• Animal Systematics, Evolution and Diversity
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• 제28권1호
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• pp.12-19
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• 2012

A cyclopoid species from several salt marshes and estuaries on the west coast of South Korea were identified as Halicyclops continentalis Ueda and Nagai, 2009, recently described from Ariake Bay at northwestern Kyushu, Japan. Detailed examination on the Korean specimens justifies Ueda and Nagai's proposition that the H. sinensis sensu Tai and Chen, 1979 formerly known from the Chinese coast of the Yellow Sea should be identical to H. continentalis. Furthermore, this report reinforces their assumption on the geographical distribution of H. continentalis, that is, the Ariake Bay population is a continental relict of the East Asia continent. Herein, a redescription of the species is provided on the basis of the Korean specimens, with a comment on the morphological comparison among three populations around the Yellow Sea.

• 한국제4기학회지
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• 제3권1호
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• pp.47-54
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• 1989

현세 반담수와 염수습지 퇴적층에 함유된 황철석 ($FeS_2$)의 함량이 담수습지 퇴적층에서보다 상대적으로 많은 것으로 나타났다. 일본 히로시마 삼각주 퇴적층에서의 황철석 유황($FeS_2$-S)의 함량차이의 이유는 초기 현세동안에 고 해수면(palaeo-sea level)의 위치가 수백년 동안 같았으며 또한 배수가 잘 되지않은 염수습지가 현재의 평균해수면 보다 27m~28m 낮은 위치에 발달하였음을 지시한다.

• 한국해안·해양공학회논문집
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• 제33권1호
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• pp.13-29
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• 2021

본 연구에서는 해수의 유동에 관한 3차원 수치모델을 사용하여 경기만 한강 하구에서의 염 수송에 대한 메커니즘을 분석하였다. 수치모델의 모의 기간은 갈수기와 홍수기를 포함하는 2020년 1월 20일부터 9월 20일까지 약 245일이며, 모델 결과와 관측 자료의 비교를 통해 해수의 유동 및 염분 변화에 관한 수치모델의 재현성을 입증하였다. 한강 하구에서 염의 교환이 활발하게 이루어지는 염하수로의 북단과 남단 지역에 대해서 염 수송량(FS)을 산출하였다. 염 수송에 대한 발생 기작을 세부적으로 분석하기 위해 FS를 담수 유입에 의한 염의 이류 수송(QfS0), 수평 및 수직적인 유속 차이에 의한 염의 확산 수송(FE), 조석 변동성을 가진 유속과 염분의 위상 차이에 의한 염의 수송(FT)으로 분해하였다. 갈수기와 홍수기의 월 평균 염 수송량에 의하면, 두 기간 모두 외해로부터 한강 하구 지역으로 유입되는 염의 대부분은 FT에 의하여 강화도 남부 수로를 통해 수송된다. 반면에, 한강 하구로부터 외해로 유출되는 염의 대부분은 QfS0에 의하여 영종도 동부 수로를 통해 수송된다. 한강 하구에서 평균적인 염의 수송은 갈수기 동안 FT에 의하여 한강 하구의 상류 방향으로 수송되며, 홍수기 동안 QfS0에 의하여 외해 방향으로 수송된다. 결과적으로, 경기만 한강 하구에서의 염 수송은 외해 방향의 수송을 발생시키는 QfS0와 한강 상류 방향의 수송을 발생시키는 FT의 상호작용에 의하여 결정된다.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.264-276
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• 2021

Background: Salt marshes provide a variety of ecosystem services; however, they are vulnerable to human activity, water level fluctuations, and climate change. Analyses of the relationships between plant communities and environmental conditions in salt marshes are expected to provide useful information for the prediction of changes during climate change. In this study, relationships between the current vegetation structure and environmental factors were evaluated in the tidal flat at the southern tip of Ganghwa, Korea, where salt marshes are well-developed. Results: The vegetation structure in Ganghwa salt marshes was divided into three groups by cluster analysis: group A, dominated by Phragmites communis; group B, dominated by Suaeda japonica; and group C, dominated by other taxa. As determined by PERMANOVA, the groups showed significant differences with respect to altitude, soil moisture, soil organic matter, salinity, sand, clay, and silt ratios. A canonical correspondence analysis based on the percent cover of each species in the quadrats showed that the proportion of sand increased as the altitude increased and S. japonica appeared in soil with a relatively high silt proportion, while P. communis was distributed in soil with low salinity. Conclusions: The distributions of three halophyte groups differed depending on the altitude, soil moisture, salinity, and soil organic matter, sand, silt, and clay contents. Pioneer species, such as S. japonica, appeared in soil with a relatively high silt content. The P. communis community survived under a wider range of soil textures than previously reported in the literature; the species was distributed in soils with relatively low salinity, with a range expansion toward the sea in areas with freshwater influx. The observed spatial distribution patterns may provide a basis for conservation under declining salt marshes.

• 식품기술
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• 제24권2호
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• pp.281-289
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• 2011

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• 한국농공학회지
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• 제45권1호
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• pp.63-73
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• 2003

The settling of the dredged soil may vary with mineral composition, grain size distribution, initial water content and salt concentration of suspension of the site. A series of settling column test was performed to investigate the behaviour of solid suspension material from dredging and reclamation. Settling mode was divided into four types from the observation of interface and settling curves of clay minerals and marine clay samples, and the relationship charts of salt concentration and the initial water content were established to use in the dredging operation with any salt concentration. The critical initial water content which was defined as a threshold of zone settling and the consolidation settling was varied with salt concentration of water and was proportional to the plasticity of soil in sea water.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권3호
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• pp.130-135
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• 2001

In this paper, the distribution characteristics of salt contaminants with the distance from sea in East coast, from Sokcho to Pusan of Korea peninsula were investigated to evaluate the design standard of KEPCO. To get the equivalent salt deposit density(ESDD), conventional brush wiping method was used. As the measuring period is comparatively short, and the measuring interval is long to check the maximum value, acquired ESDD data is very lower than the recommended value in the standard. The measured data didn't follow normal distribution, so it should take the statistical treatment. Through normalizing method, we could get a reliable probability data. In the past investigation, the accumulation characteristics of Japan is consulted to set the criterion, but the climatic condition of Korea is different to Japan. With the comparison of precipitation data and some measured data for long tern accumulation, we could set appropriate accumulation factor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.2068-2069
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• 2007

This study describes a compairison leakage current properties between a polluted insulator and insulator subjected to salt polluted condition. Exposure tests at a sea coast test and the leakage current of insulators, climate conditions, and salt deposit density were measured during the tests. Appearance of leakage current for the insulator was affected by the humidity and the salt deposition on the surface. comparison of leakage current under salt polluted conditions. salt polluted test and humidity tests were carried out in laboratory using the same insulator profiles in oder to determine the leakage current patterns during critical conditions

• 한국수자원학회논문집
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• 제31권2호
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• pp.209-219
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• 1998

갑문을 통하여 유입되는 해수의 양을 산정하고, 1차원 수치모형을 적용하여 운하 속으로 해수의 확산 범위를 파악하였다. 복잡한 양상을 보이는 해수와 담수의 교환과정에서 조위, 갑식의 크기, 운하의 규모, 운영시간만을 고려한 개념적인 모형으로 표현하여 유입되는 해수의 양을 터미널로 배가 들오올 때와 나갈 때, 조위가 운하의 수위보다 높을 때와 낮을 때로 나누어 산정하였다. 본 연구에서 적용한 수치모형은 갑문을 통하여 유입되는 해수는 완전히 혼합된다고 가정하였으며, 또한 갑문을 열 때 갑실 속의 해수와 운하의 담수도 완전히 교환된다고 가정하였다. 서해 쪽 갑문을 통한 손실되는 물의 양을 한강 쪽의 갑문을 통하여 보충하는 경우와 그렇지 않은 경우로 나누어 고려하였다.