Extreme Event Return Period Modules

Calculate extreme event amplitude and return period from return period data using the Weibull, Gumbel and Frechet probability distributions.

A best fit line is calculated for the data points using the least squares linear regression method. The regression is calculated for X versus Z instead of Z versus X (the X and Z values are swapped). The three parameter distribution amplitude offset is a minimum amplitude. The regression data points and regression parameters are displayed in the output view at the bottom of the page. Use the Data Plot option on the plot bar to display the data points and the best fit line.

Change Module :

• Maths Probability Calculation Module
• All

Related Modules :

• Maths Linear Regression Calculation Module
• Ocean Wave Shoaling And Wave Height Calculation Module

Calculate ocean wave and current velocity and acceleration for Airy, Stokes, cnoidal and JONSWAP waves.

Wave velocity and acceleration can be calculated for Airy, Stokes, and Cnoidal waves. The recommended wave type is displayed below the calc bar. Use the Result Plot option to compare the Airy, Stokes, and cnoidal wave profiles. The seabed significant wave velocity and zero upcrossing period can be calculated from the JONSWAP surface spectrum.

Current velocity can be calculated near the seabed using either the logarithmic profile, or the 1/7th power law profile. The logarithmic and power law profiles are not valid For large elevations above the seabed.

Note : The Stokes and cnoidal waves use trucated infinite series. Under certain conditions the truncated series do not converge properly. The Stokes wave is not suitable for shallow water waves. The cnoidal wave is not suitable for deep water waves. The recommended wave type is displayed below the calc bar. The JONSWAP wave uses an Airy wave transfer function to calculate seabed velocity. The JONSWAP wave is not suitable for very shallow waves (near breaking).

Change Module :

• Breaking Wave Height Calculation Module
• Ocean Wave And Current Seabed Stability Calculation Module
• Ocean Wave And Current Self Burial Calculation Module
• Ocean Wave Dimensionless Number Calculation Module
• Ocean Wave Directionality And Spreading Calculation Module
• Ocean Wave Maximum Wave Height Calculation Module
• Ocean Wave Shoaling And Wave Height Calculation Module
• Ocean Wave Theory Selection Airy Stokes And Cnoidal Waves Calculation Module
• Ocean Wave Velocity And Acceleration Calculation Module
• All
• More Ocean Waves Modules

Calculate ocean wave shoaling wave height from water depth.

Shoaling occurs as the water depth decreases or becomes more shallow. the wave length and celerity decrease (the wave becomes slower), and the wave height increases. The wave energy flux is assumed to be constant. For Airy waves the wave energy flux is proportional to c H^2 (the wave celerity times the wave height squared). The same relationship is assumed to also apply to Stokes and cnoidal waves. Use the Result Plot option to compare the initial wave and shoaling wave profiles, or the wave height versus water depth for Airy, Stokes and cnoidal waves. The recommended wave type is displayed below the calc bar.

Note : The Stokes wave is the most suitable for a transtion from deep water to shallow water waves. The cnoidal wave is not suitable for deep water waves. The Airy wave is not suitable for shallow water waves.

Change Module :

• Breaking Wave Height Calculation Module
• Ocean Wave And Current Seabed Stability Calculation Module
• Ocean Wave And Current Self Burial Calculation Module
• Ocean Wave And Current Velocity And Acceleration Calculation Module
• Ocean Wave Dimensionless Number Calculation Module
• Ocean Wave Directionality And Spreading Calculation Module
• Ocean Wave Maximum Wave Height Calculation Module
• Ocean Wave Theory Selection Airy Stokes And Cnoidal Waves Calculation Module
• Ocean Wave Velocity And Acceleration Calculation Module
• All
• More Wave Height Modules

Calculate ocean current velocity from return period data using the Weibull, Gumbel or Frechet probability distributions.

The three parameter distribution and Z offset is used to account for a minimum value, the smallest event which can occur in any sample period. The best fit line is calculated for the data points using the least squares linear regression method. The regression is calculated for return period versus amplitude (the X and Z values are swapped). Use the Data Plot option on the plot bar to display the data points and the calculated best fit. The regression data points and regression parameters are displayed in the output view at the bottom of the page.

Change Module :

• Ocean Wave And Current Probability And Return Period Calculation Module
• Ocean Wave Probability And Return Period Calculation Module
• All

Related Modules :

• JONSWAP Wave Spectrum Calculation Module
• More Wave Probability Modules

Calculate JONSWAP seabed wave and current amplitude from return period data.

Return period data can be analysed using either the Weibull, Gumbel or Frechet distribution. Current velocity can be calculated using either the logarithmic profile, or the 1/7th power law profile. The logarithmic and power law profiles are only valid in the boundary layer on or near the seabed. The seabed velocity and upcrossing period is calculated from the JONSWAP surface spectrum using a first order Airy wave transformation. The calculation may not be valid in shallow water, and is not recommended for elevations greater than half the water depth.

Reference : Hasselmann K et al : Measurements of Wind-Wave Growth And Swell Decay During The Joint North Sea Wave Project (JONSWAP)

Change Module :

• JONSWAP Wave Directionality And Spreading Calculation Module
• JONSWAP Wave Spectrum Calculation Module
• JONSWAP Wave Velocity And Period Calculation Module
• All
• More JONSWAP Modules
• More Ocean Waves Modules