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  2. Standard step method - Wikipedia

    en.wikipedia.org/wiki/Standard_Step_Method

    During uniform flow, the flow depth is known as normal depth (yn). This depth is analogous to the terminal velocity of an object in free fall, where gravity and frictional forces are in balance (Moglen, 2013). [3] Typically, this depth is calculated using the Manning formula. Gradually varied flow occurs when the change in flow depth per change ...

  3. Available water capacity - Wikipedia

    en.wikipedia.org/wiki/Available_water_capacity

    It is also known as available water content (AWC), profile available water (PAW) [2] or total available water (TAW). The concept, put forward by Frank Veihmeyer and Arthur Hendrickson, [ 3 ] assumed that the water readily available to plants is the difference between the soil water content at field capacity ( θ fc ) and permanent wilting point ...

  4. Discharge (hydrology) - Wikipedia

    en.wikipedia.org/wiki/Discharge_(hydrology)

    A discharge is a measure of the quantity of any fluid flow over unit time. The quantity may be either volume or mass. Thus the water discharge of a tap (faucet) can be measured with a measuring jug and a stopwatch. Here the discharge might be 1 litre per 15 seconds, equivalent to 67 ml/second or 4 litres/minute. This is an average measure.

  5. Parshall flume - Wikipedia

    en.wikipedia.org/wiki/Parshall_flume

    Only the upstream depth needs to be measured to calculate the flow rate. A free flow also induces a hydraulic jump downstream of the flume. Submerged flow occurs when the water surface downstream of the flume is high enough to restrict flow through a flume, submerged flume conditions exist. A backwater buildup effect occurs in a submerged flume.

  6. Drainage equation - Wikipedia

    en.wikipedia.org/wiki/Drainage_equation

    the permissible long term average depth of the water table (Dw) on the basis of agricultural drainage criteria; the soil's hydraulic conductivity (Ka and Kb) by measurements; the depth of the bottom of the aquifer (Di) the design drain spacing (L) can be found from the equation in dependence of the drain depth (Dd) and drain radius (r ...

  7. Under keel clearance - Wikipedia

    en.wikipedia.org/wiki/Under_keel_clearance

    At a basic level, it is typically calculated in metres using the formula: [1] UKC = Charted Depth − Draft-/+ Height of Tide. Ship masters and deck officers can obtain the depth of water from Electronic navigational charts. [5] More dynamic or advanced calculations include safety margins for manoeuvring effects and squat. [7]

  8. Hydraulic diameter - Wikipedia

    en.wikipedia.org/wiki/Hydraulic_diameter

    For the limiting case of a very wide duct, i.e. a slot of width b, where b ≫ a, and a is the water depth, then D H = 4a. For a fully filled duct or pipe whose cross-section is a convex regular polygon , the hydraulic diameter is equivalent to the diameter D {\displaystyle D} of a circle inscribed within the wetted perimeter .

  9. Drawdown (hydrology) - Wikipedia

    en.wikipedia.org/wiki/Drawdown_(hydrology)

    Hydraulic head (or piezometric head) is a specific measurement of the potential of water above a vertical datum. [7] It is the height of the free surface of water above a given point beneath the surface. [4] Pumping level is the level of water in the well during pumping. [8] Specific capacity is the well yield per unit of drawdown. [8]