• Title/Summary/Keyword: mud flat

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An Analysis of Micro-landform and Its Grain Size of Tidal Flat in Gomso-Bay using Satellite Remote Sensing (위성원격탐사를 이용한 곰소만 간석지의 미지형과 퇴적물 입도특성 분석)

  • Jo, Wha-Rhong;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.1
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    • pp.44-56
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    • 2000
  • Through the ISODATA method of unsupervised classification, the micro-landform of Gomso-Bay tidal flat was classified into mud, mixed, and sand flats by using Landsat TM image. Each tidal flat shows on apparent differences in its topographical characteristics and grain size compositions. Mud flat is occupied the innermost part of the tidal flat. Sand flat is distributed adjacent to the entrance of the bay, while the mixed one is located in the central part of the bay. Mud flat deposits have fine grain size, more than 4 in average mean phi, bad sorting, more than 1 phi in standard devation, and positive skewness. Mixed and sand flat deposits have coarse grain size, less than 4 average mean phi, good sorting, less than 1 phi in standard daviation, and negative skewness. Topographically, the mud flat consists of flat surfaces and dissected channels. The average depth of dissected channels is about 2 meters. Meanwhile, sand flat has a very flat landform with well-developed ripple marks of less than 10 centimeters in average relief. And the mixed one shows the intermediate topographical characteristics of those of mud and sand flats.

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A Establishment of Mud Flat Restoration Plan in Gochang Using Abandoned Embanked Farms (축제식(築堤式) 폐양식장을 활용한 고창 갯벌 복원계획 수립)

  • Choi, Hee-Sun;Kim, Hyo-Chang
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.2
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    • pp.124-137
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    • 2010
  • This study was started with the objective of restoring abandoned embanked farms, which are recently increasing, to mud flat by putting in least amount of energy in the aspect of environmental restoration. For the direction and establishment of the proposal for the restoration of mud flat using embanked farms, a case of Maipo Wetland in Hongkong was analyzed, and a proposal was prepared considering the condition of mud flat in Gochang. The restoration of mud flat in Gochang is intended to create various wetland ecological spaces as well as to provide opportunities for experience, education, recreation, and tourism. Effort was made to development an environment closest to the local ecological environment considering the shape and topographical condition of existing abandoned farms. For construction of the habitat, a target species was chosen and the plan for selection, planting, and management of species of trees suitable for the target species was established. In addition, the water level will be controlled by water gates to conform to the resting, spawning, breeding, and migration period considering the behavioral pattern of waders, the target species. The research on the restoration of mud flat in Korea is in incipient stage and this study provided an opportunity to review the possibility of restoration of abandoned embanked farms to mud flat. For the success of mud flat restoration from a long-term perspective, development of acclimating design infrastructure, technology improvement for mud flat restoration, and basis of partnership for the maintenance should be prepared in a systematical way.

Characteristic of mixing rate of mud flat on Mortar in W/C 70% (W/C 70%인 모르타르에서의 갯벌 혼입률에 따른 특성)

  • Lee, Heung-Yeol;An, So-hyun;Yang, Seong-Hwan
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.30-31
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    • 2016
  • Recently in the construction site is required various performance of mortar to deal with reliability, economy. Especially of environment-friendly, saving resources and high performance of mortar it began to require improvement of performance. Therefore, in this study, a series of tests was designed to develop a using mud flat mortar in view of the high absorption rate of tidal flats, to fix the water cement ratio to 70%. The mixing ratio were 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6 of fine aggregate and mud flats. Compared the flow value, chloride content, compressive strength, tensile strength, and workability of fine aggregate the substituted mud flat mortar and basic cement mortar, present the basic data on the characteristics and effects of mud flat mortar.

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Sedimentological Properties Of the Recent Intertidal Flat Environment, Southern Nam Yang Bay, West Coast Of Korea (남양만 남부 조간대 퇴적환경의 퇴적학적 특성에 관하여)

  • Chung, Gong Soo;Park, Yong Ahn
    • 한국해양학회지
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    • v.13 no.1
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    • pp.9-18
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    • 1978
  • The intertidal flat depositional environment of Southern Nam Yang Bay, west coast of Korea has been studied to understand textural, geochemical and mineralogical characteristics. The intertidal flat environment can be divided into two subenvironments, that is, the mud flat and the sand flat due to the sediment textures. From thd outer sand flat to the inner mud flat the grain size of the sediments decreases and the mud content increases. It is suggested that the intertidal flat environment is in the progradation of marsh deposits in the mud flat. The chemical composition of the sediments is related to the sediment textures. The chemical index of maturity of the mud flat sediments is higher than that of the sand flat sediments. The clay minerals of the sediments are chlorite, illite, montmorillonite and kaolinite.

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Comparison of Sedimentary Environmental Characteristic of Tidal Flats on the West Coast of Korea Depending on the Habitation of Mud Shrimp Upogebia major (서해안 갯벌 쏙(Upogebia major) 서식지와 비 서식지의 퇴적환경 특성)

  • Jeon, Seung Ryul;Hong, SokJin;Choi, Yonghyeon;Cho, Yoon Sik;Song, Jae-Hee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.6
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    • pp.656-665
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    • 2019
  • Environmental monitoring was conducted to identify the characteristics and patterns of sedimentary environments of tidal flats in 12 areas on the west coast of Korea. The habitat of the mud shrimp Upogebia major contained higher organic and mud contents compared to the habitat of the manila clam Ruditapes philippinarum. In particular, the mud content increased from 84.38% to 89.18% in the Seongam-4 area, where the mud shrimp and manila clam coexist, and the mean grain size exhibited a finer particle size, from 5.48 Φ to 5.80 Φ. In the mud shrimp habitat, the sediment mud content was > 60% and the mean grain size was > 5 Φ. Additionally, the mud shrimp only inhabited open coast tidal flat areas. The management of shellfish aquaculture farms by physical methods should be continued based on comparison of the sedimentary environments in the Boryeong and Seongam areas in response to the damage to the mud shrimp habitat.

Long-term Changes of Sediment and Topography at the Southern Kanghwa Tidal Flat, West Coast of Korea (한국 서해안 강화 남부 갯벌 퇴적물 및 지형의 장기적인 변화)

  • Woo, Han Jun
    • Journal of Wetlands Research
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    • v.15 no.4
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    • pp.493-500
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    • 2013
  • Comparisons of surface sediment distributions in summer 1997 and 2011 and elevations on the tidal flats in April 1998 and March 2013 had been used for understanding the long-term changes of sedimentary environments at southern Kanghwa tidal flat, west coast of Korea. The mud sediments dominated in the eastern part and sandy mud sediments dominated in the western part of the tidal flat in 1997. In 2011, the surface sediments were dominant mud and sandy mud at Sunduri and Tonggum in the eastern part, sandy mud at Tongmakri in the middle part, and sand and muddy sand at Yeochari and Changhwari tidal flats in the western part. The area of mud sediments had decreased, but that of sand-mud mixed sediments extended to eastward tidal flat for 14 years. The long-term topographic changes showed that deposition occurred at Tongmakri and Yeochari and erosion occurred at Changhwari tidal flat during 15 years. These changes should be effected the local hydrodynamic changes by several constructions near the tidal flat since the 1990s.

A Fundamental Study about the Applicability of Mud Flat as a Concrete Admixture and Filler (갯벌의 콘크리트용 혼화재 및 채움재로서의 활용가능성에 대한 기초적 연구)

  • Yang, Seong-Hwan;Kang, Yun-Young
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.6
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    • pp.571-578
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    • 2016
  • Recently, review on viability of various industrial by product and natural materials as raw material for concrete has been actively done in aspect of environment-friendly issue and depletion of natural resource. This study conducted fundamental study on the possibility of utilizing mud flat as admixture and filling material for concrete. First, chemical analysis on the viability of mud flat as admixture was done and the researchers compared it with the substance of fly ash and blast furnace slag. According to the result, substance content was proven to be inadequate. In addition, as the replacement rate of mud flat increased, compressive strength and tensile strength decreased. According to the estimated result of chemical substance analysis, possibility of utilizing mud flat as admixture was low. According to the result of experiment done as filling material, 10% ~ 30% replacement rate of mud flat manifested more than 8 Mpa of compressive strength of block which may be utilized for secondary product. However, additional experiment such as making block is required afterward. According to the result of flow experiment, as the replacement rate of mud flat increased, flow value decreased, and through chloride content analysis test, it was proven that mud flat is inappropriate to be applied as steel beam using structure since it has high content of sodium. It may be utilized as products that does not use steel beam such as internal brick.

Depositional Characteristics and Seasonal Change of Surface Sediment and Sedimentary Strucutre on the Doowoovi Tidal Flat, Southwestern Coast of Korea (한국 서남해안 두우리 조간대에서 표층 퇴적물 및 퇴적구조의 특성과 계절변화)

  • Baek Young Suk;Chun Seungsoo
    • The Korean Journal of Petroleum Geology
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    • v.10 no.1_2 s.11
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    • pp.10-17
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    • 2004
  • The Doowoo-ri tidal flat in the southwestern Korean coast is a typical open-coast tidal flat which has no barriers in the offshore such as barrier island and sand bars. The difference of induced wave energy with seasons is affected directly on the distribution of surface sediment and the formation of sedimentary structures because the sedimentation by wind wave is relatively much important element in this open-coast tidal flat. This open-coast tidal flat can be classified into tidal beach, intertidal flat and lower mudflat according to the pattern of geomorphology and sediment type. The intertidal flat can be again divided into 3 types: sand flat, mixed flat and mud flat based on the primary sedimentary structure and sand/mud ratio. Doowoori tidal flat shows a seasonal change in the surface sedimentary facies based on sediment composition and primary sedimentary structure. The change is closely related to the direction and magnitude of monsoon wind and also to storm frequency. In winter and spring, when northwesterly wind is most dominant and strong and also storms are common, sand-flat facies is largely distributed on the intertidal flat, whereas mud-flat facies is most dominant during summer when weak southeasterly wind is common. In the fall season, mixed-flat facies is dominant on the flat. The Doowoori intertidal flat is covered by mud sediment which is ca. 20 cm in thickness in summer season. In winter season, surface sediment is changed from mud to sand because the summer mud is mostly eroded by strong wave action. Can-core peels in the intertidal flat show that parallel laminated mud or sand/mud and climbing ripple cross-laminated sandy silt are dominant on the upper intertidal flat $(0-1.3 {\cal}km)$ during summer season. On the other hand, on lower intertidal flat $(1.7-2.3 {\cal}km)$, dominant sedimentary facies is homogeneous mud. In winter, it is changed into parallel laminated and ripple cross-laminated sand facies.

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Changes of Sedimentary Environments in the Southern Tidal Flat of Kanghwa Island (강화 남부 갯벌의 퇴적환경 변화)

  • Woo, Han-Jun;Je, Jong-Geel
    • Ocean and Polar Research
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    • v.24 no.4
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    • pp.331-343
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    • 2002
  • The southern tidal flat of Kanghwa Island with an area of approximately $90km^2$ is one of the biggest flats on the west coast of Korea. Surface sediments for sedimentary analyses were sampled at 83 stations in August 1997, September 1999 and August 2000. The very poorly-sorted mud sediments were predominant in the eastern part of the tidal flat, whereas the poorly-sorted sand-mud mixed sediments were dominant in the western part. The area of muddy sediment distribution diminished, but that of sandy mud sediment extended to southeastward tidal flat for three years. In the western part of tidal flat, deposition occurred during the period of spring to summer, whereas erosion occurred in winter. Sediment accumulation rates during three years indicated that the sediments deposited continuously in the eastern part of tidal flat, whereas eroded in the western part of tidal flat. Recently, construction of artificial structures such as new airport, island-connecting bridges and dikes near the tidal flat might change tidal current and river flow pattern. In order to reduce the ecological damage and to preserve tidal-flat environment, it is necessary to Investigate long-term impacts on sedimentary environment and ecology.

Characteristics of Blue Carbon Stock by Particle Size of Sediments in Unvegetated Tidal Flats : Hampyeong Bay and Dongdae Bay (비식생 갯벌에서 퇴적물 입도에 따른 블루카본 저장 특성: 함평만과 동대만)

  • Kyeong-deok Park;Dong-hwan Kang;Yoon Hwan So;Won Gi Jo;Byung-Woo Kim
    • Journal of Environmental Science International
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    • v.32 no.3
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    • pp.181-189
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    • 2023
  • In this study, sediment cores from unvegetated tidal flats in the Hampyeong Bay (west coastal wetland) and Dongdae Bay (south coastal wetland) were sampled, the blue carbon stock in the sediments was calculated, and the characteristics of the blue carbon stock were analyzed based on particle size of the sediments. The sediments in the Hampyeong Bay tidal flat had large particle size and low mud content, and the Dongdae bay tidal flat had small particle size and high mud content. The organic carbon content and blue carbon stock in the sediments were higher in the Dongdae tidal flat than in the Hampyeong Bay tidal flat. As a result of the regression function, in both the Hampyeong Bay and Dongdae Bay tidal flats, the sediments had the smaller particle size and higher mud contents the higher the organic carbon content and blue carbon stock. The sediments with smaller particle size had the larger specific surface area, so were feasible to adsorb and store more organic matters.