• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1982-1985
• /
• 2010

해수침투는 대수층의 염분 농도를 증가시켜 지하수 염분화에 의한 용수의 부족 등을 야기시키며 다른 지하수 오염과 마찬가지로 회복에 대한 막대한 비용과 시간이 소모되어 피해지역에 대한 정확한 현황파악이 어려워 피해방지대책의 수립이 필요한 실정이다. 따라서 본 연구에서는 흐름과 이송을 모의할 수 있는 GMS-FEMWATER 모델을 이용하여 대상지역의 지층구조를 구분하고 실제 대상지역의 지층과 동일하게 모델링하여 해안지역의 해수침투에 대한 특성을 규명하였다. 분석결과 양수기간이 길어 질수록 지하수두강하 폭이 양수기간 30일, 60일, 90일 및 180일 경과 시 초기 수위에서 점차 4.25m (1.36%), 3.5m (1.13%), 2.96m (0.97%), 1.97m (0.65%)으로 감소하는 것을 알 수 있었다. 또한 양수량이 많은 관정일수록 해수 침투가 큰 것을 알 수 있다. 양수기간 30일 0.59mg/l, 채수 60일 1.65mg/l, 채수 90일 3.14mg/l, 180일 5.55mg/l으로 분석되었다. 이결과로 볼 때 양수기간 초기에서 기간이 지날 수록 해수침투가 큰영향을 주는 것을 알 수 있었다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.5
• /
• pp.398-404
• /
• 1993

This study was conducted in order to obtain the information for yield improvement in saline paddy. Saline concentration, growth and yield of rice, being subjected to different flooding times and days to transplanting were investigated in saline paddy with 0.35 % and 0.5 % salt concentration. Saline concentration of soil was increased to 0.41 % just after rotary in the paddy with 0.35 % salinity, but decreased to 0.20 % after 3 to 4 times of flooding treatment. And also that of surface water was decreased from 0.2 % to 0.11 %. Saline concentration of soil in 5cm depth was decreased to 0.31 % by one time flooding and to 0.22% by 3～4 times flooding but salinity below 7cm depth showed slight decrease. Seedling death was exceeded 37 % when transplanted one day after rotary in the paddy with 0.35% salinity. Death ratio was decreased to 20% by three times flooding and transplanting six days after rotary. In paddy with 0.5 % salinity, death ratio was high but the tendency was very similar to 0.35 % field. In 0.35 % saline paddy field, yields were increased by 14 % by three times flooding and transplanting six days after rotary as compared to one time flooding and transplanting are day after rotary. Therefore, 3 to 4 times flooding and transplanting 5 to 6 days after rotary are desirable in high saline paddy.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2003.10a
• /
• pp.23-23
• /
• 2003

김 붉은갯병은 김 엽체에 난균류 Pythium속의 Pythium porphyrae의 기생에 의해 발생되어 매년 김 양식에 큰 피해를 주는 매우 심각한 김 갯병중의 하나이다. 최근에는 이들 병해의 발생 및 억제를 위한 김 산처리제 (활성처리제) 남용에 따른 연안 양식어장의 생태계 파괴 및 김의 자연식품에 대한 이미지 훼손 등의 문제점이 대두되고 있다. 따라서 본 연구에서는 김 양식시 발생되는 붉은갯병의 병해를 억제하고자 활성처리제 처리시 고염분해수 처리를 병용함으로써 활성처리제의 사용을 최소화하면서 처리효과를 배가시키고자 하였다. 시험에 사용한 김 엽체는 2002년 10월에 전라남도 해남군 황산면 지선에서 채묘한 방사무늬김 (Porphyra yezoensis)을 육묘해 엽장 1cm 내외에서 냉동망을 제작하여 -2$0^{\circ}C$에 저장한 엽체를 자연해수 (약 27$\textperthousand$), 15$^{\circ}C$, 100$\mu$mol photon m$^{-2}$ s$^{-1}$, 광주기 9L : 15D의 배양조건하에서 15일간 배양한 엽장 3-4cm 정도의 것이었다. 활성처리제와 고염분해수처리제의 병용에 의한 붉은 갯병 억제효과는 붉은갯병 병원균의 유주자를 김 엽체에 감염시킨 후 27$\textperthousand$의 자연해수에 12일간 배양하면서 염분농도를 3-25%, 처리주기를 1-2회로 하여 각 시험구별 병해정도로 평가하였다. 고염분해수 처리에 의한 붉은갯병균 균사의 생장억제 효과는 김 엽체를 붉은갯병 병원균의 유주자로 감염시킨 다음 감염 12시간 후 염분농도를 3-25%로 처리한 후 27$\textperthousand$의 자연해수에 4일간 배양하면서 각 시험구별 배양시간에 따른 병원균 균사에 의한 김 엽체의 감염세포수로 평가하였다. 활성처리제와 고염분해수처리제의 병용이 김 엽체 생장에 미치는 영향은 건전한 김 엽체의 절편을 27$\textperthousand$의 자연해수에 배양하면서 시험구별로 활성처리와 고염분해수 (5, 10, 15, 20, 25%) 처리를 3일 간격으로 하면서 12일간 배양한 후 엽체의 엽면적 증가율로 평가하였다. 활성처리제와 고염분해수처리제의 병용에 의한 붉은갯병의 억제효과는 대조구 (활성처리 1회)와 비교해 주 2회의 활성처리구와 염분농도 20, 25% 처리구에서 병해 억제효과가 월등히 높았다. 고염분해수 처리에 의한 붉은갯병균 균사의 생장억제 효과는 염분농도 5, 10% 처리구의 경우 무처리구에 가까운 감염세포수를 보였으나, 염분농도 20, 25% 처리구의 경우 활성처리제 처리와 비슷한 감염세포수를 보여 뚜렷한 생장 억제효과를 나타냈다. 활성처리와 고염분해수 처리의 병용이 김 엽체 생장에 미치는 영향은 대조구 (활성처리 1회)의 3.4배 생장율과 활성처리와 염분농도 5-20%의 고염분해수 병용 처리구의 3.1-3.6배 생장율은 유의한 생장차이를 보이지 않았다 (P<0.05).

• 한국해양학회지
• /
• v.1
• /
• pp.49-55
• /
• 1971

After the heavy precipitation from April 1969 to September 1970, more than 1.359 10$\^$6/㎥ of fresh water was discharged through diversion channel of the Namgang Dam. The sands and muds in the northern Sachon Bay were moved and swept away by the strong southsard flow which was observed to be speedier than five knots. The shellfish culture facility as well as the oysters and bivalves were buried. In Sachon Bay, a southward surface ebb current of approximately one knot stratifies above the northward flow of approximately 0.5 knot, which seems to be similar to the salt wedge estuary. The stratified current is responsible for the breaking of the gill nets and other fishing gears. The salinity of sea water in Chinju Bay decreased remarkably and the abnormal low salinity water lower than 5 was distributed in Sachon Bay. The low salinity water front was observed in eastern Chinju Bay and the Samchonpo Channel, where the salinity was increased from 4.6 to approximately 30 within half a tidal cycle. These caused the oysters and bivalves die, and drove anchovies and octopus out to the sea and prevented them from approaching the bay. The decrease of salinity causes the decrease of density and osmotic pressure of sea water. Turbid water would prevent the sunlight from penetrate into deep layer.

• Korean Journal of Remote Sensing
• /
• v.37 no.5_2
• /
• pp.1307-1315
• /
• 2021

The Changjiang Diluted Water (CDW) spreads over the East China Sea every summer and significantly affects the sea surface salinity changes in the seas around Jeju Island and the southern coast of Korea peninsula. Sometimes its effect extends to the eastern coast of Korea peninsula through the Korea Strait. Specifically, the CDW has a significant impact on marine physics and ecology and causes damage to fisheries and aquaculture. However, due to the limited field surveys, continuous observation of the CDW in the East China Sea is practically difficult. Many studies have been conducted using satellite measurements to monitor CDW distribution in near-real time. In this study, an algorithm for estimating Sea Surface Salinity (SSS) in the East China Sea was developed using the Geostationary Ocean Color Imager (GOCI). The Multilayer Perceptron Neural Network (MPNN) method was employed for developing an algorithm, and Soil Moisture Active Passive (SMAP) SSS data was selected for the output. In the previous study, an algorithm for estimating SSS using GOCI was trained by 2016 observation data. By comparison, the train data period was extended from 2015 to 2020 to improve the algorithm performance. The validation results with the National Institute of Fisheries Science (NIFS) serial oceanographic observation data from 2011 to 2019 show 0.61 of coefficient of determination (R²) and 1.08 psu of Root Mean Square Errors (RMSE). This study was carried out to develop an algorithm for monitoring the surface salinity of the East China Sea using GOCI and is expected to contribute to the development of the algorithm for estimating SSS by using GOCI-II.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.543-544
• /
• 2011

오손에 의한 송전선로 사고 발생 피해를 최소화하기 위해서는 오손시점을 정확히 진단하고 대비하는 것이 필요하다. 송전선로의 오손 정도는 등가염분부착밀도(ESDD) 측정값을 통해 분류하고 있으며, 오손 정도에 따라 철탑과 송전선로 도체의 절연을 담당하는 애자(Insulator)의 수량 설계 및 청소 주기가 결정되어 운영되고 있다. 그러므로 정밀한 측정이 필수적인데, 기존 필세법에 의한 오손 측정방법은 세정 및 측정 방법에 따라 결과 값의 편차가 발생할 요소가 많아 개선이 필요하다. 이에 본 논문은 기존 필세법에 의한 측정 방법을 분석하여 개선 요소를 확인한 후 실험계획법에 따라 분석하여 측정 정밀도를 향상하는 방법을 제시하고자 한다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.6
• /
• pp.483-488
• /
• 1993

This study was conducted to obtain the basic information for easily judgement to level of salinity stress of the reclaimed land. Rice varieties used were Nakdongbyeo and Chilsungbyeo. In seedling stage, 13 day-old seedlings were subjected to salt solution (0, 30, 60, 90mM) for 8 days. In reproductive stage, 30 day-old seedlings were transplanted 3 hills(3 seedlings /hill) per plastic pot (diameter 28${\times}$depth 30cm). Salinity stress was given by immersing pot in the salt solution(sea water) with 4 concentrations(0, 30, 60, 90mM)for 8 days at booting stage. The stomatal resistance was increased with salinity concentrations. Salinity stress appeared to be more sensitive in seedling stage than in reproductive stage in each concentrations. The photosynthesis was decreased in salinity treatment. Salt-treated periods influenced unfavorably stomatal resistance in each stages. The leaf chlorophyll content was remarkably decreased by increasing salt concentrations. The absorption of Na+ and Cl￣ were increased as salt concentration in the culturing medium became higher, but there was no appearent difference in the absorption of K+, Mg++, and Ca++. The plant height and root length were decreased in salinity treatment. The inhibitory effect of salinity stress on root growth was more severe than in shoot growth. The stomatal resistance could have been used as bio-information.

• Journal of fish pathology
• /
• v.10 no.2
• /
• pp.113-123
• /
• 1997

Concerned to the life cycle of Ichthyophthirius multifiliis, the biological characteristic of the parasites was studied in the rainbow trout (Oncorhynchus mykiss) and the Korean catfish (Silurus asotus) Under the experimental condition of $9^{\circ}C$- $28^{\circ}C$, tomitogenesis rate was positively proportional to water temperature, but not at over $28^{\circ}C$. The protomonts showed a high rate of tomitogenesis at $26^{\circ}C$ in comparision with other temperature conditions. Temperature affected tomitogenesis rate which resulted from the various conditions of salinity, pH and formalin concentration. The protomonts showed a high rate of tomitogenesis at pH 6.9 in comparision with other pH conditions at all temperatures tested. This result revealed that the opitimum pH for tomitogenesis was 6.9. The protomont had more tolerance against salinity and formalin concentration at low temperature ($18^{\circ}C$) than at high one ($22^{\circ}C$). Both trophont and protomont were not infective, but theront was infective.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.2
• /
• pp.122-126
• /
• 1998

This experiment was conducted to verify the responses of major crop species to saline stress.To determine the saline tolerance of crop species, sevral crop species were cultivated under sand-culture system using Hoagland's nutrient solution whit 200mM NaCl. The crop species showing saline tolerance were cotton(Gossypium indicum), maize(Zea mays), barely(Hordeum vulgare), and wheat(Triticum aestivum) but perilla (Perilla frutescens) and leguminous crops, mung bean(Phaseolus radiatus), azuki bean(Phaseolus angularis) and soy bean(Glycin max) showed very por tolerance. One the typical symptom was the darkening of leaf color due to increase of chlorophyll concentration.Among of the plant families, Fabaceae was the most susceptible but crop species belonging to Poaceae were more proper for cultivating on reclaimed tidal land in the course of desalinazation. It was suggrsted that the crop species belonging to Fabaceae, a sensitive family to soil salinity, must be cultivated when the soil salinity decreased below 10ds/m. To know the critical salinity level for crop growth,salinity of saline soil collected from reclaimed tidal land was adjusted from 10.0ds/m tp41.7ds/m with tap water. It was suggested that the ECs of the soil in which the plant height of each crop spicies was reduced to 50% of control plant were 22.6 and 21.7 ds/m in rice, barley, corn, mung bean, and soy bean,respectively.

• Korean Journal of Ecology and Environment
• /
• v.37 no.2 s.107
• /
• pp.248-254
• /
• 2004

This study was conducted to investigate the effects of salinity in irrigation water on the growth, yield components, yield and grain quality of rice plant by the pot experiments. Irrigation waters were supplied with control and amended with NaCl at 1,000, 2,000, 3,000, 5,000, and 7,000 ${\mu}s\;cm^{-1}$ electrical conductivity. A randomized block design was used with four replicates for each treatment and control. As increasing salt concentration, plant height, tiller number, SPAD value, dry weight, content of N, P, and K, ripened grain ratio (%), 1,000 grain weight, and protein content (%) tended to decrease, especially, significant at 3,000 ${\mu}s\;cm^{-1}$ of salt level. Grain yield decreased significantly at all treatments. The percentage of head rice slightly tended to increase as the salt concentration due to the decrease of green kernel. The percentage of green kernel was significantly lower at 3,000 ${\mu}s\;cm^{-1}$ of salt level than the control.