Difference between revisions of "Weirs"

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The most common form of weir in LID practices is a rectangular weir, in the form of a [[check dam]] or flow control in a [[swale]] or other open channel.  
 
The most common form of weir in LID practices is a rectangular weir, in the form of a [[check dam]] or flow control in a [[swale]] or other open channel.  
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The flow (Q), may be calculated by measuring the height of water on the sill of the weir:
 
The flow (Q), may be calculated by measuring the height of water on the sill of the weir:
  
 
<math>Q=\frac{2}{3}C_{d}\cdot L\sqrt{2g}\cdot H^{\frac{3}{2}}</math>
 
<math>Q=\frac{2}{3}C_{d}\cdot L\sqrt{2g}\cdot H^{\frac{3}{2}}</math>
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{{Plainlist|1=Where:
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*''C<sub>d</sub>''= discharge coefficient (default 0.62 for a 'sharp edge).
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*''L'' = Length of the weir (m)
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*''g'' = Acceleration due to gravity (9.81 m/s<sup>2</sup>)
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*''H'' = Height of water over the weir (m)}}

Revision as of 17:12, 3 July 2019

The most common form of weir in LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practices is a rectangular weir, in the form of a check dam or flow control in a swale or other open channel.

The flow (Q), may be calculated by measuring the height of water on the sill of the weir\[Q=\frac{2}{3}C_{d}\cdot L\sqrt{2g}\cdot H^{\frac{3}{2}}\]

Where:

  • Cd= discharge coefficient (default 0.62 for a 'sharp edge).
  • L = Length of the weir (m)
  • g = Acceleration due to gravity (9.81 m/s2)
  • H = Height of water over the weir (m)