Storm Surge Estimation Along Tokyo Bay Based on a Simple Stochastic Approach

2018 ◽  
Author(s):  
Rikito Hisamatsu ◽  
Sooyoul Kim ◽  
Shigeru Tabeta
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Return Period ◽  
Empirical Formula ◽  
Stochastic Analysis ◽  
Storm Surges ◽  
Stochastic Approach ◽  
Insurance Companies ◽  
Tokyo Bay ◽  
Risk Transfer

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.

scholarly journals APPLICABILITY OF THE VERTICAL TELESCOPIC BREAKWATER USING THE PAST TYPHOON IN TOKYO BAY

2020 ◽  
pp. 35
Author(s):  
Yako Harada ◽  
Yukihisa Matsumoto ◽  
Kazuho Morishita ◽  
Nobuyuki Oonishi ◽  
Kazuyoshi Kihara ◽  
...  
Keyword(s):  
Climate Change ◽  
Storm Surge ◽  
Storm Surges ◽  
Numerical Calculations ◽  
Numerical Analyses ◽  
Tokyo Bay ◽  
Worst Case ◽  
Sea Levels ◽  
Long Period ◽  
The Past

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

scholarly journals Storm-induced sediment supply to coastal dunes on sand flats

2020 ◽  
Vol 8 (2) ◽  
pp. 335-350 ◽  
Author(s):  
Filipe Galiforni-Silva ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Storm Surges ◽  
Coastal Dunes ◽  
Sediment Supply ◽  
Aeolian Transport ◽  
Sand Flat ◽  
Sediment Transfer ◽  
Sand Flats

Abstract. Growth of coastal dunes requires a marine supply of sediment. Processes that control the sediment transfer between the subtidal and the supratidal zone are not fully understood, especially in sand flats close to inlets. It is hypothesised that storm surge events induce sediment deposition on sand flats, providing fresh material for aeolian transport and dune growth. The objective of this study is to identify which processes cause deposition on the sand flat during storm surge conditions and discuss the relationship between the supratidal deposition and sediment supply to the dunes. We use the island of Texel (NL) as a case study, of which multiannual topographic and hydrographic datasets are available. Additionally, we use the numerical model XBeach to simulate the most frequent storm surge events for the area. Results show that supratidal shore-parallel deposition of sand occurs in both the numerical model and the topographic data. The amount of sand deposited is directly proportional to surge level and can account for more than a quarter of the volume deposited at the dunes yearly. Furthermore, storm surges are also capable of remobilising the top layer of sediment of the sand flat, making fresh sediment available for aeolian transport. Therefore, in a sand flat setting, storm surges have the potential of reworking significant amounts of sand for aeolian transport in periods after the storm and as such can also play a constructive role in coastal dune development.

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
Keyword(s):  
Storm Surge ◽  
Storm Surges ◽  
Tokyo Bay ◽  
Wind Drift ◽  
Long Wave ◽  
Water Rise ◽  
Predominant Factor ◽  
Topographical Effect ◽  
Wind Blow ◽  
Sea Coast

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.

Downfall of Tokyo due to Devastating Compound Disaster

2011 ◽  
Vol 6 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Yoshiaki Kawata ◽  
Keyword(s):  
Global Warming ◽  
Sea Level ◽  
Storm Surge ◽  
Storm Surges ◽  
Difficult Problem ◽  
Tokyo Bay ◽  
Edo Period ◽  
River Flooding ◽  
Compound Disaster

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.

Water movement and the simulation of storm surges in the Firth of Clyde

1986 ◽  
Vol 90 ◽  
pp. 85-96
Author(s):  
John M. Townson ◽  
Richard H. F. Collar
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
General Circulation ◽  
Water Movement ◽  
Storm Surges ◽  
Equation Of Motion ◽  
Relative Importance

SynopsisThe basic mechanisms governing the general circulation of water in the Firth of Clyde are reviewed with particular reference to their changing relative importance throughout the system, this including the inner estuary. Attention is then focused on the effect of storm surge. A numerical model for the depth-integrated equation of motion is applied to the surges recorded in 1972 and 1979. The proportion of surge generated within the outer firth is thereby assessed.

scholarly journals Maximum Storm Tide Response to the Intensity of Typhoons and Bathymetric Changes along the East Coast of Taiwan

2017 ◽  
Author(s):  
Wen-Cheng Liu ◽  
Wei-Bo Chen ◽  
Lee-Yaw Lin
Keyword(s):  
Storm Surge ◽  
Return Period ◽  
East Coast ◽  
Storm Surges ◽  
Measured Data ◽  
Water Levels ◽  
Storm Tide ◽  
Astronomical Tide ◽  
Extreme Flooding ◽  
Bathymetric Changes

A typhoon-induced storm surge is considered one of the most severe coastal disasters in Taiwan. However, the combination of the storm surge and the astronomical tide called the storm tide can actually cause extreme flooding in coastal areas. This study implemented a two-dimensional hydrodynamic model to account for the interaction between tides and storm surges on the coast of Taiwan. The model was validated with observed water levels at Sauo Fish Port, Hualien Port, and Chenggong Fish Port under different historical typhoon events. The model results are in reasonable agreement with the measured data. The validated model was then used to evaluate the effects of the typhoon's intensity, bathymetric change, and the combination of the typhoon’s intensity and bathymetric change on the maximum storm tide and its distribution along the east coast of Taiwan. The results indicated that the maximum storm tide rises to 1.92 m under a typhoon with an intensity of a 100-year return period. The maximum storm tide increased from a baseline of 1.26 m to 2.63 m for a 90% bathymetric rise at Sauo Fish Port under the conditions of Typhoon Jangmi (2008). The combination of the intensity of a typhoon with a 100-year return period and a 90% bathymetric rise will result in a maximum storm tide exceeding 4 m, 2 m, and 3 m at Sauo Fish Port, Hualien Port, and Chenggong Fish Port, respectively. We also found that the distribution of the maximum storm tide on the east coast of Taiwan can expand significantly subject to the bathymetric rise.

scholarly journals FREQUENCY OF OCCURRENCE OF STORM SURGES IN AN ESTUARY: A STOCHASTIC APPROACH

1984 ◽  
Vol 1 (19) ◽  
pp. 14
Author(s):  
Marc Sas
Keyword(s):  
Storm Surge ◽  
Joint Probability ◽  
Extreme Value Distribution ◽  
Simulation Models ◽  
Storm Surges ◽  
Stochastic Approach ◽  
Frequency Of Occurrence ◽  
Basic Principles ◽  
Probability Methods ◽  
A New Technique

This paper presents the results of a study on the frequency of occurrence of storm surge levels in the river Scheldt at Antwerp, related to the design of a storm surge barrier and the evaluation of the dike safety in the Scheldt basin. The basic principles of the extreme value distribution methods, the joint probability methods and simulation models are examined. A new technique, based upon the simulation of storms by variables characterizing the resulting surge is proposed. Results are compared with those of other methods.

scholarly journals Storm-induced sediment supply to coastal dunes on sand flats

2019 ◽  
Author(s):  
Filipe Galiforni Silva ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Storm Surges ◽  
Coastal Dunes ◽  
Sediment Supply ◽  
Data Sets ◽  
Aeolian Transport ◽  
Tidal Zone ◽  
Sand Flat ◽  
Sand Flats

Abstract. Marine supply of sand can control the development and morphology of coastal dunes. However, processes that control the sediment transfer between sub-tidal and the supra-tidal zone are not fully understood, especially in coastal settings such as sand-flats close to inlets. It is hypothesised that storm surge events induce sediment deposition on sand-flats, so that this may influence dune development significantly. Therefore, the objective of this study is to identify which processes causes deposition on the sand-flat during storm-surge conditions and discuss the relation between the supra-tidal deposition and sediment supply to the dunes. We use the island of Texel as a case study, on which multi-annual topographic and hydrographic data sets are available. Additionally, we use the numerical model XBeach to simulate the most frequent storm surge events for the area. Results show that a supra-tidal shore-parallel deposition of sand occurs in both the numerical model and the data. The amount of sand deposition is directly proportional to surge level, and can account for more than half of the volume deposited at the dunes on a yearly basis. Furthermore, storms are also capable of remobilising the top layer of sediment of the sand-flat, making fresh sediment available for aeolian transport. Therefore, in a sand-flat setting, storm surges have the potential of adding significant amounts of sand for aeolian transport in periods after the storm, suggesting that storms play a significant role in the onshore sand supply between sub-tidal and subaerial zones in those areas.

Estimation of Expected Loss by Storm Surges Along Tokyo Bay Coast

2019 ◽  
Author(s):  
Rikito Hisamatsu ◽  
Sooyoul Kim ◽  
Shigeru Tabeta
Keyword(s):  
Storm Surge ◽  
Storm Surges ◽  
Assessment Method ◽  
Insurance Premium ◽  
Tokyo Bay ◽  
Heavy Rainfall Event ◽  
Exceedance Probability ◽  
Insurance Company ◽  
Risk Modeling ◽  
Expected Loss

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.

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