| Term No. | Term Name | Term Description |
| 1624 | A horizon | A mineral horizon formed or forming at or adjacent to the surface that shows: a) an accumulation of organic matter intimately associated with the mine..... |
| 6131 | A-Frame | An open structure tapering from a wide base to a load-bearing top...... |
| 8096 | A/D Converter | Device used to covert an analog input signal to a digital output form that can be understood by a computer. ..... |
| 7162 | Abatement | A reduction in the degree or intensity of pollution...... |
| 6608 | Abiocoen | All the non-living components of the environment. ..... |
| 6849 | Abioseston | The non‑living components of the seston...... |
| 6609 | Abiotic | Referring to the non-living components of the environment. ..... |
| 6804 | Abiotic productivity | The amount of material yielded by an inorganic, renewable resource process...... |
| 751 | Ablation | The combined processes (such as sublimation, melting,or calving) which remove snow or ice from the surface of a glacier or snowfield. ..... |
| 1374 | Abnormal scour | Scour caused by deflected on-flowing currents, as by the river running tangentially forming an eddy when leaving the curve of the protection structure..... |
| 1409 | Abrasion | 1 - Mutual rubbing of particles of sediment in flowing water as well as in the channel bed as a result of which these particles tend to decrease in si..... |
| 6427 | Abrasion | 1 - A wearing away process, as of ice or snow by melting, or of land by the action of running surface water. 2 - See 1409...... |
| 5959 | Abrasion drill, or Rotary drill | A type of drill that grinds rock into small particles through the abrasive effect of a bit that rotates in the hole...... |
| 2571 | Abridged trial load method, or Simplified trial load method | Used for arch dam preliminary design work by using tables and curves for determining deflections of arches. Modified assumptions are made with regard ..... |
| 4260 | Absolute artesian well | An artesian well which is isolated by sealing from a permeable layer, if it happens to traverse it, overlying the upper confining bed of the artesian ..... |
| 3041 | Absolute paths | Paths relative to a base such as earth...... |
| 1122 | Absorbed water | Water held on the surface of individual soil particles by the force of molecular attraction with emission of heat (heat of wetting)...... |
| 4146 | Absorbing well, Drain well, Dead well, or Negative well | 1 - A shaft or well driven through an impermeable stratum to allow surface water to drain through to a permeable one. 2 - See 2559 (drain well)...... |
| 1939 | Absorption | The upward passage, by osmosis, of inorganic salts in solution from soil water to the root hairs...... |
| 3999 | Absorption | An act or process of absorbing water by sub-soil in the perimeter of the canals/streams.(See 1939)...... |
| 1961 | Absorption coefficient | Represents the volume of gas, reduced to standard conditions (0oC and 760 mm pressure), dissolved in one volume of liquid when the pressure of the gas..... |
| 870 | Absorption loss | Seepage into the bed of a canal that occurs shortly after water is turned into the dry canal (as the canal is being primed). (See 4000). ..... |
| 4000 | Absorption losses | Losses of water from a canal or reservoir by capillary action and percolation, and, in the case of a canal, during the process of priming.(See 870)...... |
| 5940 | Absorptive form liners | Canvas and other cotton, blotter type paper and muslin covered chip boards, used as lining materials for forms to remove air bubbles and excess water ..... |
| 6546 | Absorptive outlet | Outlet channel in which contour furrows, ridges, ditches, or other such means are used to collect and hold runoff until it is absorbed by the soil...... |
