• Title/Summary/Keyword: tide

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Statistical analyses on the relationships between red tide formation and meteorological factors in the Korean Coastal Waters and Satellite monitoring for red tide (한국 연안의 적조형성과 기상용인간의 상관성에 대한 통계학적 해석 및 위성에 의한 적조모니터링)

  • Yoon Hong-Joo;Lee Moon-Ok;Ryu Cheong-Ro
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.279-284
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    • 2004
  • Red tide(harmful algae) in the Korean Coastal Waters has a given a great damage to the fishery every year. However, the aim of our study understands the influence of meteorological factors (air and water tempaerature, precipitation, sunshine, solar radiation, winds) relating to the mechanism of red tide occurrence and monitors red tide by satellite remote sensing, and analyzes the potential area for red tide occurrence by GIS. The meteorological factors have directly influenced on red tide formation. Thus, We want to predict and apply to red tide formation from statistical analyses on the relationships between red tide formation and meteorological factors. In future, it should be realized the near real time monitoring for red tide by the development of remote sensing technique and the construction of integrated model by the red tide information management system (the data base of red tide - meteorological informations).

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Enhancing Red Tides Prediction using Fuzzy Reasoning and Naive Bayes Classifier (나이브베이스 분류자와 퍼지 추론을 이용한 적조 발생 예측의 성능향상)

  • Park, Sun;Lee, Seong-Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.9
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    • pp.1881-1888
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    • 2011
  • Red tide is a natural phenomenon to bloom harmful algal, which fish and shellfish die en masse. Red tide damage with respect to sea farming has been occurred each year. Red tide damage can be minimized by means of prediction of red tide blooms. Red tide prediction using naive bayes classifier can be achieve good prediction results. The result of naive bayes method only determine red tide blooms, whereas the method can not know how increasing of red tide algae density. In this paper, we proposed the red tide blooms prediction method using fuzzy reasoning and naive bayes classifier. The proposed method can enhance the precision of red tide prediction and forecast the increasing density of red tide algae.

Study on a GIS Database of Red Tide Information System (적조정보시스템의 GIS데이터베이스화 연구)

  • Jeong Jong-chul
    • Spatial Information Research
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    • v.12 no.3
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    • pp.263-274
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    • 2004
  • The purpose of this study is to develop of red tide information system for spatial and temporal analysis of red tide including the outbreak season of red tide and biological-oceanography parameters using GIS techniques. The outbreaks of red tide were sporadic in the South Sea until 1994, but became frequent and widespread in whole coastal waters of the South Sea and East Sea since 1995. Therefore, the research fields of red tide has undergone a major changes. For monitoring of red tide, many kinds of techniques were carried out such as remote sensing, GIS and fuzzy model system. In this research, the development methods of red tide information system were suggested. For construction of the CIS based Red Tide database, spatial distribution area, species of red tide plankton and physical environment were analyzed.

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Tide and tidal current around the sea route of Jinhae and Masan passages (진해 및 마산항로 주변해역의 조석·조류특성)

  • CHOO, Hyo-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.1
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    • pp.45-56
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    • 2021
  • In order to understand the tide and current around the sea route of Jinhae and Masan passages, tide measurement and 2D numerical model experiments of tidal current and residual flow were carried out. Tide is composed of 84% of semi-diurnal tide, 11% of diurnal tide and 4% of shallow water tide, respectively. Phase lags of the major components for the tide around the study area have little differences. The flows are reversing on the whole, but have rotational form around Jamdo Island, south of Masan passage in spring tide and Ungdo Island, north of Masan passage in middle and neap tide. Current flows the speed of 50 cm/s in the sea areas near small islands, 5 cm/s in Jinhae harbor, Hangam bay and near Jinhae industrial complex and 20-30 cm/s in Jinhae passage, Budo channel and Masan passage. Tide-induced topographical eddies are formed near small islands, but few eddies exist and the flow rate of less than 5 cm/s tidal residual current formed in Jinhae and Masan passages. The flows in Jinhae and Masan passage give a good condition for a passage into Jinhae and Masan harbor.

Statistical Analyses on the Relationships between Red Tide Formation and Meteorological Factors in the Korean Coasts, and Satellite Monitoring for Red Tide (한국 연안에서의 적조형성과 기상인자간의 상관성에 대한 통계학적 해석 및 위성에 의한 적조 모니터링)

  • Yoon, Hong-Joo;Kim, Hyung-Seok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.2
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    • pp.140-146
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    • 2005
  • The aim of our study understands the influence of meteorological factors relating to the formation of the red tide, and monitors the red tide by satellite remote sensing. The meteorological factors have directly influenced on red tide formation. Thus, it was possible to predict and apply to red tide formation from statistical analyses on the realtionships between red tide formation and meteorological factors, and also to realize the near real time monitoring for red tide by satellite remote sensing.

Red Tide Prediction using Neural Network and SVM (신경망과 SVM을 이용한 적조 발생 예측)

  • Park, Sun;Kim, Kyung-Jun;Lee, Jin-Seok;Lee, Seong-Ro
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.5
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    • pp.39-45
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    • 2011
  • There have been many studies on red tide because of increasing of damage to sea farming by a red tide blooms of harmful algae. The studies of red tide have mostly focused chemical properties and investigation of biological cause. If we can predict the occurrence of red tide, we will be able to minimize the damage of red tide. However, internal study of prediction of red tide blooms is only classification method that is still insufficient for red tide blooms forecast. In this paper, we proposed the red tide blooms prediction method using neural network and SVM.

Tidal and Seasonal Variations of Nutrients in Keunso Bay, the Yellow Sea (서해 근소만에서 영양염의 조석 및 계절 변화)

  • Kim, Dong-Seon;Kim, Kyung-Hee
    • Ocean and Polar Research
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    • v.30 no.1
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    • pp.1-10
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    • 2008
  • In order to find the effect of intertidal sediments on nutrient cycle in coastal environment, we measured ammonia, nitrate, phosphate, and silicate concentrations every hour during at least 12 hours in the entrance of Keunso Bay during four seasons. The content of ammonia and silicate do not change considerably with season, but nitrate shows large seasonal variation. In summer, nitrate concentration was much lower than in other seasons, which resulted from large biological uptake and active denitrification in intertidal sediments during summer. Phosphate also exhibit seasonal variations, but not that large like nitrate. N/P and N/Si ratios were lower in summer than in other seasons, which was due to active denitrification in the intertidal sediments during summer. For all seasons, ammonia concentrations were higher at low tide than at high tide, but nitrate concentrations were higher at high tide. Dissolved inorganic nitrogen concentrations measured in spring, summer, and winter were higher at high tide than at low tide, but in fall, they were higher at low tide than at high tide. For spring and winter, phosphate and silicate concentrations were higher at low tide than at high tide, while in summer and fall, they were higher at high tide than at low tide. In Keunso Bay, intertidal sediments affect significantly the nutrient cycle around the coastal areas. The intertidal sediments act as a source for ammonia and silicate, but as a sink for nitrate. However, phosphate is not considerably influenced by intertidal sediments.

Environmental Factors and Catch Fluctuation of Set Net Grounds in the Coastal Waters of Yeosu - 2 . Sea Water Circulation in the Vicinity of Set Net Ground - (여수연안 정치망어장의 환경요인과 어황 변동에 관한 연구 - 2 . 어장주변 해역의 해수유동 -)

  • Kim, Dong-Soo;Rho, Hong-Kil
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.30 no.3
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    • pp.142-149
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    • 1994
  • In order to investigate the environmental properties of set net grounds located in the coastal waters of Yeosu. The current in the vicinity of set net grounds was observed by drogue and current meter in 1990 and 1992. The results obtained are summarized as follows: The direction of tidal current at the north enterance of Yeosu bay was southerly in ebb and northwesterly in flood without the distiction of the neap tide and the spring tide. In spring tide the maximum Velocity of the tidal current was 68 cm/sec in ebb and 66 cm/sec in flood. In neap tide the maximum velocity of the tidal current was 37 cm/sec in ebb and 35 cm/sec in flood. And so the direction of residual current was the south ward mainly and 21 cm/sec. The direction of tidal current at set net fishing grounds was southwesterly in ebb and westerly or northwesterly in flood. Regardless of the distinction of neap and spring. The maximum velocity of the current in spring tide was 50 cm/sec in ebb and 40 cm/sec in flood and that in neap was 28 cm/sec in ebb and 25 cm/sec in flood. In spring tide the speed vector along the major axis of semidiurnal tide component was three times as large as diurnal tide. In neap tide, however, the speed vector was about 50% less then that in spring tide, and the semidiurnal tide and diurnal tide were equal in the size of current ellipse and the direction of major axis. The sea area had a southwesterly residual current. 11 cm/sec in spring tide and 7 cm/sec in neap tide. According to the result of drogue tracking, the vicinity of set net fishing ground had a southerly residual current which formed in Yeosu Bay and a weak westerly residual current toward Dolsando from Namhedo. Therefore, set net fishing ground in coastal water of Yeosu was distributed in boundary of inner water which formed from Seamjin river and offshore water supplied from the vicinity of Sorido and Yochido.

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A Study on the Spatial Determination of Red Tide Occurrence Area Using GSIS (GSIS 이용한 적조발생지의 공간결정 연구)

  • Kim, Jin-Gi
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.2 s.40
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    • pp.51-57
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    • 2007
  • Few researches related to the spatial determination of areas where red tide occurs have been performed, so accurately determining the area where red tide occurs and disappears poses difficulties. Therefore, a more objective and scientific method is necessary to analyze the occurrence and movement of red tide based on a geo-spatial information system. In this study, the coastline was extracted using a digital topographic map in order to examine areas where red tide occurs each year. An analysis of red tide occurrence areas, which were determined based on red tide data for the last several years, showed that only Yeoja bay had almost a zero case of red tide of the areas studied, whereas Dolsando in the South Sea and NamHaedo Aenggang bay areas exhibited the highest frequency of red tide occurrences. Based on these results, by using a system that determines the geo-spatial distribution status of areas repeatedly hit by red tide every year, it would be possible to predict the course of red tide and prevent consequent damages.

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Effective sampling of estuarine fauna by a passive net in theWest Sea of Korea occurring strong tide (조류가 강한 서해 하구에서 수동어구를 이용한 하구역 유영생물의 효율적 채집)

  • Hwang, Sun-Do;Im, Yang-Jae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.338-343
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    • 2011
  • To obtain the effective sampling estuarine fauna by a passive net in the West Sea of Korea occurring strong tide, catch were collected by bag nets with various sampling trials off Ganghwa Island in November 2009. We compared the difference of community structures (on spring tide vs. neap tide, total sample vs. subsample and 4 nets vs. 1 net) with each species composition as a sampling unit by the Pearson chi-square test. Number of individual at the spring tide was more abundant than that at the neap tide (p<0.0001) although number of species at the spring tide was not significantly different with that at the neap tide (p=0.174). Both number of species (p=0.138) and number of individual (p=0.096) were not significantly different between total sample and random subsample. Number of species was not significantly different between the subsample by 1 net and the subsample by 4 nets (p=0.515), but number of individual was a little different on both samples (p=0.024). In conclusion, we suggest the subsample by 1 net at spring tide as the effective sampling estuarine fauna by a passive net in the West Sea occurring strong tide.