Water terms starting with A

312 terms

  1. AP analysis plan.
  2. APCD Air Pollution Control District.
  3. APE area of potential effect.
  4. API Method A statistical method to estimate the amount of surface runoff which will occur from a basin from a given rainstorm based on the antecedent precipitation…
  5. APO Arizona Projects Office.
  6. Appendix A small, fingerlike pouch that sticks out from the cecum (the first part of the large intestine near the end of the small intestine).
  7. Application efficiency The ratio of the average depth of irrigation water infiltrated and stored in the root zone to the average depth of irrigation water applied, expressed as…
  8. Applied water (delivered water) Water delivered to a user. Applied water may be used for either inside uses or outside watering. It does not include precipitation or distribution losses.
  9. Appraisal estimate An estimate used in an appraisal study as an aid in selecting the most economical plan by comparing alternative features or for determinimg whether more…
  10. Appraisal level of detail The level of detail necessary to facilitate making decisions on whether or not to proceed with a detailed study and evaluation of any alternative.
  11. Appraisal study (appraisal report) A study incorporating an appraisal level of detail.
  12. Approach channel The channel upstream from that portion of the spillway having a concrete lining or concrete structure.
  13. Appropriation The provision of funds, through an annual appropriations act or a permanent law, for federal agencies to make payments out of the Treasury for specified…
  14. Appropriative Water rights to or ownership of a water supply which is acquired for the beneficial use of water by following a specific legal procedure.
  15. Appurtenant Structures Auxiliary features of a dam such as outlet, spillway, powerhouse, tunnel, etc.
  16. Appurtentant structures Outlet works, spillways, bridges, drain systems, tunnels, towers, etc.
  17. Apron (fore apron) A section of concrete or riprap constructed upstream or downstream from a control structure to prevent undercutting of the structure.
  18. AQIA air quality impact analysis.
  19. AQMD Air Quality Management District.
  20. AQMP Air Quality Management Plan.
  21. Aquatic Having to do with water.
  22. Aquatic algae Microscopic plants that grow in sunlit water containing phosphates, nitrates, and other nutrients.
  23. Aquatic Protected Area A marine protected area consisting of freshwater resources.
  24. Aqueduct Man-made canal or pipeline used to transport water.
  25. Aqueous Having to do with water.
  26. Aquiclude A layer of clay which limits the movement of ground water.
  27. Aquifer A water-bearing geologic formation, sometimes confined between clay layers and sometimes on the surface.
  28. Aquifuge A geologic formation which has no interconnected openings and cannot hold or transmit water.
  29. Arable Suitable for farming. Having soil or topographic features suitable for cultivation.
  30. Arable land Land which when farmed in adequate size units for the prevailing climatic and economic setting, and provided with the essential on-farm improvements of…
  31. ARAR applicable or relevant and appropriate requirement.
  32. Arch Dam A concrete or masonry dam which is curved upstream in plan so as to transmit the major part of the water load to the abutments and to keep the dam in…
  33. Arch-buttress dam (or curved buttress dam) A buttress dam which is curved in plan.
  34. Arch-gravity dam An arch dam which is only slightly thinner than a gravity dam.
  35. Archaic In American archeology, a cultural stage following the earliest known human occupation in the New World (about 5,500 B.C. to A.D. 100).
  36. Archeology Study of human cultures through the recovery and analysis of their material relics.
  37. Archimedean screw An ancient water-raising device attributed to Archimedes, made up of a spiral tube coiled about a shaft or of a large screw in a cylinder, revolved by…
  38. Arching The transfer of stress from a yielding part of a soil or rock mass to adjoining less-yielding or restrained parts of the mass.
  39. Area Must have legally defined geographical boundaries, and may be of any size, except that the site must be a subset of the U.S.
  40. Area of Influence The area covered by the drawdown curves of a given pumping well or combination of wells at a particular time.
  41. Area of influence of a well Area surrounding a well within which the piezometric surface has been lowered when pumping has produced a maximum steady rate of flow.
  42. Area Wide Hydrologic Prediction System (AWHPS) A computer system which automatically ingests areal flash flood guidance values and WSR-88D products and displays this data and other hydrologic…
  43. Area-Capacity Curve A graph showing the relation between the surface area of the water in a reservoir, the corresponding volume, and elevation.
  44. Area-capacity table A table giving reservoir storage capacity, and sometimes surface areas, in terms of elevation increments.
  45. Arid A region that receives too little water to support agriculture without irrigation. Less than ten inches of rainfall a year is typically considered arid.
  46. Armoring. See riprap.
  47. ARMS Automated Records Management System.
  48. ARP address resolution protocol.
  49. Arroyo A Spanish word for brook that refers to a dry river, creek, or stream bed that temporarily or seasonally fills and flows after sufficient rain.
  50. Artesian Well Water held under pressure in porous rock or soil confined by impermeable geologic formations. An artesian well is free flowing. See confined aquifer.
  51. Artifact An object produced or shaped by human beings and of archaeological or historical interest.
  52. Artificial Control A weir or other man-made structure which serves as the control for a stream-gaging station.
  53. Artificial drains Man-made or constructed drains.
  54. Artificial recharge Addition of surface water to a ground water reservoir by human activity, such as putting surface water into spreading basins.
  55. ARTS Automated Resources Training System.
  56. ARWRI American River Water Resources Investigation.
  57. AS assistant secretary.
  58. ASAP as soon as possible.
  59. ASAPTRAN The software component of ASAP.
  60. ASC Administrative Service Center.
  61. ASCC Alaskan System Coordination Council (part of NERC).
  62. ASCE American Society of Civil Engineers.
  63. ASCII An acronym for American Standard Code that allocates a number to each key on the keyboard and that can be traded and read by most computer systems.
  64. ASCMP Administrative Support Career Management Program.
  65. ASCS Agricultural Stabilization and Conservation Service.
  66. ASOS The ASOS program is a joint effort of the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Department of Defense (DOD).
  67. ASR Alkali-silica reaction.
  68. ASSE American Society of Safety Engineers.
  69. Associated facility A term used by Reclamation to describe those facilities examined by the respective regional or area office.
  70. Association of Boards of Certification (ABC) An international organization representing over 150 boards which certify the operators of waterworks and waste water facilities.
  71. ASSR alkali-silicate/silica reaction.
  72. ASTM Abbreviation for the American Society for Testing and Materials, which is responsible for the issue of many standard methods used in the energy industry.
  73. ASTS above ground storage tanks.
  74. Asymmetric Not similar in size, shape, form or arrangement of parts on opposite sides of a line, point or plane.
  75. At-rest earth pressure The value of the earth pressure when the soil mass is in its natural state without having been permitted to yield or without having been compressed.
  76. ATF Austin Field Office (Austin, TX).
  77. Atmospheric Pressure The pressure of the air at sea level; one standard atmosphere at zero degrees centigrade is equal to 14.695 pounds per square inch (1.
  78. Attenuation A mechanism for controlling gene expression in prokaryotes that involves premature termination of transcription.
  79. Atterberg limits (consistency limits) The boundaries (determined by laboratory tests) of moisture content in a soil between the liquid state and plastic state (known as liquid limit), between…
  80. Attribute survey Survey to determine the important components of the recreational experience.
  81. ATV all-terrain vehicle.
  82. Atypical (a-tip'ih-kul) irregular; not conformable to the type; an unusual type.
  83. Auger A rotating, screw-type device that moves material through a cylinder. In alcohol production, it is used to transfer grains from storage to the grinding…
  84. AUM animal unit months.
  85. AUO administratively uncontrollable overtime.
  86. Author's signature This is the signature of the person or persons with primary responsibility for writing the document.
  87. Authorization The issuance of approval, by a credit card issuer, merchant, or other affiliate, to complete a credit card transaction.
  88. Authorized Reclamation project A congressionally approved Bureau of Reclamation project that has been authorized for specific purposes.
  89. Automated Event Reporting Gage (see Tipping Bucket Rain Gage); for river stage gages, IFLOWS pressure transducer type gages can be programmed to report if water surface rises or falls…
  90. Automated Local Evaluation in Real Time (ALERT) A local flood warning system where river and rainfall data are collected via radio signals in real-time at an ALERT base station.
  91. Automated Tone Dial Telephone Data Collection System (ATDTDCS) Data collection system where cooperative observers collect precipitation, stage, and temperature data then transmit the data to the NWS ATDTDCS computer…
  92. Automatic generation control (AGC) Computerized power system regulation to maintain scheduled generation within a prescribed area in response to changes in transmission system operational…
  93. Auxiliary equipment Accessory equipment necessary for the operation of a generating station.
  94. Auxiliary Spillway A spillway, usually located in a saddle or depression in the reservoir rim which leads to a natural or excavated waterway, located away from the dam which…
  95. AVADS Automated Vacancy Announcement Distribution System.
  96. Available capacity The amount of water held in the soil that is available to the plants. See water holding capacity.
  97. Average A stock market average is a mathematical way of reporting the composite change in prices of the stocks that the average includes.
  98. Average annual runoff For a specified area, the average value of annual runoff amounts calculated for a selected period of record that represents average hydrologic conditions.
  99. Average degree of consolidation The ratio of the total volume change in a soil mass at a given time to the total volume change anticipated in the soil mass due to primary consolidation.
  100. Average energy The total power generation produced by a powerplant during all of the years of its actual or simulated operation divided by the number of years of actual…