Water terms starting with A

312 terms

A Abbreviation for adenine.
A&E (A/E) architectural and engineering.
AAC All American Canal.
AAHU average annual habitat units.
AAM annual arithmetic mean.
AAR alkali-aggregate reaction.
AB Abbreviation for antibody.
ABC activity based cost accounting - an accrual-based accounting method for determining unit-based costs of delivering services by allocating the costs to…
Aberrant Atypical, departing from the normal type or structure.
Abiotic Absence of living organisms.
Ablation (a-BLAY-shun) In medicine, the removal or destruction of a body part or tissue or its function.
Abrasion Wearing away of surfaces by friction.
Absolute pressure Atmospheric pressure plus gauge pressure.
Absorbed dose Energy imparted to a body by radiation, measured per unit mass (kg) of tissue.
Absorbed water Water held mechanically in a soil or rock mass and having physical properties not substantially different from ordinary water at the same temperature and…
Absorption (ub-SORP-shun) The process of taking nutrients from the digestive system into the blood so they can be used in the body.
Absorption factor The fraction of a chemical making contact with an organism that is absorbed by the organism.
Abutment That part of the valley wall against which the dam is constructed. The part of a dam that contacts the riverbank.
Abutment Seepage Reservoir water that moves through seams or pores in the natural abutment material and exits as seepage.
AC Armor Class or Defense.
ac-ft acre-foot, acre-feet.
Acceleration The right of the lender to demand payment on the outstanding balance of a loan.
Accelerogram The record from an accelerometer showing acceleration as a function of time.
Acceptable daily intake (ADI) Estimate of the largest amount of a chemical to which a person can be exposed on a daily basis that is not anticipated to result in adverse effects…
access charge A charge levied on a power supplied, or its customer, for access to a utility's transmission or distribution system.
Access control point A location staffed to restrict entry of unauthorized personnel into a risk area during emergency and/or disaster events.
Access shaft Concrete portion of an outlet works between the shaft house and the gate chamber. The access shaft provides vertical access to the gates.
Accident assessment The evaluation of the nature, severity, and impact of an accident. Dam operating personnel are primarily responsible for accident assessment for incidents…
Acclimation Adjustment of an organism to a new habitat or environment.
Accretion Process of growth whereby material is added to the outside of nonliving matter.
Accuracy Department of Defense parlance for the notion that information has been maintained and transferred in such a way as to be inviolate (the information has…
ACEC area of critical environmental concern.
ACER Assistant Commissioner - Engineering and Research.
ACES Automated Coastal Engineering System.
ACGIH American Conference of Government Industrial Hygienists.
ACHP Advisory Council on Historic Preservation.
ACID A solution that has an excess of hydrogen ions (H+).
Acid Rain A term used to describe precipitation that has become acidic (low pH) due to the emission of sulfur oxides from fossil fuel burning power plants.
Acidic The condition of water or soil which contains a sufficient amount of acid substances to lower the pH below 7.0.
Acidified The addition of an acid (usually nitric or sulfuric) to a sample to lower the pH below 2.0.
ACR alkali-carbonate reaction.
Acre (ac) Unit for measuring land, equal to 43,560 sq. ft., 4840 sq. yds., or 160 sq. rds.
Acre-foot (ac-ft) A term used in measuring the volume or amount of water needed to cover 1 acre (43,560 square feet) 1 foot deep (325,851 gallons or 1,233.5 cubic meters).
ACRM Assistant Commissioner-Resources Management.
Activated carbon See activated charcoal.
Active (Usable) Storage Capacity The total amount of reservoir capacity normally available for release from a reservoir below the maximum storage level.
Active capacity The reservoir capacity normally usable for storage and regulation of reservoir inflows to meet established reservoir operating requirements.
Active conservation capacity (active storage) The reservoir capacity assigned to regulate reservoir inflow for irrigation, power, municipal and industrial use, fish and wildlife, navigation…
Active Conservation Storage The portion of water stored in a reservoir that can be released for all useful purposes such as municipal water supply, power, irrigation, recreation…
Active earth pressure The minimum value of earth pressure. This condition exists when a soil mass is permitted to yield sufficiently to cause its internal shearing resistance…
Active fault A fault which, because of its present tectonic setting, can undergo movement from time to time in the immediate geologic future.
Active transport The movement of a molecule or groups of molecules across a cell membrane, which requires the expenditure of cellular energy, because the direction of…
activity The number of transformations that take place each second in a given amount of radioactive material.
ACTS Action Correspondence Tracking System.
Acute (uh-KYOOT) Symptoms or signs that begin and worsen quickly; not chronic.
Acute exposure A single exposure to a toxic substance which results in severe biological harm or death.
Acute toxicity The ability of a substance to cause poisonous effects resulting in severe biological harm or death soon after a single exposure or dose.
ACWA Association of California Water Agencies.
Adaptation Adjustment of a population to changes in environment over generations, associated (at least in part) with genetic changes resulting from selection imposed…
Additive effect Combined effect of two or more chemicals equal to the sum of their individual effects.
Adhesion The "stick" between two touching objects. Adhesion implies a static condition, while traction implies a moving condition.
ADI acceptable daily intake.
Adirondack Type Snow Sampling Set A snow sampler consisting of a 5-foot fiberglass tube, 3 inches in diameter, with a serrated-edge steel cutter at one end and a twisting handle at the…
Adit A nearly horizontal underground excavation in an abutment having an opening in only one end.
ADMS Accessibility Data Management System.
ADP Abbreviation for adenosine diphosphate.
ADR alternative dispute resolution.
Adsorbate The material being removed by the adsorption process.
Adsorbed water Water in a soil or rock mass, held by physico-chemical forces, having physical properties substantially different from absorbed water or chemically…
Adsorbent The material (for example activated carbon) that is responsible for removing the undesirable substance in the adsorption process.
Adsorption The adhesion, in an extremely thin layer, of molecules (as in gases, solutions, or liquids) to the surface of solid bodies or liquids with which they are…
ADSS Advanced Decision Support System.
ADT average daily traffic.
Advanced Decision Support System (ADSS) Computer software designed to provide easy access to and allow efficient use of methods of analysis and information management.
Advanced Weather Interactive Processing System (AWIPS) A system that will eventually replace Automation of Field Operations and Services, AFOS.
ADVIS A program which combines the Antecedent Precipitation Index (API) method of estimating runoff with unit hydrograph theory to estimate streamflow for a…
Advisory Council on Historic Preservation (ACHP) Executive agency responsible for ensuring requirements of National Historic Preservation Act and 36 CFR Part 800 are met.
AEB Elephant Butte Power and Storage Division (Truth or Consequences, NM).
Aeolian (eolian) Materials carried, deposited, produced, or eroded by the wind.
Aeolian deposits Wind-deposited material such as dune sands and loess deposits.
Aerate To impregnate with gas, usually air.
Aeration The process of adding air to water by either passing air through water or passing water through air.
Aeration Zone A portion of the lithosphere in which the functional interstices of permeable rock or earth are not filled with water under hydrostatic pressure.
Aerial cover Ground area circumscribed by the perimeter of the branches and leaves of a given plant or group of plants (generally used as a measure of relative…
Aerobic In biochemistry, reactions that need oxygen to happen or happen when oxygen is present.
AF acre-feet.
Affected Environment For an environmental impact statement, a description of the existing environment covering information necessary to assess or understand the impacts.
AFO Auburn-Folsom Office (Auburn, CA).
AFRP Anadromous Fish Restoration Program.
Afterbay The tail race of a hydroelectric power plant at the outlet of the turbines. The term may be applied to a short stretch of stream or conduit, or to a pond…
Afterbay (tailrace) The body of water immediately downstream from a powerplant or pumping plant. A reservoir or pool that regulates fluctuating discharges from a…
Afterbay dam (reregulating dam) A dam located downstream from a large hydroelectric powerplant used to regulate discharges downstream. See regulating dam.
afy (af/yr) acre-feet per year.
Ag Abbreviation for antigen.
AGC automatic generation control.
Age tank (day tank) A tank used to store a chemical solution of known concentration for feed to a chemical feeder.
Agglomerate An ice cover of floe formed by the freezing together of various forms of ice.
Aggradation Geologic process wherein streambeds, floodplains, sandbars, and the bottom of water bodies are raised in elevation by the deposition of sediment; the…
Aggregate 1. A clump or mass formed by gathering or collecting units. 2. A body of loosely associated cells, such as a friable callus or cell suspension. 3.
AGM annual geometric mean.