• Title/Summary/Keyword: SALINITY AREA

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THE VARIATION COEFFICIENT OF WATER TEMPERATURE AND SALINITY IN THE SOUTHERN SEA OF KOREA (韓國 南海의 水溫과 분의 變動係數)

  • Kim, Bok-Kee
    • 한국해양학회지
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    • v.17 no.2
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    • pp.74-82
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    • 1982
  • The study on the variation coefficient of water temperature and salinity was comducted during the year from 1968 to 1980 in the Southern Sea of Korea. The results obtaland from the study as followes; 1. The variation coefficient of water temperature and salinity wewe large either at the front area or the thermocline and malocline area. 2. The variation coefficient of water temperature was the largest at the time when the power was strong ty each water mass(The largest value in Tsushima and Yellow Sea Warm Current area was occurred at the 50m layer in the Summer, and that in the South Korean Coastal Water area and the Southern Part of Yellow Sea was at all layer in the Winter). 3. The variation coefficient of salinity was the largest at the surface layer in warm current area that was influenced by the low salinity of the East China Coastal Water in the Summer ,and that of salinity in the South Korean Coastal Water area and Soutern Part of Yellow Sea was nearly half of the value of the warm current area.

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Numerical Simulation on Hydrodynamic Characterization Changes Associated with the Construction of Dikes and Dredging Operations in Saemangeum Lake (새만금호 내 방수제 공사 및 준설에 의한 수리동역학적 특성 변화 수치 모델링)

  • Oh, Chan-Sung;Choi, Jung-Hoon;Cho, Young-Kweon
    • Journal of Environmental Science International
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    • v.22 no.9
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    • pp.1115-1129
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    • 2013
  • The study area is located on the western coast, and the inner development construction has been ongoing since 2011. The purposes of current study are to effectively simulate and quantitatively predict a temporal and spatial distributions of water temperature and salinity due to the stages of inner development construction in saemangeum reclaimed area. The transient-state numerical modeling using EFDC model is done, and the numerical simulation results are validated reasonably by repetitive numerical model calibration procedures with respect to field measurements of water temperature and salinity. The spatial distributions of water temperature and salinity show similar trends before and after construction of the dikes. In spring season, the salinity has maximum value of 21 psu, while, in summer season, the salinity shows 7 psu in a whole modeling domain. Thus, it is clearly observed that salt water is replaced by freshwater. However, the salinity and temperature reach their initial conditions at the end of the year. The salinity after construction of the dikes is lower than that before construction of them at Mankyeong area. On the other hands, after construction of the dikes, the salinity after dredging operations is higher than that before dredging. Because drastical increasing of water volume in Saemangeum Lake leads to increasing of stagnation time at bottom layer, and salt water is easily intruded to the two estuaries. Therefore, it may be concluded that hydrodynamic characteristics on Saemangeum are dominated by either Mankyeong and Dongjin discharge or sluice gates in/out-flow amounts, and thus they must be properly considered when rigorous and reasonable predictions of water temperature and salinity according to the stages of inner development construction.

Screening and Identification of Salt Tolerant Peanut (Arachis hypogaea L) Genotypes under Salinity Stress

  • Rizwana B.Syed Nabi;Eunyoung Oh;Myoung Hee Lee;Sungup Kim;Kwang-Soo Cho;Jeongeun Lee;Jung In Kim;Eunsoo Lee;Min Young Kim;Sang Woo Kim
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.113-113
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    • 2022
  • Salinity in surface waters is increasing around the world. Many factors, including increased water extraction, poor irrigation management, and sea-level rise, contribute to this change, and posing a threat to plant development and agricultural production. Seeds exposed to high salinity, have a lower probability of germinating and various physiological and biochemical effects. Salinity stress affects more than 20% of agricultural land and about 50% of irrigated land. In the current study, our objective is to identify the salt-tolerant peanut (Arachis hypogaea L.) Korean genotypes under salinity stress. Thus, two-week-old 19 diverse peanut Korean genotypes were exposed to 10 days of salinity (150 mM NaCl) stress. Based on the growth attributes investigation, Baekjung and Ahwon genotypes showed significantly higher shoot lengths compared to control plants. Whereas, the Sinpalwang genotype exhibited a significantly positive response for plant growth and reduced wilting symptoms compared to other genotypes. This study was able to find out peanut tolerant and sensitive genotypes for salt stress. These results may provide a good template for further salt-tolerant peanut cultivar improvement programs. Identified diverse salt-responsive genotypes can be utilized as source material in Korean breeding schemes for peanut crop improvement for salt and other abiotic stress tolerance.

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Environmental Characteristics and Catch Fluctuations of Set Net Ground in the Coastal Water of Hanlim in Cheju Island I. Properties of Temperature and Salinity (제주도 한림 연안 정치망어장의 환경특성과 어획량변동에 관한 연구 I. 수온 및 염분특성)

  • KIM Jun-Teck;JEONG Dong-Gun;RHO Hong-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.31 no.6
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    • pp.859-868
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    • 1998
  • In order to investigate the relation between the marine environmental characteristics and the change of the catch in set net, the marine environment properties were analyzed by temperature and salinity observed in the western coastal area of Cheju Island from 1995 to 1996 and the results are as follows 1) Main axis of Tsushima Current appeared in the western coastal area of Cheju Island was off 2$\~$3 miles from November to May. Therefore the waters of high temperature over $14^{\circ}C$ and high salinity from $34.40\%_{\circ}$ to $34.60\%_{\circ}$ were distributed homogeneously from surface to bottom in this time. But China Coastal Waters of low salinity appeared in the Cheju Strait from June to October, surface waters became of high temperature and low salinity, and middle and bottom waters became of the temperature from 11 to $14^{\circ}C$ and the salinity over $33.50\%_{\circ}$ and then vertically sharp thermocline and halocline are formed in the western coastal area of Cheju Island. In summer, the water temperature and salinity of the surface waters in wstern coastal area of Cheju Island were lower and higher respectively than that in middle area of the Cheju Strait and the temperature and salinity of the bottom waters in this area were higher and lower, respectively than that in middle area of the Cheju Strait. Such a distribution shows a tidal front in this coastal area. On the whole year, surface temperature and salinity were from 14 to $23^{\circ}C$ and from 30.60 to $34.60\%_{\circ}$, respectively, and annual fluctuation range of temperature and salinity was within $9^{\circ}C$ and $4.00\%_{\circ}$, respectively, Thus, annual fluctuation range in this area is much narrower than that in the Cheju Strait. In bottom water, temperature ranges from 14 to $20^{\circ}C$ through the year. Thus, the fluctuation range of temperature is narrow. The low temperature of from $11^{\circ}C$ to $13^{\circ}C$ appeared in the west enterance of Cheju Strait was not shown in this coastal area. 2) The salinity of bottom water was from $33.60\%_{\circ}$ to $34.40\%_{\circ}$ in 1995, while low salinity wale. below $32.00\%_{\circ}$ appeared all depth from June in 1996. Thus, the variation of hydrographic conditions in this area is narrow in winter, and wide in summer due to the influence of China Coastal Waters. 3) In summer, surface cold water, local eddy and fronts of temperature and salinity were showed within 2 mile from the west coast of the Cheju Island due to vertical mixing by tidal current. Especially, temperature and salinity of bottom water are changed with the change of depth around Biyang-Do. Thus, the front of temperature and salinity appeared clearly between shallow area with the depth of under 10 m and deep area with of the depth of more than 50m. Surface water in outside area where high temperature and low salinity water appear intrudes between Worlreong-Ri and Geumreung-Ri. Thus, the front of temperature and salinity was made along the line that connects from this coast to Biyang-Do, The temperature of the bottom water is $2^{\circ}C$ to $4^{\circ}C$ lower than that of the surface water and its salinity is $0.02\%_{\circ}$ to $0.08\%_{\circ}$ higher than that of the surface water even in shallow area.

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Oceanographic Condition of the Coastal Area between Narodo Is. and Solido Is. in the Southern Sea of Korea and Its Relation to the Disappearance of Red-Tide Observed in Summer 1998 (한국 남해 나로도와 소리도 사이 해역의 1998년 하계 해황 및 적조소멸과의 관계)

  • Choi, Hyun-Yong
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.6 no.2
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    • pp.49-62
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    • 2001
  • Hydrographic surveys were carried out seven times during May 31, 1998 and September 24, 1998 in order to study the physical environments of the coastal area between Narodo Is. and Sorido Is. in the southern sea of Korea (the South Sea) where the occurrence of Cochlodinium polykrikoides red tide is frequently observed in summer. Temperature and salinity of the water column from the surface to the depth of 30 m exhibit large seasonal variations. Mean temperature of the water column increased by 6 and mean salinity of the water column decreased by 2.71 psu during the observation period. Both the freshwater supplied from the adjacent land and the precipitation over the study area cannot account for the observed salinity variations. The influx of the low salinity water from the offshore area is considered to be the main cause for the observed salinity changes. Surface salinity in the study area shows different spatial distribution in the period of outbreaking, mid-stage and disappearance of the red tide. Especially, salinity was abruptly lowered at the stage of disappearance of red tide as compared to salinity of the previous observation period. Vertical structure of water properties also became vertically homogeneous at the disappearance stage, while it was highly stratified in the previous observation. Such changes can only be explained by the inflow of low salinity water from the offshore, which is considered as the most possible cause for the disappearance of the red tide in the study area. This study suggests that exchanges of water, and chemical and biological factors between coastal areas and of shore area in the South Sea need to be studied in association with the general circulation of the South Sea in order for the better understanding of the occurrence and disappearance of the red tide in the coastal area of the South Sea.

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Classification of Soil Desalination Areas Using High Resolution Satellite Imagery in Saemangeum Reclaimed Land

  • Lee, Kyung-Do;Baek, Shin-Chul;Hong, Suk-Young;Kim, Yi-Hyun;Na, Sang-Il;Lee, Kyeong-Bo
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.426-433
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    • 2013
  • This study was aimed to classify soil desalination area for cultivation using NDVI (Normalized difference vegetation index) of high-resolution satellite image because the soil salinity affects the change of plant community in reclaimed lands. We measured the soil salinity and NDVI at 28 sites in the Saemangeum reclaimed land in June 2013. In halophyte and non-vegetation sites, no relation was found between NDVI and soil salinity. In glycophyte sites, however, we found that the soil salinity was below 0.1% and NDVI ranged from 0.11 to 0.57 which was greater than the other sites. So, we could distinguish the glycophyte sites from the halophyte sites and non-vegetation, and classify the area that soil salinty was below 0.1%. This technique could save the time and labor to measure the soil salinity in large area for agricultural utilization.

Fluctuation Characteristic of Temperature and Salinity in Coastal Waters around Jeju Island (제주도 연안 천해역의 수온 · 염분 변동 특성)

  • KO Jun-Cheol;KIM Jun-Teck;KIM Sang-Hyun;RHO Hong-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.3
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    • pp.306-316
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    • 2003
  • We conducted a time-series analysis of temperature and salinity of sea water around Jeju Island, Korea. Monthly mean temperature and salinity was influenced by precipitation and weather conditions on Jeju as well as by oceanographic conditions of the open sea such as the Tsushima Warm Current and sea water in coastal areas. Salinity of Jeju coastal waters was the highest in April, and it was always over 34.00 psu with tiny fluctuation between December and June. Due to the effects of the Tsushima Warm Current, Jeju coastal waters maintained high salinity and stability. Low salinity and its large fluctuations during summer were closely associated with the China Coastal Water and precipitation in Jeju. The place of the lowest water temperature was the northeast coasts of Jeju (Gimneong, Hado, Jongdalri). In winter, as warmer water of the Tsushima Warm Current appeared in western area of Jeju dwindled flowing along the northern coasts of Jeju area and becoming cool, the lowest water temperature often appeared locally in Gimnyeong and its vicinitly in summer. The Tsushima Warm Current flows into the east entrance of Jeju Strait, but its influence is weak because of geometry and strong vertical mixing due to fast tidal currents.

A Study on Eating Out Behavior and Recognition of Salinity in Restaurant Food in Jecheon Area (제천지역 외식업소 방문객의 외식행동 및 외식음식 염도인지에 대한 조사)

  • Park, Soojin;Min, Sung Hee
    • Journal of the Korean Society of Food Culture
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    • v.30 no.1
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    • pp.20-28
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    • 2015
  • In this study, the eating out behavior and recognition of salinity in restaurant food in Jecheon area were examined. Demographic characteristics of the subjects, eating out behavior and perception of salinity in food purchased in restaurants were surveyed. Also salinity of the high Na-containing menus were measured using salimeter. Exactly 51.6% of the study subjects usually ate out more than one to two times per week. A large percentage (88.6%) of the subjects mentioned that they ate more than half the amount of liquid in their dishes. The study participants recognized that the salt concentrations of stews, soups and noodles in their orders were high. JJamppong was recognized as the most salty among nine kinds of eating out menus, whereas mulnaengmyeon was the least. Although the recognized salt concentration of mulnaengmyeon was relatively low, this dish had the highest salinity out of nine eating out menus. Relative salinities of eating out menus were higher than absolute salinity mostly except yukgaejang. It is necessary to supply exact nutrition information and widely implement nutrition labeling. Furthermore, consumers should personally be careful to limit consuming food with high sodium levels when dining at restaurants and eat less liquid in dishes.

Estimation Method of Airborne Salinity for Durability Design of Reinforced Concrete Structure (철근콘크리트 구조물의 내구성 설계를 위한 비래염분 추정방법)

  • Ham, Hee Jung
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.29-36
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    • 2007
  • A comparative study of airborne salinity and sea wind was done for a coastal area, Sokcho city, of East Sea in Kangwon province, Korea. In this study, a relationship between the formation of airborne salinity and wind velocity was investigated, and then the airborne salinity was simulated and forecasted by the obtained wind-salinity characteristics. It is founded that most airborne salinity is brought by sea winds with the occurrence of velocity, higher than and equal to 4m/s, while the occurrence of lower wind velocities (ie., lower than 4m/s) in sea wind and the occurrence of inland wind give diluted effects on the airborne transfer. By using these characteristics and a proposed linear equation model, the salinity in Sokcho city is successfully simulated and forecasted. It is expected that the linear equation model may be useful for durability design of concrete structures under the conditions of chloride attack, induced by the airborne salinity.

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Low-salinity Water and Circulation in Summer around Saemangeum Area in the West Coast of Korea (하계 서해안 새만금 연안역 주변 저염수와 순환)

  • 이상호;최현용;손영태;권효근;김영곤;양재삼;정해진;김종구
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.2
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    • pp.138-150
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    • 2003
  • In the mid-west coast of Korea where Mankyung and Dongjin rivers discharge fresh water, Saemangeum tidal dyke of 33 km long is under construction to reclaim the very shallow estuary region of 41,000ha. Main source of freshwater in this coastal area is Keum River locating closely north of the dyke. At present, the dyke connected with Gogunsan-Gundo separates this area into three regions; northwestern, southwestern and eastern (Saemangeum) region of the dyke, and the water in Saemangeum region is exchanged through one gap in the northern dyke and two gaps in the southern dyke. We have observed distributions and structures of temperature and salinity to examine the summer circulation related with low-salinity water in this coastal area in 1998 and 1999. In the surface layer off the northern dyke a tongue-like distribution of low-salinity extends 60 km long from Keum River estuary mouth to the northwest, forming plume front bounded by offshore water. In the inner region of Saemangeum dykes salinity distributions show that two river waters are merged together and the low salinity water is deflected toward northern gap of the dyke. In the surface layer off the southern dyke we observed small tongue-like distribution of another low-salinity water extending to the north from Gomso Bay. Based on the analysis of distributions of low-salinity water and frontal structures, we can suggest an anticlockwise circulation of coastal water around the dyke, composed by the estuarine water outgoing from the inner region of the dyke through the northern dyke's gap and the inflow through two gaps of southern dyke from offshore. After completing the dyke construction, this coastal circulation around the dyke will be, however, changed because fresh water discharge of Mankyung and Dongjin rivers will be routed artificially and directly into the area offshore of the southern dyke.