scholarly journals Effective coastal boundary conditions for tsunami wave run-up over sloping bathymetry

2014 ◽  
Vol 1 (1) ◽  
pp. 317-369
Author(s):  
W. Kristina ◽  
O. Bokhove ◽  
E. van Groesen
Keyword(s):  
Boundary Condition ◽  
Wave Propagation ◽  
Shallow Water ◽  
Tsunami Wave ◽  
Nonlinear Phenomena ◽  
Tsunami Propagation ◽  
Effective Boundary ◽  
Daunting Task ◽  
Effective Boundary Condition ◽  
Run Up

Abstract. An effective boundary condition (EBC) is introduced as a novel technique to predict tsunami wave run-up along the coast and offshore wave reflections. Numerical modeling of tsunami propagation at the coastal zone has been a daunting task since high accuracy is needed to capture aspects of wave propagation in the more shallow areas. For example, there are complicated interactions between incoming and reflected waves due to the bathymetry and intrinsically nonlinear phenomena of wave propagation. If a fixed wall boundary condition is used at a certain shallow depth contour, the reflection properties can be unrealistic. To alleviate this, we explore a so-called effective boundary condition, developed here in one spatial dimension. From the deep ocean to a seaward boundary, i.e., in the simulation area, we model wave propagation numerically over real bathymetry using either the linear dispersive variational Boussinesq or the shallow water equations. We measure the incoming wave at this seaward boundary, and model the wave dynamics towards the shoreline analytically, based on nonlinear shallow water theory over sloping bathymetry. We calculate the run-up heights at the shore and the reflection caused by the slope. The reflected wave is then influxed back into the simulation area using the EBC. The coupling between the numerical and analytic dynamics in the two areas is handled using variational principles, which leads to (approximate) conservation of the overall energy in both areas. We verify our approach in a series of numerical test cases of increasing complexity, including a case akin to tsunami propagation to the coastline at Aceh, Sumatra, Indonesia.

scholarly journals Effective coastal boundary conditions for tsunami wave run-up over sloping bathymetry

2014 ◽  
Vol 21 (5) ◽  
pp. 987-1005 ◽  
Author(s):  
W. Kristina ◽  
O. Bokhove ◽  
E. van Groesen
Keyword(s):  
Boundary Condition ◽  
Wave Propagation ◽  
Shallow Water ◽  
Tsunami Wave ◽  
Nonlinear Phenomena ◽  
Tsunami Propagation ◽  
Effective Boundary ◽  
Daunting Task ◽  
Effective Boundary Condition ◽  
Run Up

Abstract. An effective boundary condition (EBC) is introduced as a novel technique for predicting tsunami wave run-up along the coast, and offshore wave reflections. Numerical modeling of tsunami propagation in the coastal zone has been a daunting task, since high accuracy is needed to capture aspects of wave propagation in the shallower areas. For example, there are complicated interactions between incoming and reflected waves due to the bathymetry and intrinsically nonlinear phenomena of wave propagation. If a fixed wall boundary condition is used at a certain shallow depth contour, the reflection properties can be unrealistic. To alleviate this, we explore a so-called effective boundary condition, developed here in one spatial dimension. From the deep ocean to a seaward boundary, i.e., in the simulation area, we model wave propagation numerically over real bathymetry using either the linear dispersive variational Boussinesq or the shallow water equations. We measure the incoming wave at this seaward boundary, and model the wave dynamics towards the shoreline analytically, based on nonlinear shallow water theory over bathymetry with a constant slope. We calculate the run-up heights at the shore and the reflection caused by the slope. The reflected wave is then influxed back into the simulation area using the EBC. The coupling between the numerical and analytic dynamics in the two areas is handled using variational principles, which leads to (approximate) conservation of the overall energy in both areas. We verify our approach in a series of numerical test cases of increasing complexity, including a case akin to tsunami propagation to the coastline at Aceh, Sumatra, Indonesia.

scholarly journals Estimates of Amplitude Characteristics of Tsunami Wave Run-Up in Various Areas of the Black Sea Coast

2021 ◽  
Author(s):  
A. Yu. Belokon ◽  
Keyword(s):  
Wave Propagation ◽  
Sea Level ◽  
Black Sea ◽  
Tsunami Wave ◽  
Computational Modelling ◽  
Wave Model ◽  
The Black Sea ◽  
Tsunami Propagation ◽  
Tsunami Waves ◽  
Run Up

This paper is devoted to computational modelling of tsunami wave propagation and runup to the shore for some points on the Russian, Turkish, Bulgarian and Ukrainian coasts of the Black Sea. The nonlinear long wave model was used to solve the problem of wave propagation from hydrodynamic tsunami sources, which can constitute the greatest potential danger for the studied coast areas. The hydrodynamic sources were set in the form of an elliptical elevation, the parameters of which were chosen according to the sea level response to an underwater earthquake of magnitude 7. All the sources were located in seismically active areas, where tsunamigenic earthquakes had already occurred, along the 1500 m isobath. Near each of the studied points in the area above 300 m depths, we calculated marigrams, i.e. time-series of sea level fluctuations caused by the passage of waves. Then, a one-dimensional problem of tsunami propagation and run-up on the coast was solved for each of the points under study, where the obtained marigrams were used as boundary conditions. Peculiarities of tsunami wave propagation have been shown depending on the bottom and land relief in the studied areas of the Black Sea. Estimates have been obtained of the sea level maximum rise and fall during surge and subsequent coastal drainage for the characteristic scales of relief irregularity at different points. For possible tsunamigenic earthquakes, the largest splashes may occur in the region of Yalta (2.15 m), Cide (1.9 m), Sevastopol (1.4 m), and Anapa (1.4 m). Tsunami propagation in the Feodosiya and Varna coastal areas is qualitatively similar, with maximum wave heights of 0.64 m and 0.46 m, respectively. The coastlines of Evpatoriya (0.33 m) and Odessa (0.26 m) are least affected by tsunami waves due to the extended shelf.

scholarly journals Tsunami wave propagation by voronoi diagram

2018 ◽  
Vol 7 (3) ◽  
pp. 1233
Author(s):  
V Yuvaraj ◽  
S Rajasekaran ◽  
D Nagarajan
Keyword(s):  
Wave Propagation ◽  
Voronoi Diagram ◽  
Tsunami Wave ◽  
Fast Marching Method ◽  
Coastal Regions ◽  
Fast Marching ◽  
Tsunami Waves ◽  
The Finite Difference Method ◽  
Run Up ◽  
Marching Method

Cellular automata is the model applied in very complicated situations and complex problems. It involves the Introduction of voronoi diagram in tsunami wave propagation with the help of a fast-marching method to find the spread of the tsunami waves in the coastal regions. In this study we have modelled and predicted the tsunami wave propagation using the finite difference method. This analytical method gives the horizontal and vertical layers of the wave run up and enables the calculation of reaching time.  

scholarly journals Leaky Rigid Lid: New Dissipative Modes in the Troposphere

2013 ◽  
Vol 70 (10) ◽  
pp. 3119-3127 ◽  
Author(s):  
Lyubov G. Chumakova ◽  
Rodolfo R. Rosales ◽  
Esteban G. Tabak
Keyword(s):  
Boundary Condition ◽  
Radiation Condition ◽  
Wave Radiation ◽  
Pseudodifferential Equation ◽  
Piecewise Constant ◽  
Effective Boundary ◽  
Propagating Waves ◽  
Effective Boundary Condition ◽  
Set Up ◽  
Atmospheric Phenomena

Abstract An effective boundary condition is derived for the top of the troposphere, based on a wave radiation condition at the tropopause. This boundary condition, which can be formulated as a pseudodifferential equation, leads to new vertical dissipative modes. These modes can be computed explicitly in the classical setup of a hydrostatic, nonrotating atmosphere with a piecewise constant Brunt–Väisälä frequency. In the limit of an infinitely strongly stratified stratosphere, these modes lose their dissipative nature and become the regular baroclinic tropospheric modes under the rigid-lid approximation. For realistic values of the stratification, the decay time scales of the first few modes for mesoscale disturbances range from an hour to a week, suggesting that the time scale for some atmospheric phenomena may be set up by the rate of energy loss through upward-propagating waves.

scholarly journals Study on Analytical Modelling of Tsunami Wave Propagation

2020 ◽  
Author(s):  
Yasmin Regina M ◽  
Syed Mohamed E
Keyword(s):  
Wave Propagation ◽  
Arrival Time ◽  
Tsunami Wave ◽  
Wave Train ◽  
Deep Ocean ◽  
Vital Role ◽  
The People ◽  
Run Up ◽  
Short Time ◽  
Tsunami Amplitude

Modelling of tsunami wave propagation plays a vital role in forecasting of disastrous tsunami. The earlier identification and prediction of tsunami provides more time for taking preventive measures and evacuation. On December 26, 2004, massive destruction of lives and properties due to tsunami increases the needs to develop a fast and accurate modelling of tsunami wave propagation. The modelling of waves provide the amplitude of tsunami, speed, arrival time and power of the wall of water and also run up distance and height. It also used to predict vulnerable buildings to tsunami. In this paper describes the modelling of tsunami wave propagation from generation to run-up. Numerical and analytical methods used for modelling and simulation. Tsunami is serious of wave (wave train) which has a long wavelength >500 km and celerity of wave more than 800 km/hr in deep ocean and in shallow coast, their wavelength and celerity diminishes but the amplitude of wave increases above 30m. The scope of this study is to determine the areas which are going to hit by tsunami, amplitude of wave and their arrival time for early forecasting and alert the people within a short time after an earthquake happened.

scholarly journals Numerical Investigations of Tsunami Run-Up and Flow Structure on Coastal Vegetated Beaches

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1776 ◽  
Author(s):  
Hongxing Zhang ◽  
Mingliang Zhang ◽  
Tianping Xu ◽  
Jun Tang
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Peak Flow ◽  
Tsunami Wave ◽  
Coastal Vegetation ◽  
Coastal Forest ◽  
Governing Equations ◽  
Tsunami Waves ◽  
Run Up ◽  
Sloping Beach

Tsunami waves become hazardous when they reach the coast. In South and Southeast Asian countries, coastal forest is widely utilized as a natural approach to mitigate tsunami damage. In this study, a depth-integrated numerical model was established to simulate wave propagation in a coastal region with and without forest cover. This numerical model was based on a finite volume Roe-type scheme, and was developed to solve the governing equations with the option of treating either a wet or dry wave front boundary. The governing equations were modified by adding a drag force term caused by vegetation. First, the model was validated for the case of solitary wave (breaking and non-breaking) run-up and run-down on a sloping beach, and long periodic wave propagation was investigated on a partially vegetated beach. The simulated results agree well with the measured data. Further, tsunami wave propagation on an actual-scale slope covered by coastal forest Pandanus odoratissimus (P. odoratissimus) and Casuarina equisetifolia (C. equisetifolia) was simulated to elucidate the influence of vegetation on tsunami mitigation with a different forest open gap. The numerical results revealed that coastal vegetation on sloping beach has significant potential to mitigate the impacts from tsunami waves by acting as a buffer zone. Coastal vegetation with open gaps causes the peak flow velocity at the exit of the gap to increase, and reduces the peak flow velocity behind the forest. Compared to a forest with open gaps in a linear arrangement, specific arrangements of gaps in the forest can increase the energy attenuation from tsunami wave. The results also showed that different cost-effective natural strategies in varying forest parameters including vegetation collocations, densities, and growth stages had significant impacts in reducing the severity of tsunami damage.

scholarly journals Effective boundary condition for Stokes flow over a very rough surface

2013 ◽  
Vol 254 (8) ◽  
pp. 3395-3430 ◽  
Author(s):  
Youcef Amirat ◽  
Olivier Bodart ◽  
Umberto De Maio ◽  
Antonio Gaudiello
Keyword(s):  
Boundary Condition ◽  
Rough Surface ◽  
Stokes Flow ◽  
Effective Boundary ◽  
Effective Boundary Condition
Sign in / Sign up

Export Citation Format

Share Document