scholarly journals Hazard Assessment of Typhoon-Driven Storm Waves in the Nearshore Waters of Taiwan

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 926 ◽  
Author(s):  
Chih-Hsin Chang ◽  
Hung-Ju Shih ◽  
Wei-Bo Chen ◽  
Wen-Ray Su ◽  
Lee-Yaw Lin ◽  
...  
Keyword(s):  
Human Life ◽  
Coupled Model ◽  
Storm Surges ◽  
Coastal Zones ◽  
Wind Fields ◽  
Storm Waves ◽  
Storm Wave ◽  
Wave Heights ◽  
Hazard Level ◽  
Hazard Levels

In Taiwan, the coastal hazard from typhoon-induced storm waves poses a greater threat to human life and infrastructure than storm surges. Therefore, there has been increased interest in assessing the storm wave hazard levels for the nearshore waters of Taiwan. This study hindcasted the significant wave heights (SWHs) of 124 historical typhoon events from 1978 to 2017 using a fully coupled model and hybrid wind fields (a combination of the parametric typhoon model and reanalysis products). The maximum SWHs of each typhoon category were extracted to create individual storm wave hazard maps for the sea areas of the coastal zones (SACZs) in Taiwan. Each map was classified into five hazard levels (I to V) and used to generate a comprehensive storm wave hazard map. The results demonstrate that the northern and eastern nearshore waters of Taiwan are threatened by a hazard level IV (SWHs ranging from 9.0 to 12.0 m) over a SACZ of 510.0 km2 and a hazard level V (SWHs exceeding 12.0 m) over a SACZ of 2152.3 km2. The SACZs threatened by hazard levels I (SWHs less than 3.0 m), II (SWHs ranging from 3.0 to 6.0 m), and III (SWHs ranging from 6.0–9.0 m) are of 1045.2 km2, 1793.9 km2, and 616.1 km2, respectively, and are located in the western waters of Taiwan.

scholarly journals Storm wave modeling with swan comparison of measurement data and modeling results for the storm MUIFA 11/2004

2005 ◽  
Vol 27 (4) ◽  
pp. 229-239 ◽  
Author(s):  
Nguyen Manh Hung ◽  
Do Le Thuy ◽  
Duong Cong Dien
Keyword(s):  
Weather Forecasting ◽  
Human Life ◽  
Measurement Data ◽  
Weather Forecast ◽  
Coastal Zones ◽  
Red River Delta ◽  
Coastal Evolution ◽  
Storm Waves ◽  
Storm Wave ◽  
Wave Forecasting

With the average of 4-5 storms hitting the Vietnamese coastline every year, our country is suffering from great damage of infrastructures and lost of human life. Most storms induce significant waves which, especially in the coastal zones, can destroy houses, coastal structures and move large amounts of sand from beaches to offshore resulting in shoreline erosion. Therefore modeling of storm waves is an important task of engineers, scientists, weather forecasting specialists of our country. In order to meet the need of mitigation storm effects, to improve the storm wave forecasting capability in general and to study the coastal evolution in the Red River Delta (RRD) in particular, the authors have developed the S\i\TAN model for the storm wave calculation in the East Sea. In the paper some formulations of the model has been used to get the best agreement with the measured wave field in the storm MUIFA 11 /2004. The wind and wave data at the oil platform MSPl and wave height field over the sea were used to compare the model results. The obtained results afford the promising of using the SWAN model in research and weather forecast.

scholarly journals A COMPARISON OF NATURE WAVES AND MODEL WAVES WITH SPECIAL REFERENCE TO WAVE GROUPING

1980 ◽  
Vol 1 (17) ◽  
pp. 177 ◽  
Author(s):  
Hans F. Burcharth
Keyword(s):  
Phase Distribution ◽  
Random Phase ◽  
Power Spectra ◽  
Height Distribution ◽  
Wave Group ◽  
Storm Waves ◽  
Wave Height Distribution ◽  
Storm Wave ◽  
Wave Heights ◽  
The Impact

This paper represents a comparative analysis of the occurrence of wave grouping in field storm waves and laboratory waves with similar power spectra and wave height distribution. Two wave patterns - runs of waves and jumps in wave heights - which have significant influence on the impact on coastal structures were included in the analysis of storm wave records off the coasts of Cornwall, U.K. and Jutland, Denmark. Two different laboratory wave generator systems, based on random phase distribution of component waves, were used. Within the limitations given by the relatively small number of analysed records it is shown that wave group statistics can be satisfactorily reproduced by random phase generators that are not based on a limited number of component waves, but for example based on filtering of white noise. It is also shown that the statistics of large waves and wave groups containing large waves depend on whether the waves are defined from zero-upcrossings or zero-downcrossings. Although very similar seas were chosen for the analysis it was found that significant differences in the wave group statistics from the two locations existed. Also a considerable scatter in the wave group statistics throughout the storms was found.

scholarly journals Evaluation of landslide hazard level on spatial pattern of Tanah Datar Regency

2018 ◽  
Vol 229 ◽  
pp. 03006
Author(s):  
Indang Dewata ◽  
Iswandi Umar
Keyword(s):  
Land Use ◽  
Spatial Pattern ◽  
Human Life ◽  
Landslide Hazard ◽  
Residential Areas ◽  
Scoring Method ◽  
High Hazard ◽  
Hazard Level ◽  
Moderate Hazard ◽  
Hazard Levels

Natural disasters have caused much harm to human life. Migration through disaster based planning is one way to minimize risks. The purpose of this study is to evaluate the level of landslide hazard in the planning of spatial pattern in Tanah Datar Regency. To determine the landslide hazard level using the scoring method through the overlay of a thematic map. Indicators used are slope, rainfall, soil type, geology, landform, and land use. Furthermore, evaluation of landslide hazard on spatial planning is determined by overlaying hazard level maps with land use plans in spatial pattern planning. The results showed that the 26% landslide hazard rate was a high danger level, 46% moderate hazard level, and 38% low hazard level. In addition, hazard level evaluation of spatial patterns resulted in approximately 37.3% planning for residential areas having high hazard levels. Therefore, it is necessary to revise the pattern of regional space and include the element of disaster in the planning of spatial pattern.

scholarly journals Effect of Tides and Storm Surges on Storm Waves at the Northern Coastal Areas of Vietnam

2019 ◽  
Vol 35 (2) ◽  
Author(s):  
Nguyen Ba Thuy
Keyword(s):  
Storm Surge ◽  
Wave Height ◽  
Operating Time ◽  
Storm Surges ◽  
Wave Radiation ◽  
Observation Data ◽  
Ocean Engineering ◽  
Super Typhoon ◽  
Storm Waves ◽  
Storm Wave

Abstract: In this study, the effect of tides and storm surges on storm waves at the Northern coastal area of Vietnam is investigated by a coupled model of surge wave and tide (called: SuWAT). In particular, tide and storm surge are simulated by two-dimensional long wave equations taking into account the wave radiation stress, obtained from the SWAN model. The numerical was then applied to simulate storm waves and surges for typhoon Frankie (7/1996), Washi (7/2005) and Doksuri (9/2017). In the case of the super typhoon, the intensity of typhoon Washi is increased to level 16 (super typhoon level) but remains the same trajectory and operating time. The numerical results showed relatively well with observation data on storm surge and wave height. In general, the wave height is higher in the region near the coast and lower at offshore when considering the effect of tide and storm surge on storm wave. It also indicated that the effect of storm surge on storm wave is more significant than the tide. The results of the study are the basis for proposing to improve the wave forecasting technology in the study area. Keywords: Storm wave, tides, storm surge, super typhoon. References: [1] Đ. Đ. Chiến, N. B. Thủy, N.T. Sáo, T.H. Thái, S. Kim. Nghiên cứu tương tác sóng và nước dâng do bão bằng mô hình số trị, Tạp chí Khí tượng Thủy văn, 647 (2014) 19-24.[2] T.Q. Tiến, P.K. Ngọc. Kết nối mô hình SWAN với mô hình WAM thành hệ thống dự báo sóng biển cho vùng Vịnh Bắc Bộ, Tạp chí Khí tượng Thủy văn, 651 (2014) 21-26.[3] Y.Funakoshi, S.C.Hagen, P.Bacopoulos. Coupling of hydrodynamic and wave models: case study for Hurricane Floyd (1999) Hindcast, Journal of Waterway, Port, Coastal and Ocean Engineering, 134 (2008) 321 – 335.[4] S.Y. Kim, T. Yasuda, H. Mase. Wave set-up in the storm surge along open coasts during Typhoon Anita, Coastal Engineering, 57 (2010) 631-642.[5] X. Bertin, K. Li, A. Roland, and J.R. Bidlot. The contribution of short waves in storm surges: two recent examples in the central part of the bay of Biscay, Continental Shelf Research 96 (2015) 1-15.[6] H.Đ. Cường, N.B. Thủy, N.V. Hưởng, D.Đ. Tiến. Đánh giá nguy cơ bão và nước dâng do bão tại ven biển Việt Nam, Tạp chí khí tượng thủy văn, 684 (2018) 29-36.[7] Delf University of Technology. SWAN Cycle III Verion 40.31, User Guide. Delf, 2004.[8] N.B. Thủy, H.Đ. Cường, D.Đ. Tiến, Đ.Đ. Chiến, S.Kim. Đánh giá diễn biến nước biển dâng do bão số 3 năm 2014 và vấn đề dự báo, Tạp chí Khí tượng Thủy văn, 647 (2014).14-18.[9] N.B. Thuy, S. Kim, D.D. Chien, V.H. Dang, H.D. Cuong, C. Wettre and L. R. Hole. Assessment of Storm Surge along the Coast of Central Vietnam, Coastal researcher Journal, 33 (2017) 518-530.[10] V.H. Đăng, N.B. Thủy, Đ.Đ. Chiến, S. Kim. Nghiên cứu đánh giá định lượng các thành phần nước dâng trong bão bằng mô hình số trị, Tạp chí khoa học công nghệ biển. 17 (2017) 132-138.[11] T. Fujita. Pressure distribution within typhoon, Geophysical Magazine, 23 (1952). 437-451.

scholarly journals THE DESIGN CONCEPT OF DUAL BREAKWATERS AND ITS APPLICATION TO TOWNSVILLE, AUSTRALIA

1980 ◽  
Vol 1 (17) ◽  
pp. 115 ◽  
Author(s):  
W. Bremner ◽  
D.N. Foster ◽  
C.A. Miller ◽  
B.C. Wallace
Keyword(s):  
Wind Band ◽  
Cost Savings ◽  
Storm Surges ◽  
Time Interval ◽  
Strong Wind ◽  
Storm Waves ◽  
Weather Events ◽  
Long Time ◽  
Wave Heights ◽  
Strong Winds

In Central and North Queensland the coastline is protected by the Great Barrier Reef over a length of some 1900km from Gladstone in the south to the tip of Cape York (Fig. 1). The fetch distance from the reef to the coastline is very variable from about 15km to 140km. Hence the coastal areas north of Gladstone have moderate to low wave climates except during abnormal weather events such as cyclones or long time interval bands of strong winds. In these events larger storm waves of significant wave heights of 10m may be superimposed, in the case of cyclones, on storm surges several metres in height. The design of breakwaters and shoreline structures for protection against all except cyclonic and strong wind band effects requires, in the main, readily available sizes of armour rock and relatively low crest elevations. To offer similar protection against cyclonic weather events often requires the use of artificial armour units of concrete and a substantial increase in crest heights. The resulting increase in costs makes many of the small projects uneconomic. In this paper the concept of using an offshore breakwater which is designed to fail under extreme wave conditions to protect an inner breakwater or revetment is examined and the results applied to Townsville Harbour where cost savings of the order of 40 percent were achieved over a conventional design.

Hindcasting Hurricane Waves in the Gulf of Mexico

1972 ◽  
Vol 12 (04) ◽  
pp. 321-328 ◽  
Author(s):  
M. M. Patterson
Keyword(s):  
Gulf Of Mexico ◽  
Wave Height ◽  
Wind Field ◽  
Design Theory ◽  
Time History ◽  
Wind Fields ◽  
Platform Design ◽  
Synoptic Wind ◽  
Storm Wave ◽  
Wave Heights

Abstract An estimate of wave heights is needed for risk and venture analysis, for platform design, and for operational planning. Very little reliable data on hurricane waves have been available for a number of years. The present hindcast system uses a moving, two-dimensional wind field to generates and propagate waves to a location of interest. The propagate waves to a location of interest. The wind-wave model is based on work reported in the literature by Wilson. Wave Program I uses a synoptic wind field based on measurements or observations. Wave Program II generates its own wind field based on the track, the time history of the radius to maximum Winds, and the barometric pressure of the storm. Wave Program III also pressure of the storm. Wave Program III also generates its own wind fields, but the storm is moved along a predetermined path. The results of all three hindcast methods have been compared with data gathered from Hurricane Carla. Other hurricanes have also been studied and each of the programs gives comparable results. programs gives comparable results Introduction The most critical environmental factor in deepwater platform design is the selection of wave heights to which the platform will be subjected. Regardless of the design theory, wave loading contributes a major portion of the environmental force on a deep-water platform. To date there has been little sound historical evidence of the magnitude of wave heights that could occur in the Gulf of Mexico. To overcome this problem the offshore oil industry has sought an answer by two related methods. The first method consists of several measuring programs to gather both wave force and wave height information. Since reliable measuring techniques have existed for only a short time, the second method consists of developing techniques to predict historical waves that probably occurred in the Gulf of Mexico. The purpose of this paper is to document Shell's efforts in hindcasting paper is to document Shell's efforts in hindcasting waves for hurricanes that have passed through the Gulf since 1900. In order to hindcast waves, it was necessary to find a mathematical simulation model that would generate waves from a moving wind field. Such wind fields may be taken from synoptic charts or developed from empirical equations based on hurricane data such as radius to maximum winds, central pressure, and forward speed. WAVES FROM A MOVING WIND FIELDTHE BASIC WILSON MODEL Wilson, a consultant in the field of oceanography, has developed a mathematical model that would generate and propagate waves based on a moving wind field. We shall discuss the basic equations for this technique, but shall not go into detail concerning how the equations were developed. INITIATION OF THE WAVE The first wave height generated by a moving wind field can be calculated from Eq. 1 below (1) H1 = 0 .0636U In the above equation Ui is the wind vector in the direction of propagation at time zero and location (x1) where the wave is to start. The distance x1 over which the wave will move is described in Eq. 2. (2) =  0 .761 x1 is the distance the wave travels in nautical miles before it is to be modified by another value of wind velocity. The celerity is defined by Eq. 3. (3) C1  =  2 .498 Finally, the period and wave length of this initial wave are described below. (4) T1  =  C1/3 (5)1 2L1  =  5 .12T SPEJ P. 321

scholarly journals Assessing the Potential Highest Storm Tide Hazard in Taiwan Based on 40-Year Historical Typhoon Surge Hindcasting

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 346 ◽  
Author(s):  
Yi-Chiang Yu ◽  
Hongey Chen ◽  
Hung-Ju Shih ◽  
Chih-Hsin Chang ◽  
Shih-Chun Hsiao ◽  
...  
Keyword(s):  
Coupled Model ◽  
Storm Surges ◽  
Storm Tide ◽  
Astronomical Tide ◽  
Individual Potential ◽  
Hazard Level ◽  
The Individual ◽  
Central Weather Bureau ◽  
Fully Coupled

Typhoon-induced storm surges are catastrophic disasters in coastal areas worldwide, although typhoon surges are not extremely high in Taiwan. However, the rising water level around an estuary could be a block that obstructs the flow of water away from the estuary and indirectly forms an overflow in the middle or lower reaches of a river if the occurrence of the highest storm surge (HSS) coincides with the highest astronomical tide (HAT). Therefore, assessing the highest storm tide (HST, a combination of the HSS and HAT) hazard level along the coast of Taiwan is particularly important to an early warning of riverine inundation. This study hindcasted the storm surges of 122 historical typhoon events from 1979 to 2018 using a high-resolution, unstructured-grid, surge-wave fully coupled model and a hybrid typhoon wind model. The long-term recording measurements at 28 tide-measuring stations around Taiwan were used to analyze the HAT characteristics. The hindcasted HSSs of each typhoon category (the Central Weather Bureau of Taiwan classified typhoon events into nine categories according to the typhoon’s track) were extracted and superposed on the HATs to produce the individual potential HST hazard maps. Each map was classified into six hazard levels (I to VI). Finally, a comprehensive potential HST hazard map was created based on the superposition of the HSSs from 122 typhoon events and HATs.

scholarly journals Intermittent but Rapid Changes to Coastal Landscapes: The Tsunami and El Niño Wave-Formed Sea Arch at Laie Point, Oahu, Hawaii, U.S.A.

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 147
Author(s):  
Benjamin R. Jordan
Keyword(s):  
El Niño ◽  
El Nino ◽  
Sand Dunes ◽  
Tsunami Source ◽  
Tsunami Waves ◽  
Storm Waves ◽  
The Pacific ◽  
Coastal Landscapes ◽  
Wave Heights ◽  
First Time

Kukuiho’olua Island is an islet that lies 164 m due north of Laie Point, a peninsula of cemented, coastal, Pleistocene and Holocene sand dunes. Kukuiho’olua Island consists of the same dune deposits as Laie Point and is cut by a sea arch, which, documented here for first time, may have formed during the 1 April 1946 “April Fools’s Day Tsunami.” The tsunami-source of formation is supported by previous modeling by other authors, which indicated that the geometry of overhanging sea cliffs can greatly strengthen and focus the force of tsunami waves. Additional changes occurred to the island and arch during the 2015–2016 El Niño event, which was one of the strongest on record. During the event, anomalous wave heights and reversed wind directions occurred across the Pacific. On the night of 24–25 February 2016, large storm waves, resulting from the unique El Niño conditions washed out a large boulder that had lain within the arch since its initial formation, significantly increasing the open area beneath the arch. Large waves also rose high enough for seawater to flow over the peninsula at Laie Point, causing significant erosion of its upper surface. These changes at Laie Point and Kukuio’olua Island serve as examples of long-term, intermittent change to a coastline—changes that, although infrequent, can occur quickly and dramatically, potentially making them geologic hazards.

Methodology for seismic risk assessment for tubular steel wind turbine towers: application to Canadian seismic environment

2011 ◽  
Vol 38 (3) ◽  
pp. 293-304 ◽  
Author(s):  
Elena Nuta ◽  
Constantin Christopoulos ◽  
Jeffrey A. Packer
Keyword(s):  
Seismic Hazard ◽  
Wind Turbine ◽  
Seismic Loading ◽  
Element Analysis ◽  
Design Spectrum ◽  
Wind Turbine Tower ◽  
Damage States ◽  
Wind Turbine Towers ◽  
Hazard Level ◽  
Hazard Levels

The seismic response of tubular steel wind turbine towers is of significant concern as they are increasingly being installed in seismic areas and design codes do not clearly address this aspect of design. The seismic hazard is hence assessed for the Canadian seismic environment using implicit finite element analysis and incremental dynamic analysis of a 1.65 MW wind turbine tower. Its behaviour under seismic excitation is evaluated, damage states are defined, and a framework is developed for determining the probability of damage of the tower at varying seismic hazard levels. Results of the implementation of this framework in two Canadian locations are presented herein, where the risk was found to be low for the seismic hazard level prescribed for buildings. However, the design of wind turbine towers is subject to change, and the design spectrum is highly uncertain. Thus, a methodology is outlined to thoroughly investigate the probability of reaching predetermined damage states under any seismic loading conditions for future considerations.

scholarly journals Effectiveness of low-impact development for urban inundation risk mitigation under different scenarios: a case study in Shenzhen, China

2018 ◽  
Vol 18 (9) ◽  
pp. 2525-2536 ◽  
Author(s):  
Jiansheng Wu ◽  
Rui Yang ◽  
Jing Song
Keyword(s):  
Local Governments ◽  
Risk Mitigation ◽  
Low Impact Development ◽  
Green Roofs ◽  
Rapid Urbanization ◽  
Storm Water Management Model ◽  
Inundation Depth ◽  
High Hazard ◽  
Hazard Level ◽  
Hazard Levels

Abstract. The increase in impervious surfaces associated with rapid urbanization is one of the main causes of urban inundation. Low-impact development (LID) practices have been studied for mitigation of urban inundation. This study used a hydrodynamic inundation model, coupling SWMM (Storm Water Management Model) and IFMS-Urban (Integrated Flood Modelling System–Urban), to assess the effectiveness of LID under different scenarios and at different hazard levels. The results showed that LID practices can effectively reduce urban inundation. The maximum inundation depth was reduced by 3 %–29 %, average inundation areas were reduced by 7 %–55 %, and average inundation time was reduced by 0 %–43 % under the eight scenarios. The effectiveness of LID practices differed for the three hazard levels, with better mitigation of urban inundation at a low hazard level than at a high hazard level. Permeable pavement (PP) mitigated urban inundation better than green roofs (GRs) under the different scenarios and at different hazard levels. We found that more implementation area with LID was not necessarily more efficient, and the scenario of 10 % PP+10 % GR was more efficient for the study area than other scenarios. The results of this study can be used by local governments to provide suggestions for urban inundation control, disaster reduction, and urban renewal.

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