Difference between revisions of "Wave run-up"

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<math>R = \eta_u + H \xi  ,</math>
 
<math>R = \eta_u + H \xi  ,</math>
  
where <math>\eta_u</math> is the [[wave set-up]], <math>H</math> is the offshore wave height  and <math>\xi</math> is the wave similarity parameter,
+
where <math>\eta_u</math> is the [[wave set-up]], <math>H</math> is the offshore wave height  and <math>\xi</math> is the [[surf similarity parameter]],
  
 
<math>\xi = \Large\frac{\tan \beta}{\sqrt{H/L}}\normalsize = T \tan \beta  \Large\sqrt{\frac{g}{4\pi H}}\normalsize , </math>
 
<math>\xi = \Large\frac{\tan \beta}{\sqrt{H/L}}\normalsize = T \tan \beta  \Large\sqrt{\frac{g}{4\pi H}}\normalsize , </math>

Revision as of 23:08, 3 April 2021

Definition of Wave run-up:
Wave run-up is the maximum onshore elevation reached by waves, relative to the shoreline position in the absence of waves.
This is the common definition for Wave run-up, other definitions can be discussed in the article


Notes

Wave run-up is an important parameter for assessing the safety of sea dikes or coastal settlements. Wave run-up is the sum of wave set-up and swash uprush (see Swash zone dynamics) and must be added to the water level reached as a result of tides and wind set-up.

By waves is meant: waves generated by wind (locally or on the ocean) or waves generated by incidental disturbances of the sea surface such as tsunamis, seiches or ship waves. Wave run-up is often indicated with the sympol [math] R [/math].

For waves collapsing on the beach, the wave run-up can be estimated to first approximation with the formula of Hunt (1959) [1],

[math]R = \eta_u + H \xi ,[/math]

where [math]\eta_u[/math] is the wave set-up, [math]H[/math] is the offshore wave height and [math]\xi[/math] is the surf similarity parameter,

[math]\xi = \Large\frac{\tan \beta}{\sqrt{H/L}}\normalsize = T \tan \beta \Large\sqrt{\frac{g}{4\pi H}}\normalsize , [/math]

where [math]L = g T^2/(2 \pi)[/math] is the offshore wave length, [math]\beta[/math] is the beach slope and [math]T[/math] is the wave period. The horizontal wave incursion is approximately given by [math] R / \tan \beta[/math].


Related articles

Swash zone dynamics
Wave set-up
Swash
Tsunami


References

  1. Hunt, I.A. 1959. Design of seawalls and breakwaters. J. Waterw. Harbors Division ASCE 85: 123–152