scholarly journals ON THE EFFECT OF CONFIGURATIONS OF THE COAST ON THE STORM SURGES IN THE ISE BAY

2011 ◽  
Vol 1 (7) ◽  
pp. 58
Author(s):  
Kiyoshi Tanaka ◽  
Akira Murota

Wind drift is generally considered as the predominant factor of the storm surge along the sea coast. Authors noticed the fact that the duration of the wind blow of any direction is not long even at a big typhoon, while the storm surges more than 2 m are sometimes observed in the interiors of Osaka-, Ise-, and Tokyo-bay, and they have studied on another factor which might cause such water rise. A hump of water caused by a low atomospheric pressure transmits in the manner of a long wave and is deformed under the topographical effect when it comes into a bay. Authors are intending to show that the build-up of water due to topographical effect is sometimes larger than that occurring by wind drift. In this paper, the calculation was carried on neglecting the effect of wind drift and its result was compared with the observed value.

Author(s):  
Yako Harada ◽  
Yukihisa Matsumoto ◽  
Kazuho Morishita ◽  
Nobuyuki Oonishi ◽  
Kazuyoshi Kihara ◽  
...  

The vertical telescopic breakwater(VTB), which is a new breakwater that permits the navigation of ships, remain at the bottom of the sea during calm and rise to the surface during tsunamis or storm surges. Kawai et al. (2017) and Arikawa et al. (2019) found that it is effective not only for swell waves, but also for long-period waves simulating tsunamis and storm surges by previous experiments and numerical analyses. However, there have been few studies on the performance of VTB by numerical calculations in actual ports using actual typhoons. In addition, sea levels and changes in characteristics of typhoon due to climate change are predicted to occur; hence, we are concerned about the damage in all quarters caused by storm surge inundation, especially at Tokyo. Therefore, in this study, we used hypothetical typhoons under worst-case scenarios and quantitatively evaluated the protection performance of VTB against hypothetical typhoons with different aperture rates of VTB in Tokyo Bay by the numerical simulation.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/qof5ixKqIiA


Author(s):  
Sota Nakajo ◽  
Hideyuki Fujiki ◽  
Sooyoul Kim ◽  
Nobuhito Mori

In total 82 tropical cyclones data was used to determine scenarios of translation speed, minimum central pressure and track for risk assessment of storm surge at Tokyo Bay. The numerical simulation of waves and flows was conducted by solving non-linear long wave equations. The maximum surge height shows that the typhoon passing through along northeast directional track is dangerous for Tokyo Bay. This trend confirms the previous risk assessment was reasonable. However, it has been shown that the typhoon passing through along north directional track is also dangerous although the frequency is low. Especially, it is interesting that the typhoon passing through along northwest directional track causes distinctive resurgence and harbor oscillation.


Author(s):  
David F. Kelly ◽  
Ewelina Luczko ◽  
Michael Fullarton ◽  
Yahia Kala

In this paper we present the results of a multimodel approach to simulating the recent storm surges due to hurricanes Irma and Maria. The study focuses on Puerto Rico which, as a consequence of hurricane Maria, experienced storm surge around the entire perimeter of the island. In this study the storm tide is modeled using a variety of state-of-the-art 2DH numerical models. All models are based on the long wave assumption and employ the Non-Linear Shallow Water (NLSW) equations. The models vary according to the form of the governing NLSW equations that they employ. Differences include linearization and primitive variable or conserved variable (divergence) form. The numerical solution techniques used to solve the governing equations, as well as the options available for the wind, pressure, tidal forcing terms and wetting/drying techniques also vary between (and within) the models.


2011 ◽  
Vol 6 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Yoshiaki Kawata ◽  

Compound disasters are defined as double- or triplepunch disasters. As such, they cause more serious cumulative damage than individual disasters occurring independently. The independent occurrence of Tokyo metropolitan inland earthquakes is expected to kill 11,000 and cause ¥112 trillion in damage. An earthquake in Tokyo would also destroy river levees, coastal dikes, and disaster measure facilities such as water gates and locks due to liquefaction. Following such a earthquake, river flooding by the Tone and Arakawa rivers or storm surge overflow around Tokyo bay could easily occur along with strong typhoons. An Edo period (1603-1868) compound disaster involved the 1855 Ansei Edo earthquake and the 1856 Ansei Edo storm surge. With global warming progressively worsening, huge floods and storm surges are increasingly likely to occur independently. The risk that they will occur as part of a compound disaster is also increasing. Catastrophic disasters are characterized by being super-wide in area damage, compound in combining disasters, and prolonged in recovery. With the vast sea-level or low areas in Tokyo, long-term submergence due to inundation will be unavoidable. The most difficult problem, however, will be how to evacuate over 1 million people.


Author(s):  
Rikito Hisamatsu ◽  
Sooyoul Kim ◽  
Shigeru Tabeta

In recent years, refinement of stochastic storm surge estimation is essential for risk management in insurance industries because the Japanese government promotes flood risk transfer to insurance companies. Insurance systems may reach peak risk when storm surge damage occurs; however, there are only a few studies on the stochastic analysis of storm surges. This paper presents the stochastic evaluation of storm surges in Tokyo Bay. First, storm surges are assessed using two methods of an empirical formula and a numerical model. Then, the return period of storm surges is stochastically evaluated. It is found that an empirical formula underestimates the surge level in comparison to the numerical model. Based on the results of numerical model, the return period of a storm surge is proposed in Tokyo Bay.


Author(s):  
Rikito Hisamatsu ◽  
Sooyoul Kim ◽  
Shigeru Tabeta

Abstract In Japan, the fundamental disaster management plan was modified after a heavy rainfall event in 2015. According to the updated plan, the transfer of flood disaster risk to non-life insurance is promoted by the Japanese government. Thus, the importance of flood risk modeling for the insurance industry has increased. Winds are expected to become even stronger, resulting in higher storm surges, when the central pressure of the typhoon is intensified. Furthermore, it is possible for an insurance system to experience peak risk when such damage occurs simultaneously. Hence, refining the assessment method of storm surge risk is very important. An insurance company to which storm surge risk is transferred needs to assess not only the infrequent risks, for managing the risk of the company, but also the expected value of the estimated loss, for evaluating the insurance premium. However, only a few studies have assessed storm surges by stochastic approaches. In this study, storm surge losses along the coast of Tokyo Bay are predicted using the output of a stochastic typhoon model for 10,000 years. Storm surge losses due to 600 typhoons potentially causing storm surge damage for 10,000 years are calculated. Exceedance probability curves (EP curves) of estimated storm surge loss for each asset are created. Expected loss and the loss of representative return periods are evaluated based on these EP curves. We successfully determined the expected loss with a small calculation load.


Author(s):  
Rikito Hisamatsu ◽  
Rikito Hisamatsu ◽  
Kei Horie ◽  
Kei Horie

Container yards tend to be located along waterfronts that are exposed to high risk of storm surges. However, risk assessment tools such as vulnerability functions and risk maps for containers have not been sufficiently developed. In addition, damage due to storm surges is expected to increase owing to global warming. This paper aims to assess storm surge impact due to global warming for containers located at three major bays in Japan. First, we developed vulnerability functions for containers against storm surges using an engineering approach. Second, we simulated storm surges at three major bays using the SuWAT model and taking global warming into account. Finally, we developed storm surge risk maps for containers based on current and future situations using the vulnerability function and simulated inundation depth. As a result, we revealed the impact of global warming on storm surge risks for containers quantitatively.


Author(s):  
Igor Leontyev ◽  
Igor Leontyev ◽  
Tatiana Akivis ◽  
Tatiana Akivis

A model of an artificial beach is suggested for protection of coasts under erosion due to intense storm surges. It is shown that the coarser beach sand results in decrease of the beach width and growth of nourishment volume. At the same time relative material loss due to long-shore sediment transport diminishes too. The model has been applied to three sections of the coasts of Kurortny district of S.-Petersburg (eastern part of the Gulf of Finland). It recommends medium sand for the beaches construction. Modeling of extreme storms effect shows only minor deformations for designed beach profiles. For the beaches more than 1 km long even in 30-50 years more than a half of the initial beach volume conserves without additional nourishment.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1509
Author(s):  
Yuanyi Li ◽  
Huan Feng ◽  
Guillaume Vigouroux ◽  
Dekui Yuan ◽  
Guangyu Zhang ◽  
...  

A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this study, we set up a storm surge model, considering coupled effects of tides and waves on the surges. Validation against measured data shows that the coupled model is capable of simulating storm surges in the Bohai Sea. The simulation results indicate that the longshore currents, which are induced by the large gradient of radiation stress due to wave deformation, are one of the main contributors to the higher surges occurring in some coastal regions. The gently varying bathymetry is another factor contributing to these surges. With such bathymetry, the wave force direction is nearly uniform, and pushes a large amount of water in that direction. Under these conditions, the water accumulates in some parts of the coast, leading to higher surges in nearby coastal regions such as the south coast of the Bohai Bay and the west and south coasts of the Laizhou Bay. Results analysis also shows that the tidal phase at which the surge occurs influences the wave–current interactions, and these interactions are more evident in shallow waters. Neglecting these interactions can lead to inaccurate predictions of the storm surges due to overestimation or underestimation of wave-induced set-up.


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