• 제목/요약/키워드: west coast

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Evaluation of Local Erosion Characteristics of Fine-Grained Soils in the West Coast Area (서해안 세립토의 국지적 침식특성 평가)

  • Kwak, Kiseok;Lee, Juhyung;Park, Jae Hyun;Woo, Hyo Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5C
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    • pp.323-331
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    • 2006
  • It is a recent worldwide trend that erosion characteristics of soil, the resistance factor against scour, are quantified and considered in the estimation of scour depths in fine-grained soils. As part of the efforts, local erosion characteristics on fine-grained soils of the West Coast area are analyzed through scour rate experiments, where a lot of sea-crossing long-span bridges are planned and being constructed in recent years. Four sites including Incheon Bridge, Choji Bridge, Hwankyung Bridge, and Janghang area are finally selected for this study and the scour rate tests are performed using 34 undisturbed soil samples from the sites. The critical shear stresses which represent erodibility of the soil tend to be proportional to the undrained shear strength values. The relative ability of cohesive fine-grained soils to resist erosion is assumed to be higher than that of noncohesive soils. Quantified local erosion characteristics of fine-grained soils in the West Coast area are presented in forms of charts showing relationships between scour rates and shear stresses, and suggested as basic data for the estimation of scour depths and design of bridge foundations in the West Coast area.

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
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    • v.5 no.4
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    • pp.411-427
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    • 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.

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Geographical Variations of Sargassum thunbergii Morphology in Korea (한국산 갈조식물 지충이의 지리적 형태변이)

  • Kim, Sangil;Oh, Yoon Sik;Won, Nam-Il;Park, Sang Rul
    • Korean Journal of Environmental Biology
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    • v.32 no.4
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    • pp.353-362
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    • 2014
  • In this study, we investigated the effect of geographical variations on Sargassum thunbergii morphology to make a taxonomic reconsideration about infraspecific taxa in this species. In order to examine the morphological characteristics of S. thunbergii, total 27 matured and morphologically intact thalli were collected from the east, west and south coast in spring 2011. Interestingly, it was observed that the species populations on the west coast were characterized by short, thin and coarse thallus, and soft texture. However, the populations on the east coast showed thicker thallus, larger leaf and vesicle, and tougher texture. Thallus height of S. thunbergii was found to be similar at both east and west coast. Further, the height of the thallus and lateral branch of the species populations residing south coast were highest whereas the size of leaf and vesicle are shortest, in comparison with east and west coast species. Although morphological characteristics of the north east coast populations corresponded to the original description of S. thunbergii f. latifolium, we could not find exact morphological features and diagnostic characters to distinguish form in S. thunbergii. These results indicated that it is not the optimal characteristics to identify infraspecific form in this species. In contrast, morphological variations may signify the adaptation of this species to local environmental factors. Thus, we recommend that intraspecific morphological variation of S. thunbergii should be carefully used to identify infraspecific taxa.

The Characteristics of Sedimentation-Consolidation and Surface Strength for Dredging and Landfill Areas in Each Coast (해역별 준설토의 침강압밀 및 매립지 표층강도 특성)

  • Lee, Sangwoong;Gu, Bonhyo;Choi, Chaseok;Lee, Junho
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.7
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    • pp.15-22
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    • 2015
  • This study gives the characteristics of sedimentation-consolidation and surface strength for dredging and landfill areas in each coast. For the analysis of the sedimentation-consolidation characteristics, the column tests were performed and the results were compared with existing various literatures and design reports for dredged soil disposal. The surface strength of landfill soils of west and south coast were investigated by using the portable cone tester. As a results of analysis, the coefficient of sedimentation-consolidation on south coastal dredging soils is more sensitive with variation of initial water contents than on the west coastal dredging soils. And the surface strength of the dredging landfills is a higher in the west coast than in the south coast. Finally, the results of this study will be utilized as a basis data for analysis and design in the field of dredging and landfill.

A Study on the Transition Process of Fisheries Industry, Fisheries Institute of West Coast of Korea (Around the Gogunsan Islands and adjacent Area) (우리 나라 서해안(西海岸)의 수산업(水產業) 및 수산교육기관(水產敎育機關)의 변천과정(變遷過程)에 관한 사적(史的) 고찰(考察) (고군산(古群山) 군도(群島)의 인접지역(隣接地域)을 중심(中心)으로))

  • Lee, Kil-Rae
    • Journal of Fisheries and Marine Sciences Education
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    • v.11 no.1
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    • pp.24-42
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    • 1999
  • I have studied historical transition process of fisheries industries, fisheries Institute in abreast of developing fisheries industries of west coast of Korea since 1910 year with regard to the Gogunsan Is. The results were summarized as follows. In 1910 year, fishery industry has been carried out shifting fishing gear e.g set-net in shallow waters, small stow net, small seine net adapting to the tophorgrapical feature, shape of coast, oceanic condition, however, the fishing gear and fishing method were undeveloped, so that, Japanese fishermen had been exploited fisheries resources penetrating the fishing ground. Most important species were lot of captured croaker, cod, spanish mackeral, sea abream, herring in coastal sea. nowaday, squid, anchovy, shrimp, crab, pompret were much captured. The species were captured in 18 century were not captured. It is rarely than that period. Fishereis aquatic culture had been not farmed till 1960 year, but sea laver, shrimp, crab, had been breeded 1970 year also, the fresh water fish e.g. eel, cat-fish had been breeded activately. The fisheries processing industry were composed of salt. icing, dry, method. the salted fish industry had been prevailed at Gangyng, Kwangchon, Kunsan, Julpo comparatively. The fisheries institute had been established at Kunsan at first, but institute established in other region had been abolished in a short time. This phenomenon was related with development of fisheries resources. The western coast fisheries industries had been wasted of decreasing of fisheries resources, variation of environment. Accordingly, the study of preserving the marine resources. educated man power who engaged in fisheries field have to accomplish. Sea was dying with reason of loss of mud in west coast factory waste, waste of life the increase of accident of sea polluted, each illegal fishing industry physical and chemical reason etc. in this respect, Kusan maritime college, fisheries developing agency, institute have to take important role for developing fishing industry.

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A Study on the Status of Waterbirds by Taxon and Seasonal Arrival in the South-West Coast Islands

  • Hyun-Young Park;Sun-Jib Kim
    • International Journal of Advanced Culture Technology
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    • v.11 no.1
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    • pp.349-355
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    • 2023
  • This study surveyed the island located in Sinan-gun and Wando-gun four times, once per season from September 2020 to November 2021 in order to understand the distribution of waterbirds on the island of the southwest coast. As a result of the investigation, a total of waterbirds of 7 orders, 12 families of 50 species, and 3,680 individuals were identified. By taxon, the largest number of species were identified as 11 species of waders, and the number of ducks was the largest with 2,035 individuals. In Bigeum-do Island, where forests are distributed less, the proportion of farmland is large, and tidal flats are widely distributed, the largest number of species and individuals of herons and waders were identified. Ducks and gulls have also been identified in large numbers of individuals in Bigeum-do Island. Most of them are forests and farmland, and the largest number of species and individuals of ducks have been identified in Pyeongil-do Island, where the coast is deep. In addition, Nodae-do Island, Sobyeongpung-do, and Daebyeongpung-do Island with monotonous habitats have been identified with fewer species and individuals. As a result, We learned that various types of waterbirds lived in islands with various habitats, and that the preferred habitat was different depending on the characteristics of the taxon group. By season, the largest number of species was identified as 35 in autumn, and the largest number of individuals was identified as 1,681 in winter. Although most of the seasonally identified waterbirds were winter birds, the largest number of species were identified in autumn, and most of the confirmed waterbird migration were identified in the autumn, indicating that waterbirds used the west-south coast islands as an intermediate stopover while traveling.

Meteorological Mechanisms Associated with Long-range Transport of Asian Dust Observed at the West Coast of North America in April 2001

  • Song Sang-Keun;Kim Yoo-Keun;Moon Yun-Seob
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.E1
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    • pp.1-14
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    • 2004
  • Meteorological mechanisms in association with long-range transport of Asian dust in April 2001 have been investigated using weather maps, satellite images, TOMS and surface $PM_{10}$ data, backward trajectories, plus modeling output results (geopotential heights, horizontal wind vectors, potential temperatures, and streamlines). The results indicated that long -range transport of Asian dust to the west coast of North America was associated with strong westerlies between the Aleutian low and the Pacific high acting as a conveyor belt. Accelerating westerly flows due to cyclogenesis at the source regions over East Asia transported pollution from the continent to the central Pacific. When the system reached the Aleutian Islands, the intensity of troughs and the westerlies were amplified in the North Pacific. Thereafter the winds between the Aleutian Islands and the Pacific Ocean were more intensified from the air flow transport of the conveyor belt. Consequently, the strong wind in the conveyor belt enhanced the dust transport from the Pacific Ocean to the west coast of North America. This was evidenced by $PM_{10}$ concentration (maximum of about $100{\mu}g\;m^{-3}$) observed In California. Further evidence of the dust transport was found through the observation of satellite images, the distribution of TOMS aerosol index, and the analyses of streamlines and backward trajectories.

Storm Surges in West Coast of Korea by Typhoon Bolaven (1215) (태풍 볼라벤 (1215)의 서해안 폭풍해일 분석)

  • Seo, Seung Nam;Kim, Sang Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.1
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    • pp.41-48
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    • 2014
  • To analyze the surface elevation data of Typhoon Bolaven, simple analytical models are employed to investigate major causes of the storm surges in the west coast of Korea. Although the simple models cannot reproduce the storm surges by Typhoon Bolaven accurately, they are able to provide sufficient evidence of physical processes involved in the storm surges. Surges in islands located at deeper water were mainly driven by typhoon low pressure rather than associated winds. In contrast, bigger storm surge heights more than 1m were recorded in shallow coastal areas during low tide, which were dominantly produced by typhoon winds.

Flooded Analysis for Multi-Utilization of Reclaimed Tidelands in the West Coast District (서해안지역 간척농지의 다각적 활용을 위한 침수안전지역 설정 연구)

  • Park, Myeong Soo;Yun, Dong Koun;Han, Guk Heon;Oh, Sung Tae;La, Min Chul
    • KCID journal
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    • v.19 no.1
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    • pp.50-63
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    • 2012
  • Many reclaimed tideland projects in Korea have been conducted to secure the food self-sufficiency. In fact, the domestic food self-sufficiency has been greatly improved and reclaimed tideland projects contribute to Korea's economic and social development directly or indirectly replacing agricultural lands from urbanization, industrialization. As result, current self-sufficiency of rice reach the demand(104.6%) while rate of upland crops has less than 30% of self-sufficiency rate and corn, wheat, soybeans, etc. are virtually dependent on imports. Domestic price of crop is expected to be unstable by trend of international grain prices. Therefore, developing reclaimed tidelands as upland which is originally constructed for paddy fields could be a good option to become steady in domestic crop market and dedicate to ensure a stable food security. The study to prepare measures for dealing with disasters in reclaimed tidelands of west coast district is required in order to utilize those sites for infra construction of multi-utilization in those sites and The result of flooding analysis in this study can suggest policy direction for practical utilization of reclaimed tidelands in yellow sea area.

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An Analysis on the change in Topography in the West Coast Using Landsat Image (Landsat 영상을 이용한 서해안 지형 변화 추이 분석)

  • 강준묵;윤희천;강영미
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.11a
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    • pp.275-279
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    • 2004
  • This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using the images from the satellite, which were given the geometric correction based on the GCP (Ground Control Point) and DEM (Digital Elenation Model) data. The accuracy of the images was examined by .empaling them with CCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From this study, the accuracy of the images of the west coast from satellite could be acquired and the change of the topology and terrain was detected effectively. From the results, it was known that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land. In Sihwa, the size of the land was increased 180 $\textrm{km}^2$ and that of the seashore was decreased 110 km. in Hwaong the size was increased 50 $\textrm{km}^2$ and in Ansan the city space was increased 71 $\textrm{km}^2$ due to the formation of the industrial complex.

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