• Title/Summary/Keyword: 해안 사구

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Bathymetric and Topographic Changes of the Gomso-Bay Tidal Flat, West Coast of the Korean Peninsula (한반도 서해안 곰소만 갯벌의 수심 및 지형 변화)

  • Jin Ho Chang;Yong-Gil Kim;Myong Sun Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.6
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    • pp.552-561
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    • 2023
  • The seafloor topography of Gomso Bay on the west coast of Korea was investigated using subtidal bathymetry and tidal-flat altimetry. Gomso Bay consists of 80% tidal flats and 20% subtidal zone, and is divided into an outer bay and an inner bay by the Jujincheon esturary channel. The outer bay tidal flat, has few tidal channels, has a concave topographic profile, and is characterized by the development of chenier and intertidal sand bars, giving it the appearance of gently sloping, dissipative beaches. The inner bay tidal flat has wide upper and middle tidal flats with a well-developed tidal channel system without cheniers. Moreover, the topographical cross-section between these tidal channels is convex upward, and shows the characteristics of a depositional environment greatly influenced by tidal channels and tidal action. An analysis of the horizontal movement of the tidal flat environment over the past 37 years investigating changes in the iso-depth lines in the Gomso-Bay tidal flat between 1981 and 2018 revealed that the Gomso-Bay tidal flat retreated gradually landward. As a result of analyzing the erosion and sedimentation characteristics of Gomso Bay, assuming that most of the water depth changes were due to changes in the elevation of the sea floor and sea level, an average of 1 cm (0 mm/y) of sediment was eroded in the outer bay over the past 37 years (1981-2018), In the inner bay, an average of 50 cm (14 mm/y) was deposited. Notably, the high tidal flats of the outer bay were largely eroded. Monitoring photographs of the coast showed that most of the erosion of the high tidal flats in the outer bay occurred in a short period around 1999 (probably 1997-2002), and that the erosion resulted from the erosion of sand dunes and high-tide beaches caused by temporarily greatly raised high tide levels and storms.

A Study on the Present Conditions of Conservation & Management of the Natural Monuments of Korea (국내(國內)의 천연기념물(天然記念物) 보존(保存) 관리(管理) 실태(實態))

  • Na, Moung-Ha;Lee, Jin-Hee;Lee, Jae-Keun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.2
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    • pp.127-136
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    • 2010
  • This study is aimed at reviewed and analyzed in order to suggest the improved plans related to natural monuments. The summary of this study is as followings; First, Replacing the current term 'cultural properties', which denotes the meaning of 'goods', we need to devise an new categorization that separates such properties into cultural heritage and natural heritage under the national heritage framework. Second, the designation criteria for natural monuments should be divided into the individual realm for animals and plants respectively, since they are not divided in the current Act. Third, the guidelines for naming of natural monuments should be established with the following new categories in accordance with the clear standards. Fourth, such imbalances require us to give priority to the relatively neglected types and areas. Fifth, as the big and old trees account for more than a half of the designated plants, it is necessary to search out new resources(wet plant communities, seashores, sand dune plant communities, etc.) such as geological resources, mineral springs, hot springs, and fossils that are in danger of completely being exploited and exhausted. While most of the designated animals are protected nationally, the existing designation system is required to protect habitats and breeding places for the systematic and efficient conservation. Sixth, as long as we need to preserve those historical and cultural resources for the future generations from national and global perspectives, we should enhance their values by designating them as natural monuments even though they are protected by other regulations such as the natural environment area. Seventh, as a result of the survey, we found that more budgets and experts in the local governments, more empowered organizations, more active public participation should be provided for the better Natural Monument management in Korea. Eighth, the Lap of Natural Heritage in the National Research Institute of Cultural Heritage needs to be developed to the Natural Heritage Institute to conduct the diverse activities such as researches, restoration, exhibition and education programs in a systematic and efficient way. Ninth and the last, major damages to natural monuments can be generally categorized into the artificial one and natural one, respectively. The artificial damages include toxics, soil covering, excessive humidity, fire, construction and management works, unlawful damages, fishing, oil spillage, etc, and the natural ones include lightning, storms(typhoons), heavy snowfalls, damage by insects and diseases, lack of prey, etc. This study will become meaningful in that it proposes specific measures for the improvement of the institutions, designation, and management of natural monuments on the basis of the comprehensive analysis on natural monuments. We wish to leave the other subjects related with this study to the future researches.

Characteristics of Beach Change and Sediment Transport by Field Survey in Sinji-Myeongsasimni Beach (신지명사십리 해수욕장에서 현장조사에 의한 해빈변화와 퇴적물이동 특성)

  • Jeong, Seung Myong;Park, Il Heum
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.5
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    • pp.594-604
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    • 2021
  • To evaluate the causes of beach erosion in Sinji-Myeongsasimni Beach, external forces, such as tides, tidal currents, and waves, were observed seasonally from March 2019 to March 2020, and the surface sediments were analyzed for this period. In addition, the shoreline positions and beach elevations were regularly surveyed with a VRS GPS and fixed-wing drone. From these field data, the speed of the tidal currents was noted to be insufficient, but the waves were observed to af ect the deformation of the beach. As the beach is open to the southern direction, waves of heights over 1 m were received in the S-SE direction during the spring, summer, and fall seasons. Large waves with heights over 2 m were observed during typhoons in summer and fall. Because of the absence of typhoons for the previous two years from July 2018, the beach area over datum level (DL) as of July 2018 was greater by 30,138m2 compared with that of March 2019, and the beach area as of March 2020 decreased by 61,210m2 compared with that of March 2019 because of four typhoon attacks after July 2018. The beach volume as of March 2019 decreased by 5.4% compared with that of July 2018 owing to two typhoons, and the beach volume as of September 2019 decreased by 7.3% because of two typhoons during the observation year. However, the volume recovered slightly by about 3% during fall and winter, when there were no high waves. According to the sediment transport vectors by GSTA, the sediments were weakly influxed from small streams located at the center of the beach; the movement vectors were not noticeable at the west beach site, but the westward sediment transport under the water and seaward vectors from the foreshore beach were prominently observed at the east beach site. These patterns of westward sediment vectors could be explained by the angle between the annual mean incident wave direction and beach opening direction. This angle was inclined 24° counterclockwise with the west-east direction. Therefore, the westward wave-induced currents developed strongly during the large-wave seasons. Hence, the sand content is high in the west-side beach but the east-side beach has been eroded seriously, where the pebbles are exposed and sand dune has decreased because of the lack of sand sources except for the soiled dunes. Therefore, it is proposed that efforts for creating new sediment sources, such as beach nourishment and reducing wave heights via submerged breakwaters, be undertaken for the eastside of the beach.

A Study on the Distribution of Vascular Plants around Haemyeong Mt. (Seokmodo, Incheon) and the Comparison of Invasive Alien Plants in Surrounding Forests (해명산(인천광역시 석모도) 일대의 관속식물 분포 및 주변 산림의 침입외래식물 비교에 관한 연구)

  • Lee, Jong-Won;Lee, Jin Dong;Paik, WoenKi;Yun, Ho Geun
    • Korean Journal of Plant Resources
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    • v.35 no.2
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    • pp.201-241
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    • 2022
  • This study was investigated distributed the vascular flora of around Haemyeong Mt., located in Seokmodo, Incheon, and compared invasive alien plants in the surrounding forest 14 areas. This study carried out to be established a monitoring system for the remarkable plants etc. and used as basic data for biodiversity enhancement and conservation. The survey was conducted 19 times from April 2019 to October 2020. A total of 107 families, 382 genera, 616 species, 15 sub-species, 55 varieties, 8 formas, and 694 taxa were classified in the flora around Haemyeong Mt. areas. 17 taxa for Korea endemic plants. 12 taxa were classified for rare plants, and a total of 79 taxa were identified for floristic target species I~V. Halophytes consisted of 37 taxa. The invasive alien plants were classified as 66 taxa, and also there has been 126 taxa of them in Seokmodo and surrounding 14 forests. Plants that appeared in all 14 areas out of 126 taxa were classified as 7 taxa, such as Erigeron annuus. However, 48 taxa appeared only once in some areas, but it seems inevitable that they will spread in the future. Therefore, it is necessary to prepare a long-term conservation plan for native plants.