International Commission on Irrigation & Drainage Commission Interationale des Irrigation et du Drainage

Multilingual Technical Dictionary (MTD)
<<    Browsing page 1 of 4    >>
Term No.Term Name/Term DescriptionAction
3847
U-abutment
Form of abutment where the wing walls return at 90o.
Similar Terms
4482
U-Pump
A reciprocating piston pump wherein the valves are placed in the piston and the flow through the cylinder is in one direction with no reversal......
Similar Terms
6717
Ubiquitous
Plant or animal species capable of thriving under many environmental conditions.
Similar Terms
658
UK Gallons
img:equations//631_658_e.jpg
Similar Terms
2638
Ultimate bearing capacity
The average load per unit of area required to produce failure by rupture of a supporting soil mass.
Similar Terms
1778
Ultimate pH
The pH after all diffusible anions and cations have been removed.
Similar Terms
5538
Ultra high-early strength cement
A cement that hardens more rapidly than ordinary Portland cement, because of its extraordinary particle fineness.
Similar Terms
6265
Ultrasonic velocity sensor, or Ultrasonic flowmeter
A microprocessor-based instrument that measures the velocity of flow at a certain depth by simultaneously transmitting ultrasonic pulses through the water from transceivers located on either side of a flowing stream. The difference between the times of travel of the pulses crossing the stream in an upstream direction and those travelling downstream.....
Similar Terms
9366
Ultraviolet (UV)-B Radiation
Solar radiation within a wavelength range of 280–320 nm, the greater part of which is absorbed by stratospheric ozone. Enhanced UV-B radiation suppresses the immune system and can have other adverse effects on living organisms......
Similar Terms
1822
Unavailable soil moisture, or Unavailable water
Soil moisture held so firmly by molecular forces that it cannot ordinarily be absorbed by plant roots with sufficient rapidity to produce growth......
Similar Terms
4901
Unavoidable farm losses
Principally those losses which are due to normal field evaporation and deep percolation.
Similar Terms
57
Unbiased error
An error that may be drawn at random from an error population with zero mean.
Similar Terms
197
Unbiasedness, or Unbiased estimate
An estimate is `unbiased` if the average of the sample estimates comes nearer and nearer to the true population parameter as the number of samples (all of the same size) is increased indefinitely......
Similar Terms
4176
Uncased well
A tubewell, such as in deep rock, with little or no casing.
Similar Terms
8578
Uncertainty
Outcomes resulting from each course of action that are not explicitly known and to which probabilities cannot be assigned......
Similar Terms
1145
Unconfined aquifer
An aquifer in which the groundwater table is free to rise and fall according to hydraulic gradients.
Similar Terms
5285
Unconfined water
Water that is free flowing.
Similar Terms
1142
Unconsolidated aquifer
An aquifer comprised mainly of gravels or other porous materials that may not be structurally stable when penetrated by a well bore......
Similar Terms
2659
Unconsolidated undrained test, or Quick test
A soil test when the time is not allowed for consolidation and the water content of the test specimen remains practically unchanged during the application of the confining pressure and the additional axial (or shearing) force......
Similar Terms
8951
Uncontrolled mosaic
A mosaic in which the photographs have not been adjusted by reference to ground control.
Similar Terms
2745
Uncontrolled spillway, or Ungated spillway
A spillway the crest of which permits water to discharge, whenever the reservoir surface is higher than the crest.
Similar Terms
5166
Under inlet
Any device other than a well that admits groundwater to a drain pipe. In its usual form it consists of an opening filled with broken stone or gravel......
Similar Terms
6677
Under story
A layer of foliage below the level of the main tree canopy.
Similar Terms
6439
Undercut-slope bank
The inside bank of a meandering stream that is eroded by stream action.
Similar Terms
7788
Underdrainage
Removal of excess water from the soil by a subsurface system of drainage.
Similar Terms
<<    Browsing page 1 of 4    >>