• Title/Summary/Keyword: High Waves

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A Proposal for Criterion of Sudden High Waves in the East Sea (동해에서 돌연고파의 기준 제안)

  • Kim, In-Chul;Oh, Jihee;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.3
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    • pp.117-123
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    • 2016
  • One of the major characteristics of the swell-like high waves, which occur in the East Sea mostly in winter with large height and long period, is its suddenness associated with the rapid development of high waves from a calm state of sea. To represent such suddenness, in this study, the term sudden high waves is introduced. To propose the criterion of sudden high waves, comparisons were made between the wave measurement data at Gangneung and Wangdolcho for eight years from 2005 and the record of marine accidents and property damage on the coast of Gangwon-do Province and Gyeongsangbuk-do Province during the same period. It was found that most of the accidents occurred when ${\Delta}(H^2L)/{\Delta}t$ was approximately greater than the top 20% or $88.6m^3/hr$, which is therefore proposed as the criterion of sudden high waves. The used variable represents the rate of increase of the wave energy in one wavelength, including not only height and period but also suddenness of high waves.

Analysis of the Observation Data for Winter-Season High Waves Occurred in the West Sea of Korea (우리나라 서해에서 발생한 겨울철 고파의 관측자료 분석)

  • Oh, Sang-Ho;Jeong, Weon-Mu;Kim, Sang-Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.168-174
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    • 2015
  • Characteristics of high waves occurred in winter season on the west coast of Korea were investigated by analyzing the wave data observed at five observation locations. Records of four different high waves were subjected to the analysis together with the corresponding meteorological data during those time periods. The significant wave height reached its maximum of 6.42 m on December 4th, 2005. It was clarified that the high waves occurred due to strong wind fields that were formed over the west sea of Korea when the extra-tropical cyclone was excessively developed. Characteristics of the high waves generated in the west sea seemed to be predominantly wind sea as the temporal variation of the wave height at the coast were closely related to those of the wind speed measured at neighboring weather stations.

Observation of Abnormal Waves from South in Winter (겨울철에 발생한 이상 남파 관측)

  • 김태림;전기천;박광순;김상익
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.1
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    • pp.11-18
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    • 2000
  • On the 25th of November in 1997 winter season, unprecedented high waves were recorded at the southern part of Korea Peninsular. The significant wave heights over 4 m were recorded at Marado, Pusan and Ulrungdo successively with time lags. Seoguipo breakwaters which were under construction were damaged by the unexpected high waves. These unprecedented southerly high waves in winter seem to be caused by unusual development and traveling of low pressure. Weather charts and wave fields calculated by a numerical model were analyzed to examine the unusual development of these waves. Protection against the southerly high waves in winter must be considered in coastal constructions and structures.

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Abnormally High Waves on the East Coast (동해안에서의 이상 고파)

  • Jeong, Weon-Mu;Oh, Sang-Ho;Lee, Dong-Young
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.4
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    • pp.295-302
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    • 2007
  • Abnormally high waves occurring at the east coast of korea were observed at five field measurement stations and their characteristics were analyzed with the use of wind data provided by the Korean Meteorological Administration. The high waves occurred because strong Donghae twister that was developed by extratropical cyclone blew while high swell arrived at the east coast of Korea. At Sokcho, the most northern site among the five measurement stations, maximum gust speed was 63.7 m/s and significant wave height reached at its maximum of 9.69 m with the corresponding peak wave period of 12.8 s. The reason for appearance of the abnormally high waves is that high swell continued while the twister blew strongly. Moreover, the wind direction was the same as the direction of swell propagation, which maximizes the increase of wave height due to superposition of swell and wind-generated waves. On the east coast of Korea, outbreak of this type of storm waves is very probable in winter season so that it is requested to establish a countermeasure of minimizing possible damage caused by the storm waves.

Prediction of Swell-like High Waves Using Observed Data on the East Coast of Korea (관측치를 활용한 동해안 너울성 고파 예측)

  • Lee, Changhoon;Ahn, Suk Jin;Lee, Byeong Wook;Kim, Shin Woong;Kwon, Seok Jae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.3
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    • pp.149-159
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    • 2014
  • In this study, we develop an algorithm to predict swell-like high waves on the east coast of Korea using the directional wave gauge which was installed near Sokcho. Using the numerical wave model SWAN, we estimate wave data in open sea from the wave data collected by using the directional wave gauge. Then, using the wave ray method and SWAN model with the open-sea wave data as offshore boundary conditions, we predict the swell-like high waves at several major points on the east coast of Korea. We verify the prediction methods with the SWAN and wave ray methods by comparing predicted data against measured one at Wangdolcho. We can improve the prediction of the swell-like high waves in the east sea of Korea using both the real-time wave measurement system and the present prediction algorithm.

Development of Method to Predict Source Region of Swell-Like High Waves in the East Sea (동해안 너울성 고파의 발생역 추정법 개발)

  • Ahn, Suk Jin;Lee, Changhoon;Kim, Shin Woong;Jeong, Weon-Mu
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.4
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    • pp.212-221
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    • 2016
  • In this study, characteristics of swell-like high waves in the East Sea were analyzed using observed wave data and predicted meteorological data from the National Oceanic and Atmospheric Administration (NOAA). And, the wave prediction system using the data from the NOAA has been established. Furthermore, the applicability of the system has been verified by comparing the predicted results with the corresponding observed data. For some case, there were two times of wave height increase and the second increase occurred in a calm weather condition on the coast which might cause casualties. The direction of wave energy propagation was estimated from observed wave data in February, 2008. Through comparison between the direction of wave energy propagation and the meteorological data, it turns out that the second increase of waves is originated from the seas between Russia and Japan which is far from the East Sea.

Patterns of Water Level Increase by Storm Surge and High Waves on Seawall/Quay Wall during Typhoon Maemi (태풍 매미 내습시 해일$\cdot$고파랑에 의한 호안$\cdot$안벽에서의 수위증가 패턴 고찰)

  • Kang, Yoon-Koo
    • Journal of Ocean Engineering and Technology
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    • v.19 no.6 s.67
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    • pp.22-28
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    • 2005
  • We investigated the characteristics of the overflow/wave overtopping, induced by the storm surge and high waves in Masan bay and Busan Coast during Typhoon 'Maemi', which landed at the southeast coast of the Korean peninsula on September, of 2003, causing a severe inundation disaster. Characteristics of the water level, increase by the overflow / wave overtopping, were discussed in two patterns. One is the increase of water level in the region, located inside of a bay, like Masan fishing port, and the waves are relatively small. The other is in the open sea, in which the waves act directly, as on the seawall in Suyong bay. In the former region, the water level increase was affected by the storm surge, as well as the long period oscillation and waves. In Masan fishing port, about $80\%$ of the water level increase on the quay wall was caused by the storm surge. In the latter one, it was greatly affected by the wave run-up. In Suyong bay, about $90\%$ of the water level increase on the seawall was caused by the wave run-up.

Stability Evaluation of Armor Stones in the Seadike of Incoming High Waves - Focused on Saemangeum Seadike - (고파랑이 내습하는 방조제 피복석의 안정성 평가 - 새만금방조제를 중심으로 -)

  • Son, Jae Gwon;Goh, Nam Young;Kim, Duk Gu;Park, Seol Hwa
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.4
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    • pp.47-55
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    • 2016
  • This study is on the stability re-evaluation of armor stones in saemangum seadike according to recently increased sea-level and frequent high wave incoming and the results are in the following. The field inspection of armor stones in the seadike revealed that damages of armor stones have been caused by higher waves than designed waves and that the reconstruction of armor stones and concrete grouting method have been used as the reinforcement work. The result of numerical simulation of wave channel conducted to estimate the safety weight of armor stones influenced by flows revealed that the safety weight of armor stones in the seadike No.4 was estimated as 5.47 tons by using the Isbash method, which is about 122 % more than 4.49 tons estimated by using Van der Meer method. Therefore, in designing armor stones which can be influenced by high waves such as the case of Saemangum seadike, it is necessary to apply the safety weight method of armor stones, based on the Isbash method, which produced the significant figures among the safety weight methods using flows as well as the safety weight method using high waves based on the Hudson method.