling with yolk sac still attached. Alevin reside in the redd (nest) until the yolk sac is absorbed and they emerge from the gravel.
Algal Blooms Rapid growth of algae on the surface of lakes, streams, or ponds; stimulated by nutrient enrichment. A heavy growth of algae in and on a body of water as a result of high phosphate concentration such as from farm fertilizers and detergents. It is associated with Eutrophication and results in a deterioration in water quality.
Allochthonous Material Organic material that falls into a stream from the surrounding land. Compare to Autochthonous Material.
Allogenic Exogenous, caused by external factors, such as a change in a habitat or environment caused by flooding. Contrast with Autogenic.
Allogenic Succession Predictable changes in plant and animal communities in which changes are caused by events external to the community, for example, fire, drought, floods, etc.
Alluvial Fan Flooding Flooding occurring on the surface of an Alluvial Fan or similar landform which originates at the apex and is characterized by high-velocity flows, active processes of erosion, sediment transport, deposition, and unpredictable flow paths.
Amalgamation The dissolving or blending of a metal (commonly gold and silver) in mercury to separate it from its parent material.
Anadromous Ascending rivers from the sea, at certain seasons, for breeding. For example, salmon and shad are anadromous fish.
Anastomosing The branching and rejoining of channels to form a netlike pattern.
Anthropogenic Involving the impact of man on nature; induced, caused, or altered by the presence and activities of man, as in water and air pollution.
Aquatic guidelines Specific levels of water quality which, if reached, may adversely affect aquatic life. These are nonenforceable guidelines issued by a governmental agency or other institution.
Aquatic-life criteria Water-quality guidelines for protection of aquatic life. Often refers to U.S. Environmental Protection Agency water-quality criteria for protection of aquatic organisms. See also Water-quality guidelines and Water-quality standards.
Aquifer A water-bearing layer of soil, sand, gravel, or rock that will yield usable quantities of water to a well.
Area of Critical Environmental Concern (ACEC) An area on Public Lands where special management attention is required to protect and prevent irreparable damage to historic, cultural, or scenic values, fish and wildlife resources, or other natural systems or processes, or to protect people from natural hazards.
Assessment Report A comprehensive record of historical, existing and projected water quality conditions of a particular watershed.
Assimilation The ability of a body of water to purify itself of pollutants.
Assimilative Capacity The ability of air, a natural body of water, or soil to effectively degrade and/or disperse chemical substances. If the rate of introduction of pollutants into the environment exceeds its assimilative capacity for these substances, then adverse effects may result to habitat and wildlife.
P.O. Box 606, Manton, CA 96059
2017 - All Rights Reserved