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

Multilingual Technical Dictionary (MTD)
<<    Browsing page 1 of 2    >>
Term No.Term Name/Term DescriptionAction
1560
Fish-scale sao
When used as bank revetment, one `sao` is overlapped by another at the upstream like fish saddles and the whole work is called a `fish-scale sao` (illustrated)......
Similar Terms
2240
Fishway, or Fish-pass
A structure facilitating the migration of fish around a dam, weir or other obstructions in streams (illustrated).
Similar Terms
2241
Fish screen
A device intended to prevent the entrance of fish into a conduit.
Similar Terms
2966
Fish belly flap
A hollow flap (gate leaf) having its lower plating stimulating the belly of a fish. This form has an excellent resistance to torsion stress (illustrated)......
Similar Terms
2967
Fish belly flap gate
A sill control device using fish belly flap as its damming structure (illustrated).
Similar Terms
3877
Fish ladder
A fishway consisting of a series of basins between which fish may make their way by passing through holes in the walls intervening between the basins or by jumping over the walls......
Similar Terms
3878
Fish protection works
Structures or devices to permit safe upstream or downstream passage of migratory fish; to keep the fish away from entering waterways where they may be injured, killed or carried through canal systems to the irrigated field; and to transfer them in nearby basins, if considered desirable......
Similar Terms
3879
Hydraulic fish pass
A conduit of a special shape with doors or gates, at either end, which can be controlled firstly to lure fish into a chamber and subsequently to either fill the chamber admitting fish to the headwater or empty the chamber and release fish into the tailwater (See 3906)......
Similar Terms
3880
Diagonal baulk fish pass
A type of fish pass applicable to weirs of relatively low height and easy gradient, consisting of a ridge, or baulk of timber or concrete, fixed diagonally (inclination angle, generally, between 25o to 45o) along the downstream slope of the weir at a gradient always easier than that of the latter. The function of the diagonal is to provide a channe.....
Similar Terms
3882
Dished channel fish pass
A type of fish pass suited only to low weirs (not exceeding 1.5 metres in height) of easy gradient (not steeper than 1 in 4) situated in a narrow river consisting of a depression or cut in the crest of the weir connected downstream by a converging channel through which the fish pass (illustrated)......
Similar Terms
3883
Denil fishway, or Channel type fishway
A type of fishway consisting of a straight channel with closely spaced baffles set at an angle to the axis of the channel. The baffles with parts of the channel walls and bottom form secondary channels, while they leave free a relatively large proportion of the channel for the straight main flow through which the fish pass......
Similar Terms
3884
Pool and jet fishway, or Pool and transverse fish pass
A fish ladder that consists of a series of pools in a stepped arrangement from tailwater to headwater. The flow from pool to pool may be over solid obstacles, or through notches or orifices in the obstacles, or a combination of these two......
Similar Terms
3885
Pool and overfall fishway
A type of pool and jet fishway in which the flow passes over the whole width of the solid obstacles.
Similar Terms
3886
Pool and notch fishway, Notch fish ladder, or Notched overfall fishway
A type of pool and jet fishway in which the flow passes through notches cut in the obstacles and not over the whole of the obstacles......
Similar Terms
3887
Pool and orifice fishway, Orifice fish ladder, or Submerged jet fish ladder
A type of pool and jet fishway in which the flow passes through orifices provided in the obstacles (baffle) near the bottom......
Similar Terms
3888
Cail type fishway
A type of pool and orifice fishway with staggered orifices.
Similar Terms
3889
Landmark fishway
A type of pool and jet fishway formed by making the baffles perpendicular to the bottom, but oblique to the axis, and by placing a simple jet deflector close to the opening left by the baffles. Named after its designer Landmark (Norway) (illustrated)......
Similar Terms
3890
Pool and fall (drop) fishway
A fishway containing a series of step falls over which water flows during principal migration periods. The raised portion of the cross wall (transverse wall) also contains an orifice to pass fish during the remaining periods of the year......
Similar Terms
3891
Paired-obstacle fishway
A fishway that consists of a sloping rectangular channel with baffles or obstacles in opposed pairs, spaced along the channel at intervals approximately equal to the channel width, and with straight free passage between them. The free passage is considerably restricted : one-half to five-eighth of the channel width being taken up by the obstacles (.....
Similar Terms
3892
Alternate obstacle fishway, Vanes fish ladder, or Staggered-flow fish ladder
A fish ladder that consists of a straight rectangular channel with obstacles or baffles placed alternately along the sides producing a jet deflection in the horizontal plane and zigzag path to the fish (illustrated)......
Similar Terms
3893
Inclined baffle fish ladder
A fish ladder, in which the baffles are not perpendicular to the flow. This type can again be classified as `inclined baffle fish ladder - notch type`, `inclined fish ladder - orifice type`, and `inclined fish ladder - vane type`......
Similar Terms
3899
Electric fish screen
It consists of an electronic impulse generator that employs the industrial-type vacuum tube, the live electrode, and the ground conductor. The live galvanized pipe electrodes are suspended vertically to swing freely from an overhead beam or catenary cable supported by structural steel supports on each side of the canal. Random lengths of galvanized.....
Similar Terms
3900
Fish by-pass channel
A by-pass channel built downstream of the fish screen to allow an alternative route for the fish when stopped by the screens to return to the main stream......
Similar Terms
3901
Fish racks
Rack built to control movements of mature fish at irrigation structures, and used to bar upstream migrants from dangerous passage-ways, or to guide them towards traps, locks, hoists or entrances to ladders......
Similar Terms
3902
Fish traps
Devices or structures to catch upstream migrant fish for conveyance to other locations and used at entrances to pools to permit their passage only through ladders or hoisting facilities......
Similar Terms
<<    Browsing page 1 of 2    >>