• Title/Summary/Keyword: coast

Search Result 5,116, Processing Time 0.027 seconds

Determination of Design Waver along the West Coast of Korea (한국 서해안에서의 설계파의 결정)

  • 김태인;청형식
    • Water for future
    • /
    • v.20 no.2
    • /
    • pp.127-138
    • /
    • 1987
  • For determination of the design wave, a method of estimating the design wind speed at sea from the wind records at the nearby weather stations on land is proposed. Along the West Coast, the design wind speed are shown to have two main directions; namely, N through W, and WSW through S. Through the analysis of weather maps, fetches for the main wind directions along the West Coast are determined. The wind speeds at sea are found to have 0.8~0.9 times the wind speed at the stations on land for U$\geq$20m/s. The West Coast may be divided into three regions for which fetches are determind uniquely. Design waves with return period of 100 years are determined by the revised S.M..B. method along the West Coast, and show the deep water significant wave heights of 4.4~8.3 meters with wave periods of 8.9~12.0 seconds.

  • PDF

A Study on Characteristics of Coastline Change in Eastern Coast Korea (한국 동해안의 변화특성)

  • 이종태
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.15 no.1
    • /
    • pp.35-42
    • /
    • 1979
  • This paper concerns the receding of the eastern coastline of Korean peninsula at a macroscopic point of view, the result is as following. 1. Eastern coast is gradually developed from maturity stage to full maturity stage. 2. The coastline recession due to sea level rise is amounted to the receding distance, x=0.045 m per yr. 3. The author proposes another classification from the new view point, which is classified by comparing quantities between river supplying sediment loads, and the littoral drifting due to wave actions. According this, eastern coast is receding(Type Q-A), and we could find it's geomorphological characteristics. 4. The general piofile of eastern coast sand beach is erosional storm profile(Type I) which accompany offshore bar. 5. From the wave measuring data of eastern coast(Hoopo port), I can derive the linear regression line of the exceedance probability of wave height from the log-normal distribution. $z=O. 113+4.335 log_lo H, r=0.983.$ Above equation made it possible to estimate $\omega[=P(H>H_c)]for the effective wave height H_c=2. Om4, 4. Om and their corresponding values are considerable (7.8%, 0.3%) 6. Eastern coastline certainly have the tendency of erosive and receding, owing to the sea level rise, poor sediment source and effective wave actions. It's very desirable to survey coastline evolution for a long time systematically, in order to make more elaborate diagnosis.

  • PDF

A Numerical Study of Atmospheric Pollutant Dispersionon over South Korea on Sunny Summer Days (남한 지역에서 여름철 맑은 날의 대기 오염물 확산에 대한 수치적 연구)

  • 이태영;김승범
    • Journal of Environmental Science International
    • /
    • v.5 no.4
    • /
    • pp.411-427
    • /
    • 1996
  • A Lagrangian dispersion model has been developed to study the transport of atmospheric pollutants over the southern Korean peninsula on sunny summer days. A mesoscale atmospheric model has been employed to provide the wind fields and information for turbulent diffusion for the calculation of trajectories using a conditioned particle technique. The model has been applied to the simulation of the transport of atmospheric pollutants emitted from five sources in the coastal locations under various synoptic scale winds. Under calm synoptic scale condition, the particles emitted during daytime are mixed vertically and transported toward inland by sea-breeze, according to the model simulation. The particles are then transported upward at she sea-breeze front or by the upward motion over the mountain, and some particles show tendency of returning toward the coast by the return flow of the sea-breeze circulation. The particles are found to remain over the peninsula throughout the integration period under calm synoptic scale condition. When there is westerly synoptic scale winds the particles emitted in the west coast can reach the east coast within a day of faster depending on the speed. With a synoptic scale southerly wind of 5 m/s, most of the particles from the fine sources are advected toward inland during daytime. During nighttime, significant portion of particles released in the west coast remains over the land, while most particles released in the east coast move toward the sea to the east of the middle peninsula.

  • PDF

Spatio-Temporal Variation of Cold Water Masses along the Eastern Coast of Korea in 2013 and 2014

  • Han, In-Seong;Park, Myung-Hee;Min, Seung-Hwan;Kim, Ju-Yeon
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.3
    • /
    • pp.286-295
    • /
    • 2016
  • With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below $10^{\circ}C$ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below $8^{\circ}C$ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.

The Effect of Fault Failure with Time Difference on the Runup Height of East Coast of Korea (시간차를 지닌 단층파괴 활동이 동해안 처오름 높이에 미치는 영향)

  • Jung, Taehwa;Son, Sangyoung
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.4
    • /
    • pp.223-229
    • /
    • 2020
  • The fault failure process with time difference affects the initial generation of waveforms of tsunamis, which consequently changes the runup height on the coast. To examine the effect of time difference in fault failure process on the runup height, a numerical simulation was conducted assuming a number of virtual subsea earthquakes in the west coast of Japan. Results revealed that maximum runup heights along the east coast of Korea were minimal when the subfaults were aligned parallel with the shoreline. Meanwhile, if they were located perpendicular to the shoreline, the superposition effect of the initial surface by each subfault was noticeable, resulting in an increase in maximum runup height on the coast.

The Study on the Consolidation Characteristics of South Coast Spoil Reclaimed Ground by Finite Strain Consolidation Theory (유한변형률 압밀이론에 의한 남해안준설토의 압밀특성에 관한 연구)

  • Songi, Myung-Gyu;Im, Jong-Chul;Kwon, Jeong-Geun;Ju, In-Gon
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.09a
    • /
    • pp.1170-1180
    • /
    • 2009
  • Recently this country has carried out the coast reclamation centering on the west and south coast for effective practical use of a country, considering purchase of materials and environmental problem, most reclaiming work is processing to spoil reclamation which is easy to secure the amount of materials. In case of weak ground that is formed by spoil reclamation like this, initial moisture content is high, as slurry state that is rarely revealed ground strength, compressibility and water permeability have been shown nonlinear change by compaction progress. Analysis of weak ground is unreasonable because the existing Terzaghi compaction theory analyzes compaction fixed number to regular invariable number for prediction of compaction state. This study computes the relation with void ratio-effective pressure and void ratio-finite transformation which is the most basic matter to predict finite strain compaction state of the south coast spoil, and analyze the basic feature to predict compaction feature of the south coast spoil reclaimed ground.

  • PDF

Ecological Studies on the Coastal Plants in Korea -On the Sand Duen Vegetation of the Western Coast- (韓國海岸植物의 生態學的 硏究 - 西海岸의 沙丘植生에 關하여 -)

  • Lee,Woo Tchul;Sang-Keun Chon
    • The Korean Journal of Ecology
    • /
    • v.7 no.2
    • /
    • pp.74-84
    • /
    • 1983
  • The dominant species of the sand vegetation in the western coast of Korea were Carex pumila, Ischaemum antheporoides, Calystegia soldanella, Carex kobomugi and Imperata cylindrica var. koenigii. The salt content of the sand dune soil and of the atmosphere of surveyed areas ranged from 3.93 to 13.86 mg% and from 25.81 to 168.86mg% respectively. Between the salt content of the atmosphere and that of the soil positive relationship was found. Species density and Simpson's index increased with the distance from the coast, the former was exponential, however, the latter was linear. The composition of biological types in the investigated stands were H-D4-R1-3-e or H-D4-R1-3-t. Relative numbers of psammophytes and rhizome psammophytes decreased with the distance from the coast, but those of other plants increased. The standing crop of the sand dune vegetation ranged from 0.04 to 491.64g/m2 and the average 27.77g/m2. This was varied as the stands and showed a linear increment as the distance from the coast was increased. The salt content of atmosphere significantly affected the density, T/R ratio in the standing crop and Simpson's index. The salt content of soil showed similar tendency on the density and the T/R ratio.

  • PDF

A Study on the Development for the Coastal Fishing Boat attached Protected-Tunnel for Propeller (세미워터제트형 연안어선 개발에 관한 연구)

  • 고재용;심상목;박충환;서성부;배동균
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2003.05a
    • /
    • pp.16-20
    • /
    • 2003
  • Recently, The fast change of fishing boat fishery surrounding environment is connected by request of fan shape development that meet in restructuring of existing fishing boat fishery and new community, economical surrounding. In southern sea district along the coast work and district along the coast fishing bats that sail to exposed propeller fishing net, rope etc.. cold real condition that accident is increasing every year. This study is thing which analyze main performance of minuteness water jet type district along the coast fishing boat through model examination to propeller protection tunnel sticking district along the coast fishing boat that correct existing stem shape for marine accident prevention of district along the coast fishing boat in viewpoint such as ideal and examines.

  • PDF

Invasion of Foreign Barnacles into Korea Waters (외국산 따개비류의 한국내 침입)

  • 김일희
    • Animal Systematics, Evolution and Diversity
    • /
    • v.8 no.2
    • /
    • pp.163-176
    • /
    • 1992
  • Three species of foreign barnacles were found to invade into Korean interitidal seashores: Balanus amphitrite, B. ebumeus and B. improvisus. The southeastern coast of Korea, near Pusan, is the area where all the specimens of three species were discovered and the populations of these species were well establishe. B. amphitrite is the earliest invader(probably invaded around early 1970's) and most widely distributed in Korea. It is now distributed all around Korea, except the Yellow Sea coast, north of Mokpo. B. improvisus has been successful to expand its reange to the northern part of Korean coast of the East Sea, whereas B. eburneus is restricted to the southeastern coast. B. amphitrite is successfully competing with the native barnacle, B. albicostatus, and in several areas where the mixed populations of the two species occur, the latter species is found to excluded. The Yellow Sea coast has not been invaded by the foreign barnacles, the reason of which is not known.

  • PDF

The Formative Processes and Ages of Paleo-coastal Sediments in Daepo-dong Sacheon-si in the Southern Coast, South Korea: Evaluation of the Mode and Rate of the Late Quaternary Tectonism (II) (남해안 사천시 대포동 일대에 분포하는 고해안 퇴적물의 형성 과정과 형성 시기: 한반도 제4기 후기 지각운동의 양식과 변형률 산출을 위한 연구(II))

  • Shin, Jaeryul;Hong, Seongchan
    • Journal of The Geomorphological Association of Korea
    • /
    • v.25 no.3
    • /
    • pp.57-70
    • /
    • 2018
  • This study restores onshore paleo-shoreline records and establishes the nature and strain rate of neotectonism by investigating the existence and formative age of paleo-coastal sediments emerged around Sacheon-si in the Southern part of the Korean peninsula. As a result, paleo-sand bars representing 5m of the paleo-shoreline from high tide level are formed in Sacheon-si, and the formation age of these is confirmed as MIS 5c at approximately 100,000 year BP through rock surface luminescence dating to rounded gravels in paleo-sand bars. Although it is difficult to establish the uplift rate of crust precisely due to incomplete restoration of sea level records during the last interglacial stage, the uplift rate along the Southern coast of the peninsula was assumed approximately 0.72 lower than the Eastern coast during the late Quaternary in comparison to the 1st marine terrace along the Eastern coast.