scholarly journals Nearshore Dynamics of Storm Surges and Waves Induced by the 2018 Typhoons Jebi and Trami Based on the Analysis of Video Footage Recorded on the Coasts of Wakayama, Japan

2019 ◽  
Vol 7 (11) ◽  
pp. 413 ◽  
Author(s):  
Yusuke Yamanaka ◽  
Yoshinao Matsuba ◽  
Yoshimitsu Tajima ◽  
Ryotaro Shibata ◽  
Naohiro Hattori ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Storm Surges ◽  
Special Focus ◽  
Field Surveys ◽  
Video Footage ◽  
Local Wave ◽  
Nearshore Waves ◽  
Survey Results ◽  
Run Up ◽  
Coastal Damage

In this study, field surveys along the coasts of Wakayama Prefecture, Japan, were first conducted to investigate the coastal damage due to storm surges and storm-induced waves caused by the 2018 Typhoons Jebi and Trami. Special focus was placed on the characteristic behavior of nearshore waves through investigation of observed data, numerical simulations, and image analysis of video footage recorded on the coasts. The survey results indicated that inundation, wave overtopping, and drift debris caused by violent storm-induced waves were the dominant factors causing coastal damage. Results of numerical simulations showed that heights of storm-induced waves were predominantly greater than storm surge heights along the entire coast of Wakayama in both typhoons. However, computed gradual alongshore variations in wave and surge heights did not explain locally-concentrated inundation and run-up heights observed along the coasts. These results indicate that complex nearshore hydrodynamics induced by local nearshore bathymetry might have played a significant role in inducing such local wave characteristics and the associated coastal damage. Analysis of video footage recorded during Typhoon Jebi, for example, clearly showed evidence of amplified infragravity wave components, which could enhance inundation and wave run-up.

Statistical analysis and modeling to examine the exterior and interior building damage pertaining to the 2016 Kumamoto earthquake

2021 ◽  
pp. 875529302110354
Author(s):  
Haoyi Xiu ◽  
Takayuki Shinohara ◽  
Masashi Matsuoka ◽  
Munenari Inoguchi ◽  
Ken Kawabe ◽  
...  
Keyword(s):  
Decision Making ◽  
Assessment Procedure ◽  
Field Surveys ◽  
The 2016 Kumamoto Earthquake ◽  
Damage Grade ◽  
Damage Grades ◽  
Distinct Stage ◽  
Survey Results ◽  
The Relationship ◽  
Post Disaster

After an earthquake occurs, field surveys are conducted by relevant authorities to assess the damage suffered by buildings. The field survey is essential as it ensures the safety of residents and provides the necessary information to local authorities for post-disaster recovery. In Japan, a primary (mandatory) exterior survey is conducted first, and a secondary (voluntary) interior survey is performed subsequently if the residents request a reinvestigation. However, a major challenge associated with field surveys is the substantial time cost of determining the damage grades. Moreover, an interior survey is performed only after receiving the reinvestigation request from occupants, which further delays the decision-making process. In addition, the risk of incorrect damage estimation during the exterior survey must be considered because underestimating the damage can endanger the residents. Therefore, in this study, a three-part analysis (Parts I–III), where each part corresponds to a distinct stage of the standard damage assessment procedure, was performed to characterize the relationship between the building parameters and damage grades at different stages. To further explore the possibility of accelerating decision-making, predictive modeling was performed in each part. The Part I results indicate that estimating the final damage grade for all buildings immediately after the exterior survey is similar to treating the exterior survey results as the final ones. The Part II results show that buildings that potentially require an interior survey can be predicted with reasonable accuracy after the exterior survey. In buildings for which reinvestigations have been requested, Part III demonstrates that the risk of underestimation in the exterior survey can be predicted reliably.

scholarly journals COMPARISON OF STORM SURGE DISASTERS IN ASIA

2011 ◽  
Vol 1 (32) ◽  
pp. 18
Author(s):  
Tomoya Shibayama
Keyword(s):  
Storm Surge ◽  
River Mouth ◽  
Storm Surges ◽  
Damage Development ◽  
Field Surveys ◽  
Counter Measures ◽  
Physical Mechanisms ◽  
Cyclone Sidr ◽  
The Difference ◽  
Cyclone Nargis

Field surveys were performed in the southwest of Bangladesh after cyclone Sidr in 2007 and in Yangon River Basin after Cyclone Nargis in Myanmar in 2008 in order to learn lessons out of severe disasters due to cyclones. Spatial distributions of inundation heights were measured around the most damaged areas. Both Bangladesh and Myanmar were severely damaged, but the preparedness against storm surge and the experiences were different. The resultant total losses in these two countries were significantly different. In Bangladesh, many people witnessed that storm surges inundated with bore-like waves. Counter measured against storm surges should account for the physical mechanisms for the development of such bore-like waves and possible damages due to such waves. Embankment showed significant roles to minimize the damage. Development of riverbanks especially around the river mouth is one of most essential counter-measures to be carried out in Bangladesh. Shelter functioned well to save significant number of lives in Bangladesh. But in Myanmar, there were few experiences on storm surge and no countermeasures such as shelters. These differences results the difference of losses. They were 4,232 including deaths and unknowns in Bangladesh but 138,373 in Myanmar.

scholarly journals Post-event field survey of 28 September 2018 Sulawesi earthquake and tsunami

2019 ◽  
Vol 19 (12) ◽  
pp. 2781-2794 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Purwanto B. Santoso ◽  
Shih-Chun Hsiao ◽  
Rudy T. Imananta
Keyword(s):  
Field Survey ◽  
Severe Damage ◽  
Arrival Times ◽  
Tsunami Waves ◽  
Tsunami Measurements ◽  
Survey Results ◽  
Earthquake Event ◽  
Run Up ◽  
2018 Sulawesi Earthquake ◽  
Made In

Abstract. An earthquake with a magnitude of Mw=7.5 that occurred in Sulawesi, Indonesia, on 28 September 2018 triggered liquefaction and tsunamis that caused severe damage and many casualties. This paper reports the results of a post-tsunami field survey conducted by a team with members from Indonesia and Taiwan that began 13 d after the earthquake. The main purpose of this survey was to measure the run-up of tsunami waves and inundation and observe the damage caused by the tsunami. Measurements were made in 18 selected sites, most in Palu Bay. The survey results show that the run-up height and inundation distance reached 10.7 m in Tondo and 488 m in Layana. Inundation depths of 2 to 4 m were common at most sites and the highest was 8.4 m in Taipa. The arrival times of the tsunami waves were quite short and different for each site, typically about 3–8 min from the time of the main earthquake event. This study also describes the damage to buildings and infrastructure and coastal landslides.

scholarly journals Study on Fluorine Pollution in a Slag Yard

2019 ◽  
Vol 9 (5) ◽  
pp. 847
Author(s):  
Lide Wei ◽  
Changfu Wei ◽  
Sugang Sui
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Numerical Simulations ◽  
Solute Transport ◽  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Laboratory Studies ◽  
Survey Results ◽  
Simulation Results

This paper suggests a large-scale three-dimensional numerical simulation method to investigate the fluorine pollution near a slag yard. The large-scale three-dimensional numerical simulation method included an experimental investigation, laboratory studies of solute transport during absorption of water by soil, and large-scale three-dimensional numerical simulations of solute transport. The experimental results showed that the concentrations of fluorine from smelting slag and construction waste soil were well over the discharge limit of 0.1 kg/m3 recommended by Chinese guidelines. The key parameters of the materials used for large-scale three-dimensional numerical simulations were determined based on an experimental investigation, laboratory studies, and soil saturation of survey results and back analyses. A large-scale three-dimensional numerical simulation of solute transport was performed, and its results were compared to the experiment results. The simulation results showed that the clay near the slag had a high saturation of approximately 0.9, consistent with the survey results. Comparison of the results showed that the results of the numerical simulation of solute transport and the test results were nearly identical, and that the numerical simulation results could be used as the basis for groundwater environmental evaluation.

scholarly journals On the spatial segregation of helicity by inertial waves in dynamo simulations and planetary cores

2018 ◽  
Vol 851 ◽  
pp. 268-287 ◽  
Author(s):  
P. A. Davidson ◽  
A. Ranjan
Keyword(s):  
Numerical Simulations ◽  
Strongly Correlated ◽  
Inertial Waves ◽  
The South ◽  
The North ◽  
Planetary Cores ◽  
Local Wave ◽  
Wave Flux ◽  
The Relationship

The distribution of kinetic helicity in a dipolar planetary dynamo is central to the success of that dynamo. Motivated by the helicity distributions observed in numerical simulations of the Earth’s dynamo, we consider the relationship between the kinetic helicity, $h=\boldsymbol{u}\boldsymbol{\cdot }\unicode[STIX]{x1D735}\times \boldsymbol{u}$, and the buoyancy field that acts as a source of helicity, where $\boldsymbol{u}$ is velocity. We show that, in the absence of a magnetic field, helicity evolves in accordance with the equation $\unicode[STIX]{x2202}h/\unicode[STIX]{x2202}t=-\unicode[STIX]{x1D735}\boldsymbol{\cdot }\boldsymbol{F}+S_{h}$, where the flux, $\boldsymbol{F}$, represents the transport of helicity by inertial waves, and the helicity source, $S_{h}$, involves the product of the buoyancy and the velocity fields. In the numerical simulations it is observed that the helicity outside the tangent cylinder is predominantly negative in the north and positive in the south, a feature which the authors had previously attributed to the transport of helicity by waves (Davidson & Ranjan, Geophys. J. Intl, vol. 202, 2015, pp. 1646–1662). It is also observed that there is a strong spatial correlation between the distribution of $h$ and of $S_{h}$, with $S_{h}$ also predominantly negative in the north and positive in the south. This correlation tentatively suggests that it is the in situ generation of helicity by buoyancy that establishes the distribution of $h$ outside the tangent cylinder, rather than the dispersal of helicity by waves, as had been previously argued by the authors. However, although $h$ and $S_{h}$ are strongly correlated, there is no such correlation between $\unicode[STIX]{x2202}h/\unicode[STIX]{x2202}t$ and $S_{h}$, as might be expected if the distribution of $h$ were established by an in situ generation mechanism. We explain these various observations by showing that inertial waves interact with the buoyancy field in such a way as to induce a source $S_{h}$ which has the same sign as the helicity in the local wave flux, and that the sign of $h$ is simply determined by the direction of that flux. We conclude that the observed distributions of $h$ and $S_{h}$ outside the tangent cylinder are consistent with the transport of helicity by waves.

scholarly journals Characteristics of Damages of Severe Local Storms Based on Field Surveys in Bangladesh

2013 ◽  
Vol 8 (6) ◽  
pp. 1052-1060
Author(s):  
Yusuke Yamane ◽  
◽  
Masashi Kiguchi ◽  
Taiichi Hayashi ◽  
Ashraf M. Dewan ◽  
...  
Keyword(s):  
Field Survey ◽  
Storm Damage ◽  
Field Surveys ◽  
Local Areas ◽  
Survey Results ◽  
Local Residents ◽  
Meteorological Features

This paper presents field survey results on damage from severe local storms, such as tornadoes. Surveys were conducted in Bangladesh in August 2009 and August 2010 to clarify damage details, meteorological features, factors related to damage generation and spread, recovery problems experienced by local residents due to storm damage and storms prediction in local areas.

Wave overtopping and splash-up at seawalls with bullnose

2020 ◽  
Vol 20 (3) ◽  
pp. 333-342
Author(s):  
Le Hai Trung ◽  
Dang Thi Linh ◽  
Tang Xuan Tho ◽  
Nguyen Truong Duy ◽  
Tran Thanh Tung
Keyword(s):  
Storm Surges ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Wave Overtopping ◽  
Run Up ◽  
Coast Of Vietnam ◽  
Small Scale Model ◽  
Wall Interactions

Seawalls have been erected to protect hundreds of towns and tourism areas stretching along the coast of Vietnam. During storm surges or high tides, wave overtopping and splash-up would often threaten the safety of infrastructures, traffic and residents on the narrow land behind. Therefore, this study investigates these wave-wall interactions via hydraulic small scale model tests at Thuyloi University. Remarkably, the structure models were shaped to have different seaward faces and bullnoses. The wave overtopping discharge and splash run-up height at seawalls with bullnose are significantly smaller than those without bullnose. Furthermore, the magnitude of these decreasing effects is quantitatively estimated.

The 2018 Palu Tsunami: Coeval Landslide and Coseismic Sources

2020 ◽  
Vol 91 (6) ◽  
pp. 3148-3160
Author(s):  
Amy L. Williamson ◽  
Diego Melgar ◽  
Xiaohua Xu ◽  
Christopher Milliner
Keyword(s):  
Survey Data ◽  
Field Survey ◽  
Tide Gauge ◽  
Hazard Analysis ◽  
Strike Slip ◽  
Coseismic Deformation ◽  
Coseismic Slip ◽  
Video Footage ◽  
Run Up ◽  
Tsunami Model

Abstract On 28 September 2018, Indonesia was struck by an MW 7.5 strike-slip earthquake. An unexpected tsunami followed, inundating nearby coastlines leading to extensive damage. Given the traditionally non-tsunamigenic mechanism, it is important to ascertain if the source of the tsunami is indeed from coseismic deformation, or something else, such as shaking induced landsliding. Here we determine the leading cause of the tsunami is a complex combination of both. We constrain the coseismic slip from the earthquake using static offsets from geodetic observations and validate the resultant “coseismic-only” tsunami to observations from tide gauge and survey data. This model alone, although fitting some localized run-up measurements, overall fails to reproduce both the timing and scale of the tsunami. We also model coastal collapses identified through rapidly acquired satellite imagery and video footage as well as explore the possibility of submarine landsliding using tsunami raytracing. The tsunami model results from the landslide sources, in conjunction with the coseismic-generated tsunami, show a greatly improved fit to both tide gauge and field survey data. Our results highlight a case of a damaging tsunami the source of which is a complex mix of coseismic deformation and landsliding. Tsunamis of this nature are difficult to provide warning for and are underrepresented in regional tsunami hazard analysis.

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