# Difference between revisions of "Flow in a swale"

From LID SWM Planning and Design Guide

Jenny Hill (talk | contribs) m |
Jenny Hill (talk | contribs) m |
||

Line 1: | Line 1: | ||

− | [[File:Swale_sections.PNG|frameless|300 px]] | + | {{float right|[[File:Swale_sections.PNG|frameless|300 px]]}} |

Flow (''Q'') in an open channel, such as a [[swale]], may be calculated using Manning's equation: | Flow (''Q'') in an open channel, such as a [[swale]], may be calculated using Manning's equation: | ||

<math>Q=VA=\frac{R^{\frac{2}{3}}S^{\frac{1}{2}}}{n}</math> | <math>Q=VA=\frac{R^{\frac{2}{3}}S^{\frac{1}{2}}}{n}</math> |

## Revision as of 17:26, 3 July 2019

Flow (*Q*) in an open channel, such as a swale, may be calculated using Manning's equation\[Q=VA=\frac{R^{\frac{2}{3}}S^{\frac{1}{2}}}{n}\]
Where\[R=\frac{A}{P}\]

Where:

*Q*= the flow in the swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades. (m^{3}/s)*A*= the cross sectional area of the swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades. (m^{2})*P*= the wetted perimeter of the swaleA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades. (m)*S*= the longitudinal slope (m/m)*n*= Manning's coefficient (dimensionless)