Terms used in Flow Measurement

1: Discharge

It is measurement of volume of water in flowing condition. Unit of discharge are and brief description are following
(a) Cusec.
If one cubic foot volume of water is passing in one second from a certain point, then the discharge of the water is equal to 1 cusec. 1 cusec is equal to ft³/sec.
(b) Musecs/Cumec.
It is metric unit of discharge. If one cubic meter volume of water is passing in one second from a certain point then the discharge is called 1 musecs or cumec. (m³/sec.)
(c) Liter per second
If one liter of volume of water is passing in one second from a certain point discharge is called 1 L.P.S. or liter per second.
(d) Gallon per minute
If one gallon of water is passing in one minute from a certain point the volume or discharge is called G.P.M.
(e) Acre Foot
Area of one acre is completed full with the volume of water to the depth one foot, then volume of water is called acre foot (A.F.)

2: Inlet

It is the point of a hydraulic structure when water is enter in that structure.

3: Outlet

It is the point of a hydraulic structure where water is going out from that structure.

4: Upstream

The side of the flume or hydraulic structure from where water is entering in the flume or structure. In waterworks/dams side of the reservoir of water is the upstream.

5: Downstream

The side of the flume or hydraulic structure where water is going out from the flume or structure.

6: Water Allowance

It is the quantity of irrigation water allowed for 1000 acres of cultivable land.

7: Perimeter

Length of cross section or the length of a section of canal/dis tributary/watercourse which is contact with water.

8: X-Section

Cross section or x-section of channel is from which water flows. It is the distance of section i.e depth and width of flow.

9: Free Flow

When water passes through a hydraulic structure and downstream water level does not affect the water level of the upstream, flow is called free flow.

10: Submerged Flow

When water passes through a hydraulic structure and downstream water level affect on the upstream water level, flow is called submerged flow.

11: Delta of water

It is the total requirement of water of a crop from sowing time till maturity.
some Delta of water required for crops

Wheat = 16 inches                        Cotton = 28 inches                  Sugar Canes = 70 inches

Maize = 13 inches                         Rice    = 55 inches                  Potato           = 18 inches