• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.6
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• pp.353-360
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• 2010

The Kyunggi Bay in mid-west of Korea is a relatively large estuarine system that connects the Han River system with Yellow Sea. Due to macro-tidal range of more than 8 m, the urban estuary shows deep tidal channels and wide tidal flats. Since last 30 years, the coastal development is undergoing, yielding noticeable change in environment. Particularly the tidal flat dynamics are generally accepted as being related with tidal residual flows in this area (Kim et al., 2009). We have estimated the annual variation and vertical structure of residual currents with one-year long observed flows in two major tidal channels of Kyunggi Bay. The moving average method and tidal current harmonic analysis yield nearly the same results on residual flow. The residual flow in Jangbong channel ranges from 20 cm/s in summer to 30 cm/s in winter. It is noticeable that the residual flow in Jangbong channel is flood dominant throughout the year, while the flow in Seokmo channel is ebb-dominant residual flow with current speed range of 20-40 cm/s. Due to the baroclinic response of relatively shallow estuary, significant reduction of energy in bottom layers have been observed, indicating the importance of residual circulation to the tidal flat behavior.

• Journal of Wetlands Research
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• v.8 no.3
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• pp.29-38
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• 2006

Digital Elevation Model (DEM) of intertidal flat can be widely used not only for scientific fields, coastal management, fisheries, ocean safety, military, but also for understanding natural and artificial topographic changes of the tidal flat. In this study, we generated DEM of the Ganghwado southern intertidal flat, the largest tidal flat in the west coast of the Korean Peninsula, using waterline method and interferometric synthetic aperture radar (InSAR). Constructed DEM which applied waterline method to the Landsat-5 TM and Landsat-7 ETM+ images closely expresses overall topographic relief of tidal flat. We found that the accuracy was determined by the number of waterlines which reflect various tidal conditions. The application of InSAR to the ERS-1/2 and ENVISAT images showed that only ERS-1/2 tandem pairs successfully generated DEM in the part of northern Yeongjongdo, but construction of DEM in the other areas was difficult due to the low coherence caused by a lot of surface remnant waters. In the near future, Kompsat-2 will provide satellite images having multi-spectral and high spatial resolution within a relatively short period at different sea levels. Application of waterline method to these images will help us construct a high precision tidal flat DEM. Also, we should develop DEM generation method using single-pass microwave satellite images.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.2
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• pp.31-48
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• 2014

This study is carried out to offer the raw data for conservation and management of tidal flat ecosystem by surveying and analysing the flora distributed in Daesong tidal flat wetland, Ahnsan-si, Gyeonggi-do coast, Korea. The results of surveying the flora were recorded as 186 taxa including 45 families, 121 genera, 170 species, 14 varieties and 2 forms. The halophytes checked around this site were 20 taxa including Atriplex gmelinii, Salicornia europaea, Suaeda glauca, Suaeda japonica, Phragmites communis, Carex scabrifolia and so forth. Polygonum bellardii that species had ecological value was the specific plant by floristic region. The growth locations of halophytes were 11 taxa of upper, 4 taxa of high tide line and 5 taxa of lower. The naturalized plants were 42 taxa including Phytolacca americana, Chenopodium glaucum, Melilotus alba, Veronica persica, Bidens pilosa, Leptochloa fusca and so forth. Because Aster subulatusand Leptochloa fusca grew a upper tidal flat wetland, they had the characteristics of halophytes. The focuses on the management of Daesong wetland were halophytes and naturalized plants. Firstly, to maintain a halophytes communities, we will sow the halophytes seeds and plant the individuals. And In-Situ conservation was applied to Polygonum bellardii habitat. Secondly, to prevent the genesis of naturalized plant, we will don't disturb around the wetland environment. The invasive alien plant, Lactuca scariola, was removed by periodic monitoring and purification activity.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.28-31
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• 2010

충청남도 서해안은 생태환경의 보고로서 갯벌, 사구, 해안습지 등 독특한 자연적 특성을 갖고 있는 지역이다. 그러나 다른 지역에 비해 대규모 간척 및 매립으로 인한 해양생태계 피해에 현저히 노출되어 있고, 최근 산업화 및 관광권화가 진행되고 있으며 해안선 침식 방지를 위한 연안정비사업으로 각종 연안 방호구조물이 건설되었다. 이 중 가장 많이 건설된 연안 호안구조물은 배후지역의 안정성 확보, 해안도로의 건설 등 다양한 목적으로 축조되었다. 그러나 성장위주의 경제정책으로 연안 호안구조물이 무분별하게 설치되어 파도와 호안 구조물의 접촉 시 호안구조물이 파랑을 견디지 못해 사면피복재가 산란되어 외관상 주변 환경을 해칠 뿐만아니라 2차 피해까지 야기 시킬 우려가 있다. 본 연구에서는 호안구조물의 리모델링을 통해 안정성을 증대시키기 위해 서해 연안지역의 4개 시 군 29개 지점을 대상으로 호안구조물 현황에 대해 조사하고 호안구조물의 리모델링을 통해 붕괴된 지역을 대상으로 파랑에 대해 안정한 사석재 소요질량을 호안구조물의 경사 별로 산정하여 비교하였다. 피복재 소요질량 산정을 위한 설계파고는 유의파고를 적용하였으며, 산정공식은 허드슨공식(Hudson, 1959)을 사용하였다. 추가적으로 사석 층의 두께와 단위면적당 수용해야할 사석재의 개수를 산정하여 호안구조물 설계 시 사석재의 배치를 용이하게 할 수 있도록 하였다. 본 연구에서 산정된 값들은 초기설계로서 파랑에 안정한 호안구조물의 설계 조건 중 일부분으로 호안구조물의 최종 설계 시 조파실험을 통하여 안정성을 검증 해야 할 것으로 판단된다.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.86-92
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• 2012

Halophyte samples, such as Suaeda japonica, Phragmites australis, Limonium tetragonum, Suaeda maritima were collected from Go-chang salt marsh. Thirty-nine endophytic fungal strains were isolated from the roots of halophytes naturally growing in salt marsh. All endophytic fungal strains isolated were analyzed by internal transcribed spacer (ITS) containing ITS1, 5.8 s and ITS2 region. Endophytic fungal strains belong to eight orders, i.e., Eurotiales (36%), Pleosporales (26%), Hypocreales (18%), Incertae sedis (8%), Glomerellales (5%), Sordariales (2%), Xylariales (2%), and Capnodiales (3%). On genus level, they were composed of Alternaria, Aspergillus, Chaetomium, Cladosporium, Colletotrichum, Coniothyrium, Dothideomycete, Fusarium, Gibberella, Macrophoma, Penicillium, Pestalotiopsis, Phaeosphaeria, Phoma, Pleosporales, Pseudozyma, Talaromyces, and Termitomyces. Of them, Penicillium (26%), Fusarium (13%) of Eurotiales and Hypocreales were predominant.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.409-426
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• 2013

The purpose of this study is to present the raw data for management and conservation of tidal flat by objective surveying and analysing the halophytes and vegetation distributed in Seocheon tidal flat wetland conservation area, Korea. The results are as follows. The numbers of halophytes in this site were summarized as 27 taxa including 13 families, 21 genera, 26 species and 1 variety. In the results of ecologically important species, rare plant was 1 taxa, 10 taxa of the specific plants by floristic region, 1 taxa of naturalized plant and 1 taxa of the plant with approval for delivering oversea. The life form spectrum consisted of therophytes(44.4%), hemicryptophytes(25.9%), geophytes(14.8%), nanophanerophytes(7.5%), chamaephytes and hydatophytes(each 3.7%). The types of vegetation of Seocheon tidal flat wetland conservation area were classified with 17 communities including Vitex rotundifolia community, Suaeda maritima community, Calystegia soldanella community and so forth. In the halophytes composition, section C and E-1 had the largest character species and companion species. In the results of vegetation amount, section C, D, E-1 and E-2 were the highest score, on the other hand, section A and B were the lowest. The final rating was calculated by adding up values of two factors, and section C and E-1 had the highest rating of II. In future, we will survey the whole flora in Seocheon tidal flat, we will offer the help to establishing the conservation plan of coastal plant ecosystem in West Sea.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.281-291
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• 2014

In March to August 2013, the emission of gases ($CH_4$, VOC, $CO_2$, $O_2$, and LEL) was measured three times from the intertidal flat sediments at Sogeun-ri, Taean-gun, in the Mid-western seashore of Korea by using chamber method. After analyzing gas emission concentrations inside of flux enclosure chamber by using a GC equipped with Agilent 6890. The gas emission fluxes were calculated from a linear regression of the changes in the concentrations with time. The ranges of gas flux during the experimental period were $+0.06{\sim}+0.60mg/m^2/hr$ for $CH_4$, $+58.45{\sim}+95.58mg/m^2/hr$ for $CO_2$, $-0.02{\sim}-0.20mg/m^2/hr$ for $O_2$, and $-0.60{\sim}+0.65mg/m^2/hr$ for VOC, respectively. The flux measurement results revealed that $CH_4$ fluxes during March in the relatively low sediment temperature ($14.5^{\circ}C$) were significantly higher ($+0.60mg/m^2/hr$) than during June and August ($+0.06{\sim}+0.18mg/m^2/hr$) in high sediment temperature ($32.0{\sim}36.8^{\circ}C$). $CH_4$ flux to mean size of sediments and temperature of inner chamber exhibited strong positive correlation ($R^2=-0.97$ and $R^2=-0.89$, respectively).

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.2
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• pp.171-185
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• 2013

Wetland has been known as a major biogenic source of $CH_4$ in globe. In a global scale, the amounts of 55~150 Tg $CH_4$ are released into the atmosphere annually from wetlands; and it accounts for about 21% of total $CH_4$ annual global emission. From August 2010 to August 2011, measurements of major greenhouse gas ($CO_2$, $CH_4$, $N_2O$) emissions were conducted from a freshwater wetland at Kunsan ($35^{\circ}56^{\prime}38.94^{\prime\prime}N$, $126^{\circ}43^{\prime}16.62^{\prime\prime}E$), Korea by using floating closed static chamber method. Flux measurements for these gases from western coastal tidal flat at Seocheon ($36^{\circ}07^{\prime}13.85^{\prime\prime}N$, $126^{\circ}35^{\prime}43.18^{\prime\prime}E$), Korea were managed from July 2011 to February 2012 by using closed static chamber method. The average gas fluxes and ranges from freshwater wetland experiment were $0.155{\pm}0.29\;mg\;m^{-2}\;hr^{-1}$ (-0.054~0.942 $mg\;m^{-2}\;hr^{-1}$) for $CH_4$, $17.30{\pm}73.27\;mg\;m^{-2}\;hr^{-1}$ (-52.44~261.66 $mg\;m^{-2}\;hr^{-1}$) for $CO_2$, and $0.004{\pm}0.01\;mg\;m^{-2}\;hr^{-1}$ (-0.02~0.07 $mg\;m^{-2}\;hr^{-1}$) for $N_2O$, respectively. Monthly base flux measurement results revealed that $CH_4$ fluxes during summer months in high water temperature were significantly high, and at least order of one higher than those during other months. The average fluxes and ranges of these greenhouse gases from tidal flat during the experimental period were $0.002{\pm}0.08\;mg\;m^{-2}\;hr^{-1}$ (-0.16~0.22 $mg\;m^{-2}\;hr^{-1}$) for $CH_4$, $-31.18{\pm}75.33\;mg\;m^{-2}\;hr^{-1}$ (-298.87~101.93 $mg\;m^{-2}\;hr^{-1}$) for $CO_2$, and $0.001{\pm}0.01\;mg\;m^{-2}\;hr^{-1}$ (-0.017~0.03 $mg\;m^{-2}\;hr^{-1}$) for $N_2O$, respectively. Comparing the results of gas emissions from tidal flat to those from freshwater wetland, we found significantly lower emissions from tidal flat based on the experiment. Physicochemical parameters of water and soil at these experimental plots were also sampled and analyzed for understanding their correlation with these gas emissions.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.254-260
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• 2014

Sulfur compound includes major electron acceptors for anaerobic respiration. In this study, cultivation-based study on sulfate- and sulfur-reducing bacteria of various wetlands of Korea was attempted. To isolate sulfate- and sulfur-reducing bacteria, anaerobic roll tube method was used to obtain typical black colonies of sulfate- and sulfur-reducing bacteria. Total 11 strains obtained were tentatively identified based on comparative 16S rDNA similarity and physiological property analysis. All sulfate-reducing bacteria (8 strains) belonged to genus Desulfovibrio with >99% 16S rDNA similarities. Three sulfur reducing bacteria were also isolated: two and one isolates were affiliated with Sulfurospirillum and Desulfitobacterium, respectively. These sulfate- and sulfur-reducing bacteria were able to utilize lactate and pyruvate and sulfite and thiosulfate as common electron donors and electron acceptors, respectively. This case study will provide fundamental information for obtaining useful indigenous sulfate- and sulfur-reducing bacteria from Korean wetlands employing various combinations of cultivation conditions.

• Journal of Korean Society of Forest Science
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• v.63 no.1
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• pp.1-8
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• 1984

These surveys were conducted to estimate the winter bird population inhabiting in the estuary of Nakdong River by unit distances, by unit times, by sections and by observation points. The results were summarized as follows: 1) A total of 70,032 birds were observed, which composed of 82 species under 27 families. 2) An average of 2,103.06 individuals per kilometer was observed and 23,344.00 individuals per hour. Anatidae showed the most dominance (65.13% of the total), followed by Scolopacidae(14.55%), and Laridae(7.28%). 3) The present population by areas were observed as follows; 61.8% of the total in the tideland and swamp, 31.9% in the surface of water, and 6.4% in the air and land, respectively. 4) Among the five sections, the greatest population was observed in section 3 which figured 22,852 individuals (30.0%), and the least in section 4 (9.8%). 5) In this observation point, six species such as Anas platyrhynchos, Tadorna tadorna, Anser albifrons, Aythya ferina, Calidris alpina and Larus crassirostris were the most dominant birds inhabiting which reached 83.1% of the total.