Pub Date : 2022-10-02DOI: 10.1080/21664250.2022.2139918
K. Goda
ABSTRACT This study presents new stochastic source models for the Cascadia subduction earthquakes in the Pacific Northwest, which can trigger massive tsunamis along the shoreline of Vancouver Island. An extensive set of 5,000 stochastic source models is generated for the moment magnitude ranges between 8.1 and 9.1, and regional tsunami hazard simulations are performed at the grid resolution of 270 m. The results from the stochastic tsunami simulations are characterized by evaluating the regional tsunami hazard metric that is based on the geometric mean of the maximum wave heights along the Vancouver Island coast. Subsequently, using the probability distribution of the regional tsunami hazard parameter, representative source models are identified by capturing the average as well as rare rupture cases and then detailed tsunami hazard results, such as maximum wave height maps and wave profiles at specific locations, are examined. Numerical results highlight the directivity effects of tsunami generation and wave propagation on tsunami hazards along the Canadian Pacific coast and the earthquake source characterizations in terms of fault geometry and earthquake slip distribution. The developed source models and tsunami simulation results serve as the first step for performing probabilistic tsunami hazard analysis for the Cascadia subduction zone.
{"title":"Stochastic source modeling and tsunami simulations of cascadia subduction earthquakes for Canadian Pacific coast","authors":"K. Goda","doi":"10.1080/21664250.2022.2139918","DOIUrl":"https://doi.org/10.1080/21664250.2022.2139918","url":null,"abstract":"ABSTRACT This study presents new stochastic source models for the Cascadia subduction earthquakes in the Pacific Northwest, which can trigger massive tsunamis along the shoreline of Vancouver Island. An extensive set of 5,000 stochastic source models is generated for the moment magnitude ranges between 8.1 and 9.1, and regional tsunami hazard simulations are performed at the grid resolution of 270 m. The results from the stochastic tsunami simulations are characterized by evaluating the regional tsunami hazard metric that is based on the geometric mean of the maximum wave heights along the Vancouver Island coast. Subsequently, using the probability distribution of the regional tsunami hazard parameter, representative source models are identified by capturing the average as well as rare rupture cases and then detailed tsunami hazard results, such as maximum wave height maps and wave profiles at specific locations, are examined. Numerical results highlight the directivity effects of tsunami generation and wave propagation on tsunami hazards along the Canadian Pacific coast and the earthquake source characterizations in terms of fault geometry and earthquake slip distribution. The developed source models and tsunami simulation results serve as the first step for performing probabilistic tsunami hazard analysis for the Cascadia subduction zone.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47022298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-02DOI: 10.1080/21664250.2022.2122374
Borribunnangkun Kullachart, Takayuki Suzuki
ABSTRACT To better understand the physical mechanism of undertow, field observations were conducted during barred and planar beach states on the Hasaki coast in Japan. The two observation periods spanned 21 days from May 13 to June 2 in 2016, and 13 days from May 9 to May 22 in 2017, respectively. A horizontal acoustic Doppler current profiler was used to measure the undertow velocity and water level. The observed data were statistically analyzed to investigate the characteristics of the spatial and wave-energetic distributions of the undertow exceedance probability, PE . The results reveal that when the wave energy flux level was high, the undertow velocity increased, as did its PE . By contrast, the undertow PE during a low-wave-energy level decreased with greater water depths. Here, a Weibull distribution was applied to explain PE of the undertow. The Weibull parameters: scale and shape were estimated by the combination of normalized values of the wave energy flux, relative surf zone locations, and normalized water depths, and this generalized equation was considered a statistical model for estimating undertow PE . A comparison of the statistical model against the measurement demonstrates that the model accurately predicted the undertow PE with a small error.
{"title":"Statistical modeling of undertow on a natural beach","authors":"Borribunnangkun Kullachart, Takayuki Suzuki","doi":"10.1080/21664250.2022.2122374","DOIUrl":"https://doi.org/10.1080/21664250.2022.2122374","url":null,"abstract":"ABSTRACT To better understand the physical mechanism of undertow, field observations were conducted during barred and planar beach states on the Hasaki coast in Japan. The two observation periods spanned 21 days from May 13 to June 2 in 2016, and 13 days from May 9 to May 22 in 2017, respectively. A horizontal acoustic Doppler current profiler was used to measure the undertow velocity and water level. The observed data were statistically analyzed to investigate the characteristics of the spatial and wave-energetic distributions of the undertow exceedance probability, PE . The results reveal that when the wave energy flux level was high, the undertow velocity increased, as did its PE . By contrast, the undertow PE during a low-wave-energy level decreased with greater water depths. Here, a Weibull distribution was applied to explain PE of the undertow. The Weibull parameters: scale and shape were estimated by the combination of normalized values of the wave energy flux, relative surf zone locations, and normalized water depths, and this generalized equation was considered a statistical model for estimating undertow PE . A comparison of the statistical model against the measurement demonstrates that the model accurately predicted the undertow PE with a small error.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45957096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-19DOI: 10.1080/21664250.2022.2122293
M. Heidarzadeh, I. Mulia
ABSTRACT The September 2018 Palu (Sulawesi, Indonesia) tsunami has been a heavily debated event because multiple source models of three different types have been proposed for this tsunami: (i) The Mw 7.5 earthquake, (ii) landslides, and (iii) dual earthquake and landslide. Surprisingly, all of these three types of models were reported as being successful in the literature in terms of reproducing the existing tsunami observations. This can be partly attributed to the limited observations available for this tsunami. This study is motivated by the results of a marine bathymetric survey, which identified evidence for submarine landslides within the Palu Bay. Our modeling shows that the tsunami cannot be exclusively attributed to the Mw 7.5 earthquake. Inspired by the results of the marine survey, we propose a dual source model including a submarine landslide although most of the existing models include subaerial coastal landslides. Our dual model comprises an earthquake model, which has a length of 264 km, a width of 37 km, and a slip of 0–8.5 m, combined with a submarine landslide with a length of 1.0 km, a width of 2.0 km, and a thickness of 80.0 m located at 119.823°E and −0.792°S.
{"title":"A new dual earthquake and submarine landslide source model for the 28 September 2018 Palu (Sulawesi), Indonesia tsunami","authors":"M. Heidarzadeh, I. Mulia","doi":"10.1080/21664250.2022.2122293","DOIUrl":"https://doi.org/10.1080/21664250.2022.2122293","url":null,"abstract":"ABSTRACT The September 2018 Palu (Sulawesi, Indonesia) tsunami has been a heavily debated event because multiple source models of three different types have been proposed for this tsunami: (i) The Mw 7.5 earthquake, (ii) landslides, and (iii) dual earthquake and landslide. Surprisingly, all of these three types of models were reported as being successful in the literature in terms of reproducing the existing tsunami observations. This can be partly attributed to the limited observations available for this tsunami. This study is motivated by the results of a marine bathymetric survey, which identified evidence for submarine landslides within the Palu Bay. Our modeling shows that the tsunami cannot be exclusively attributed to the Mw 7.5 earthquake. Inspired by the results of the marine survey, we propose a dual source model including a submarine landslide although most of the existing models include subaerial coastal landslides. Our dual model comprises an earthquake model, which has a length of 264 km, a width of 37 km, and a slip of 0–8.5 m, combined with a submarine landslide with a length of 1.0 km, a width of 2.0 km, and a thickness of 80.0 m located at 119.823°E and −0.792°S.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43491476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-19DOI: 10.1080/21664250.2022.2124046
Nhu Y Nguyen, Duy Huy Binh Pham, Thu Thao Hoang, Van Sy Pham, Dang Dinh Kha, Tien Giang Nguyen
ABSTRACT This research aims to present a composite approach to characterizing the intra-annual and interannual variability in inlet throat width and understanding its mechanism (how, when, and why it varies). The techniques used include remote sensing imagery analysis, spectral and cross-spectral analyses, correlation analyses, and random forest variable importance. The Da Dien River mouth (DDRM), which is located in southern Central Vietnam and experiences a strong annual signal of climate regimes, was selected as a case study to demonstrate the applicability of the approach. The results show that the narrowing/widening of the DDRM throat width is highly dynamic and variable under the significant dominant influence of wave height, tide and river flow, which seasonally and interannually vary according to the monsoon regime, El Niño/Southern Oscillation and sunspot number variations (better correlation with ENSO events). The overall throat width decreases during El Niño/the positive QBO phase and increases during La Niña periods/the negative QBO phase. The difference in river flow magnitudes is the main cause for the constriction/expansion of the DDRM throat width. The successful application of the study approach to the DDRM case study demonstrates its usefulness and ability to be applied to other case studies in tropical monsoon regions.
{"title":"A composite approach towards understanding the mechanisms and driving variables of river mouth variability: A case study of the Da Dien River mouth","authors":"Nhu Y Nguyen, Duy Huy Binh Pham, Thu Thao Hoang, Van Sy Pham, Dang Dinh Kha, Tien Giang Nguyen","doi":"10.1080/21664250.2022.2124046","DOIUrl":"https://doi.org/10.1080/21664250.2022.2124046","url":null,"abstract":"ABSTRACT This research aims to present a composite approach to characterizing the intra-annual and interannual variability in inlet throat width and understanding its mechanism (how, when, and why it varies). The techniques used include remote sensing imagery analysis, spectral and cross-spectral analyses, correlation analyses, and random forest variable importance. The Da Dien River mouth (DDRM), which is located in southern Central Vietnam and experiences a strong annual signal of climate regimes, was selected as a case study to demonstrate the applicability of the approach. The results show that the narrowing/widening of the DDRM throat width is highly dynamic and variable under the significant dominant influence of wave height, tide and river flow, which seasonally and interannually vary according to the monsoon regime, El Niño/Southern Oscillation and sunspot number variations (better correlation with ENSO events). The overall throat width decreases during El Niño/the positive QBO phase and increases during La Niña periods/the negative QBO phase. The difference in river flow magnitudes is the main cause for the constriction/expansion of the DDRM throat width. The successful application of the study approach to the DDRM case study demonstrates its usefulness and ability to be applied to other case studies in tropical monsoon regions.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45396012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-13DOI: 10.1080/21664250.2022.2122300
S. Hosokawa, Shota Okura
ABSTRACT Current patterns at the mouth of Tokyo Bay have been observed since the 1970s. However, earlier studies using short-term observations and numerical analyses were too limited in their spatiotemporal scale. This study analyzed long-term observations (over a decade) obtained using an acoustic Doppler current profiler mounted on a ferry that crosses the mouth of the bay. This long-term observation dataset revealed that tidal currents dominated at the bay mouth, and that an estuarine circulation of residual current was associated with inflow into the bay along topographic pathways formed by the Tokyo Submarine Canyon and the Uraga Channel. The water volume of the inflow was substantially greater than the discharge of the four major rivers flowing into Tokyo Bay. Although the mean residual current of the surface layer on the east side was outflow, it was variable with substantial and frequent inflow from the ocean, which might have caused an oceanic environment on the east side. Analysis of the long-term observations elucidated the spatial mean picture and temporal variability of the current patterns at the mouth of Tokyo Bay. This improved knowledge and the extended dataset will help answer remaining questions regarding the water quality in Tokyo Bay.
{"title":"Long-term observation of current at the mouth of Tokyo Bay","authors":"S. Hosokawa, Shota Okura","doi":"10.1080/21664250.2022.2122300","DOIUrl":"https://doi.org/10.1080/21664250.2022.2122300","url":null,"abstract":"ABSTRACT Current patterns at the mouth of Tokyo Bay have been observed since the 1970s. However, earlier studies using short-term observations and numerical analyses were too limited in their spatiotemporal scale. This study analyzed long-term observations (over a decade) obtained using an acoustic Doppler current profiler mounted on a ferry that crosses the mouth of the bay. This long-term observation dataset revealed that tidal currents dominated at the bay mouth, and that an estuarine circulation of residual current was associated with inflow into the bay along topographic pathways formed by the Tokyo Submarine Canyon and the Uraga Channel. The water volume of the inflow was substantially greater than the discharge of the four major rivers flowing into Tokyo Bay. Although the mean residual current of the surface layer on the east side was outflow, it was variable with substantial and frequent inflow from the ocean, which might have caused an oceanic environment on the east side. Analysis of the long-term observations elucidated the spatial mean picture and temporal variability of the current patterns at the mouth of Tokyo Bay. This improved knowledge and the extended dataset will help answer remaining questions regarding the water quality in Tokyo Bay.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47981477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-04DOI: 10.1080/21664250.2022.2110657
R. Sabeti, M. Heidarzadeh
ABSTRACT In the aftermath of the deadly 2018 Anak Krakatau tsunami (Indonesia) and associated confusions over its modeling and generation mechanism, there has been an urgent need for further studies to improve our understanding of landslide-generated tsunamis. Two important factors in accurate modeling of landslide tsunamis are the wave period and the initial wave amplitude. Here, we apply a physical modeling approach and develop an empirical equation to predict the dominant wave period generated by solid-block subaerial landslide tsunamis. Fifty-one laboratory experiments are conducted at different water depths and using four different concrete blocks for the sliding masses. The results are consequently employed to derive a predictive equation for the wave period of solid-block subaerial landslide tsunamis. An innovation of this study is that we apply data from different scales (laboratory and field scales) to produce our predictive equation. For field data, the data from the 2018 Anak Krakatau event is used. We compared our predictive equation with other previously-published equations. To confirm the validity of our predictive equation, it is applied for the prediction of the wave period of an independent landslide tsunami event whose data was not used for the derivation of the equation.
{"title":"A new predictive equation for estimating wave period of subaerial solid-block landslide-generated waves","authors":"R. Sabeti, M. Heidarzadeh","doi":"10.1080/21664250.2022.2110657","DOIUrl":"https://doi.org/10.1080/21664250.2022.2110657","url":null,"abstract":"ABSTRACT In the aftermath of the deadly 2018 Anak Krakatau tsunami (Indonesia) and associated confusions over its modeling and generation mechanism, there has been an urgent need for further studies to improve our understanding of landslide-generated tsunamis. Two important factors in accurate modeling of landslide tsunamis are the wave period and the initial wave amplitude. Here, we apply a physical modeling approach and develop an empirical equation to predict the dominant wave period generated by solid-block subaerial landslide tsunamis. Fifty-one laboratory experiments are conducted at different water depths and using four different concrete blocks for the sliding masses. The results are consequently employed to derive a predictive equation for the wave period of solid-block subaerial landslide tsunamis. An innovation of this study is that we apply data from different scales (laboratory and field scales) to produce our predictive equation. For field data, the data from the 2018 Anak Krakatau event is used. We compared our predictive equation with other previously-published equations. To confirm the validity of our predictive equation, it is applied for the prediction of the wave period of an independent landslide tsunami event whose data was not used for the derivation of the equation.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48028241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-30DOI: 10.1080/21664250.2022.2117585
P. Momeni, K. Goda, M. Mokhtari, M. Heidarzadeh
ABSTRACT Tsunami hazard imposed by possible rupture of splay faults is important as it may significantly intensify tsunami heights locally. The Makran Subduction Zone (MSZ) in the northwestern Indian Ocean can generate large thrust earthquakes that could trigger significant tsunamis. In this paper, the effects of possible rupture of splay faults on the tsunami hazards of eastern MSZ are studied by developing a framework that uses stochastic earthquake rupture models and considers uncertainties related to rupture location, rupture geometry, seismic moment split ratio, earthquake slip asperity location within a fault plane, and earthquake slip heterogeneity. To quantify these uncertainties, 484 different parameter combinations of tsunami sources are considered systematically. The geometry of splay faults is developed using the most recent marine seismic surveys of the tectonic structure of the MSZ. A moment magnitude of 8.6 is considered as a scenario magnitude. The results of this study are generated in two parts, by considering average sources and stochastic sources. Results show significant local amplification of the maximum tsunami heights due to splay faults. For instance, the maximum wave height in Pasni, Pakistan can be amplified by a factor of four due to a single splay fault rupture scenario of average sources.
{"title":"A new tsunami hazard assessment for eastern Makran subduction zone by considering splay faults and applying stochastic modeling","authors":"P. Momeni, K. Goda, M. Mokhtari, M. Heidarzadeh","doi":"10.1080/21664250.2022.2117585","DOIUrl":"https://doi.org/10.1080/21664250.2022.2117585","url":null,"abstract":"ABSTRACT Tsunami hazard imposed by possible rupture of splay faults is important as it may significantly intensify tsunami heights locally. The Makran Subduction Zone (MSZ) in the northwestern Indian Ocean can generate large thrust earthquakes that could trigger significant tsunamis. In this paper, the effects of possible rupture of splay faults on the tsunami hazards of eastern MSZ are studied by developing a framework that uses stochastic earthquake rupture models and considers uncertainties related to rupture location, rupture geometry, seismic moment split ratio, earthquake slip asperity location within a fault plane, and earthquake slip heterogeneity. To quantify these uncertainties, 484 different parameter combinations of tsunami sources are considered systematically. The geometry of splay faults is developed using the most recent marine seismic surveys of the tectonic structure of the MSZ. A moment magnitude of 8.6 is considered as a scenario magnitude. The results of this study are generated in two parts, by considering average sources and stochastic sources. Results show significant local amplification of the maximum tsunami heights due to splay faults. For instance, the maximum wave height in Pasni, Pakistan can be amplified by a factor of four due to a single splay fault rupture scenario of average sources.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48729099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-17DOI: 10.1080/21664250.2022.2100179
H. Takagi, LeDuc Anh, Rezuanul Islam, Tajnova Tanha Hossain
ABSTRACT This study reviews the progress of disaster mitigation measures against tropical cyclones (TCs) in three Asian countries with different historical, social, and economic backgrounds: Bangladesh, Vietnam, and Japan. In Bangladesh, an average of 6,600 people was killed by a single TC in the 1960s, but this number had decreased to 30 in the 2010s; this reduction was due to a clear improvement in soft measures, such as weather forecasting, warning systems, and mass evacuation coordinated by volunteers. In Vietnam, several strong TCs have recently made landfall, leading to improvements in national disaster management. Although Vietnam's current disaster management budget is smaller than those of the two other countries, large-scale evacuation by local authorities is believed to have minimized casualties. In Japan, shortly after Typhoon Vera in 1959, a comprehensive law on disaster prevention was enacted, and coastal dikes were constructed nationwide, resulting in a considerable reduction in fatalities due to TCs. However, the disaster prevention facilities built in this period are now deteriorating, while Japan’s budget for disaster management is projected to be decreasing. The three countries have advanced their disaster preparedness in response to past TCs and storm surges, but new challenges have also arisen.
{"title":"Progress of disaster mitigation against tropical cyclones and storm surges: a comparative study of Bangladesh, Vietnam, and Japan","authors":"H. Takagi, LeDuc Anh, Rezuanul Islam, Tajnova Tanha Hossain","doi":"10.1080/21664250.2022.2100179","DOIUrl":"https://doi.org/10.1080/21664250.2022.2100179","url":null,"abstract":"ABSTRACT This study reviews the progress of disaster mitigation measures against tropical cyclones (TCs) in three Asian countries with different historical, social, and economic backgrounds: Bangladesh, Vietnam, and Japan. In Bangladesh, an average of 6,600 people was killed by a single TC in the 1960s, but this number had decreased to 30 in the 2010s; this reduction was due to a clear improvement in soft measures, such as weather forecasting, warning systems, and mass evacuation coordinated by volunteers. In Vietnam, several strong TCs have recently made landfall, leading to improvements in national disaster management. Although Vietnam's current disaster management budget is smaller than those of the two other countries, large-scale evacuation by local authorities is believed to have minimized casualties. In Japan, shortly after Typhoon Vera in 1959, a comprehensive law on disaster prevention was enacted, and coastal dikes were constructed nationwide, resulting in a considerable reduction in fatalities due to TCs. However, the disaster prevention facilities built in this period are now deteriorating, while Japan’s budget for disaster management is projected to be decreasing. The three countries have advanced their disaster preparedness in response to past TCs and storm surges, but new challenges have also arisen.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41260238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-14DOI: 10.1080/21664250.2022.2099683
J. Valdez, T. Shibayama, T. Takabatake, M. Esteban
ABSTRACT Haiyan in 2013 was one of the most powerful typhoons to have affected the Philippines, devastating in its path a wide portion of Leyte, and causing extensive damage to structures in Tacloban City. To understand the likely impacts that would be exerted by a storm surge on a structure deemed important, the authors used a coupled model that hindcasted the flooding that took place during Haiyan. This coupled model included the use of the Weather Research and Forecasting (WRF) Model (with Bogussing scheme) to simulate the atmospheric conditions during the passage of Haiyan, the Finite Volume Coastal Ocean Model (FVCOM) to simulate the storm surge and obtain the boundary conditions for the wind and flood (hydrostatic, hydrodynamic, and breaking wave), and the Structural Analysis and Designing Program (STAAD.Pro) to calculate the corresponding axial, shear, and bending moment envelopes based on the storm surge simulation. A 4-floor public school building in Tacloban was modeled and the effects that the storm surge would have on a corner column were analyzed. Based on the results, the axial, shear, and moment at the corner column significantly increased when considering flood loads, indicating the importance of including such loads in the design of essential structures.
{"title":"Simulated flood forces on a building due to the storm surge by Typhoon Haiyan","authors":"J. Valdez, T. Shibayama, T. Takabatake, M. Esteban","doi":"10.1080/21664250.2022.2099683","DOIUrl":"https://doi.org/10.1080/21664250.2022.2099683","url":null,"abstract":"ABSTRACT Haiyan in 2013 was one of the most powerful typhoons to have affected the Philippines, devastating in its path a wide portion of Leyte, and causing extensive damage to structures in Tacloban City. To understand the likely impacts that would be exerted by a storm surge on a structure deemed important, the authors used a coupled model that hindcasted the flooding that took place during Haiyan. This coupled model included the use of the Weather Research and Forecasting (WRF) Model (with Bogussing scheme) to simulate the atmospheric conditions during the passage of Haiyan, the Finite Volume Coastal Ocean Model (FVCOM) to simulate the storm surge and obtain the boundary conditions for the wind and flood (hydrostatic, hydrodynamic, and breaking wave), and the Structural Analysis and Designing Program (STAAD.Pro) to calculate the corresponding axial, shear, and bending moment envelopes based on the storm surge simulation. A 4-floor public school building in Tacloban was modeled and the effects that the storm surge would have on a corner column were analyzed. Based on the results, the axial, shear, and moment at the corner column significantly increased when considering flood loads, indicating the importance of including such loads in the design of essential structures.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44843537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/21664250.2022.2119011
Kangnian Wang, Yoshiyuki Nakamura, J. Sasaki, Tetsunori Inoue, Hiroto Higa, Takayuki Suzuki, Muhammad Ali Hafeez
ABSTRACT Hypoxia and blue tide are the most significant environmental issues in Tokyo Bay as they have been damaging fisheries for a long time. Although studies on modeling these two associated phenomena have been conducted for decades, the scarcity of relevant observational datasets has greatly hindered the progress, and no study has successfully reproduced the entire processes of blue tide or predicted the time and place of its outbreak. To address the problems from limited data, this study proposed a relatively conventional benthic flux model and developed a novel method that converts the total organic carbon content into the fluxes of sediment oxygen consumption and sulfide release to represent the spatial differences in benthic fluxes. A pelagic sulfur model with only three key chemical reactions of blue tide that includes the disproportionation of elemental sulfur was proposed. The method significantly improved the results of dissolved oxygen in bottom water, as seen by the root mean square error decreasing by 15.9% and 18.9% in two simulations with largely different forcings. The sulfur model also accurately predicted the outbreaks of blue tides in each simulation, which is significant to the stakeholders as it facilitates the forecast of blue tides in Tokyo Bay.
{"title":"An effective process-based modeling approach for predicting hypoxia and blue tide in Tokyo Bay","authors":"Kangnian Wang, Yoshiyuki Nakamura, J. Sasaki, Tetsunori Inoue, Hiroto Higa, Takayuki Suzuki, Muhammad Ali Hafeez","doi":"10.1080/21664250.2022.2119011","DOIUrl":"https://doi.org/10.1080/21664250.2022.2119011","url":null,"abstract":"ABSTRACT Hypoxia and blue tide are the most significant environmental issues in Tokyo Bay as they have been damaging fisheries for a long time. Although studies on modeling these two associated phenomena have been conducted for decades, the scarcity of relevant observational datasets has greatly hindered the progress, and no study has successfully reproduced the entire processes of blue tide or predicted the time and place of its outbreak. To address the problems from limited data, this study proposed a relatively conventional benthic flux model and developed a novel method that converts the total organic carbon content into the fluxes of sediment oxygen consumption and sulfide release to represent the spatial differences in benthic fluxes. A pelagic sulfur model with only three key chemical reactions of blue tide that includes the disproportionation of elemental sulfur was proposed. The method significantly improved the results of dissolved oxygen in bottom water, as seen by the root mean square error decreasing by 15.9% and 18.9% in two simulations with largely different forcings. The sulfur model also accurately predicted the outbreaks of blue tides in each simulation, which is significant to the stakeholders as it facilitates the forecast of blue tides in Tokyo Bay.","PeriodicalId":50673,"journal":{"name":"Coastal Engineering Journal","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2022-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44273936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：