• 제목/요약/키워드: Oceanographic factors

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Estimation of potential area for red tide occurrence in the Korean coasts by Marine GIS

  • Yoon, Hong-Joo;Whang, Wha-Jeung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.876-878
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    • 2003
  • It was studied on the choice of potential area for red tide occurrence from oceanographic factors. Oceanographic factors of favorable marine environmental conditions for the red tide formation included warm water temperature, low salinity, high suspended solid, low phosphorus, low nitrogen. It was founded the potential areas for red tide occurrence in August 2000 by GIS conception: Yeosu~Dolsan coast, Gamak bay, Namhae coast, Marado coast, Goheung coast, Deukryang bay, respectively.

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기후 및 해양 요인과 김 생산량과의 관계에 관한 연구 (The Relationship between Climatic and Oceanographic Factors and Laver Aquaculture Production)

  • 김도훈
    • 수산경영론집
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    • 제44권3호
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    • pp.77-84
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    • 2013
  • While some steps in laver aquaculture production can be controlled artificially to a certain extent, the culturing process is largely affected by natural factors, such as the characteristics of seawater, climatic and oceanographic conditions, etc. This study aims to find a direct relationship between climatic and oceanographic factors (water temperature, air temperature, salinity, rainfall, sunshine duration and wind speed) and laver aquaculture production in Wando region, the biggest aquaculture production area of laver, located in the southwest coast of Korea using a multiple regression analysis. Despite the small sample size of a dependent variable, the goodness of model fit appeared acceptable. In addition, the R-squared value was 0.951, which means that the variables were very explanatory. Model results indicated that duration of sunshine, temperature, and rainfall during the farming period from the end of September to the end of April would be important factors affecting significantly to the laver aquaculture production.

원격탐사를 이용한 한국 남해 중부해역에서의 적조 예찰 연구 II. 적조발생과 해양인자간의 상관성 연구 (Study on monitoring and prediction for the red tide occurrence in the middle coastal area in the South Sea of Korea II. The relationship between the red tide occurrence and the oceanographic factors)

  • 윤홍주;남광우;조한근;변혜경
    • 한국정보통신학회논문지
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    • 제8권4호
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    • pp.938-945
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    • 2004
  • 남해 중부해역에서 적조발생과 관련해서 적조 다발월인 여름과 초가을에 기온과 마찬가지로 높은 수온을 유지한다. 또한 많은 강수량에 의하여 부유물질 및 영양염류가 증가하고 염분이 대체로 떨어지는 것을 알 수 있었다. 이때 적조의 bloom으로 인하여 대표적인 영양염류인 질소와 인의 값이 떨어진다. 그리고 적조생물의 사후 미생물 분해 작용이 활발하여 산소의 소모가 증가하여 용존산소가 급격히 떨어지고 화학적산소요구량이 높게 나타나는 것을 알 수 있었다. 이때 식물성플랑크톤의 성장 제한인자로 작용하는 부유물질, 인산염, 질산염의 공간분포도를 이용해서 적조발생의 잠재력을 지닌 최적지를 결정하였는데, 최적지로서는 여수∼돌산해역, 가막만 북부지역, 남해 일부해역, 나로도해역, 고흥 남부의 일부 연안, 득량만과 인접한 고흥 서부 해역이었다.

Satellite Monitoring and Prediction for the Occurrence of the Red Tide in the Middle Coastal Area in the South Sea of Korea

  • Yoon, Hong-Joo;Kim, Young-Seup
    • 대한원격탐사학회지
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    • 제19권1호
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    • pp.21-30
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    • 2003
  • It was studied the relationship between the red tide occurrence and the meteorological and oceanographic factors, the choice of potential area for red tide occurrence, and the satellite monitoring for red tide. From 1990 through 2001, the red tide continuously appeared and the number of red tide occurrence increased every year. Then, the red tide bloomed during the periods of July and August. An important meteorological factor governing the mechanisms of the increasing in number of red tide occurrence was heavy precipitation. Oceanographic factors of favorable marine environmental conditions for the red tide formation included warm water temperature, low salinity, high suspended solid, low phosphorus, low nitrogen. A common condition for the red tide occurrence was heavy precipitation 2∼4 days earlier, and the favorable conditions for the red tide formation were high air temperature, proper sunshine and light winds for the day in red tide occurrence. From satellite images, it was possible to monitor the spatial distributions and concentrations of red tide. It was founded the potential areas for red tide occurrence in August 2000 by CIS conception: Yeosu∼Dolsan coast, Gamak bay, Namhae coast, Marado coast, Goheung coast, Deukryang bay, respectively.

한국연근해 참조기 (Pseudosciaena polyactis Bleeker) 어장의 해황 특성 (Oceanographic Conditions of Eishing Ground of Yellow Croaker (Pseudosciaena polyactis) in Korean Waters)

  • 백철인;조규대;이충일;최광호
    • 한국수산과학회지
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    • 제37권3호
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    • pp.232-248
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    • 2004
  • In order to utilize fisheries resources under a joint management scheme with adjacent nations, as well as detecting of fishing grounds, the factors which influence yellow croaker (Pseudosciaena polyactis) in Korean waters were studied using historical catch per unit effort and oceanographic data. The main fishing ground near Cheju Island was located along the thermal front formed between the Yellow Sea Bottom Cold Water (YSBCW) and northward moving warm current. When the YSBCW (index temperature: $10^{\circ}C)$ strongly extended southward, the fishing condition were worse than average. Especially, low temperatures greatly influenced stow net fisheries, which were operated in the deep water layer The concentration and dispersal of fishing ground and catch coincided with oceanographic features and the seasonality of water masses.

부산연안 미역(Undaria pinnatifida)양식 생산 예측을 위한 장기 해양자료 분석 (Analysis of Long-term Oceanic Data for the Prediction of Undaria pinnatifida Aquaculture Production off the Coast of Busan)

  • 한인성;서영상;이준수
    • 한국수산과학회지
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    • 제46권6호
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    • pp.941-947
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    • 2013
  • To understand the relationship between various oceanographic factors and seaweed production, we examined the annual accumulated aquaculture production of Undaria pinnatifida with respect to water temperature, salinity, dissolved oxygen, current patterns and nutrients over 21 years (1990-2010) (this date range does not add up to over 21 years) along the coast of Busan, Korea. According to the results of the cross-correlation function, annual production of U. pinnatifida was closely related to the following conditions: low water temperature, low salinity, strong Tsushima Warm Current, and high concentrations of dissolved oxygen and nutrients. In this study, we also considered the Index of Oceanographic factors for U. pinnatifida (IOU) by computation of a simple equation. This index will be used for the prediction of U. pinnatifida aquaculture production off the coast of Busan.

A Rendezvous Node Selection and Routing Algorithm for Mobile Wireless Sensor Network

  • Hu, Yifan;Zheng, Yi;Wu, Xiaoming;Liu, Hailin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권10호
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    • pp.4738-4753
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    • 2018
  • Efficient rendezvous node selection and routing algorithm (RNSRA) for wireless sensor networks with mobile sink that visits rendezvous node to gather data from sensor nodes is proposed. In order to plan an optimal moving tour for mobile sink and avoid energy hole problem, we develop the RNSRA to find optimal rendezvous nodes (RN) for the mobile sink to visit. The RNSRA can select the set of RNs to act as store points for the mobile sink, and search for the optimal multi-hop path between source nodes and rendezvous node, so that the rendezvous node could gather information from sensor nodes periodically. Fitness function with several factors is calculated to find suitable RNs from sensor nodes, and the artificial bee colony optimization algorithm (ABC) is used to optimize the selection of optimal multi-hop path, in order to forward data to the nearest RN. Therefore the energy consumption of sensor nodes is minimized and balanced. Our method is validated by extensive simulations and illustrates the novel capability for maintaining the network robustness against sink moving problem, the results show that the RNSRA could reduce energy consumption by 6% and increase network lifetime by 5% as comparing with several existing algorithms.

태평양 수역 우리나라 다랑어선망어업의 조업 특성 및 해양환경에 따른 어장 변동 (Changes in fishing characteristics and distributions of Korean tuna purse seine fishery by oceanographic conditions in the Pacific Ocean)

  • 이미경;이성일;이춘우;김장근;구정은
    • 수산해양기술연구
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    • 제52권2호
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    • pp.149-161
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    • 2016
  • Fishing characteristics of Korean tuna purse seine fishery in the Pacific Ocean were investigated using logbook data compiled from captain onboard and the statistical data from 1980 to 2014. Changes in fishing ground and correlation between marine environmental factors and fishing patterns were investigated using Oceanographic index. The proportion of unassociated set was higher than that of associated set. The catch proportion of yellowfin was higher in the unassociated set, while that of skipjack and bigeye was higher in the associated set. Due to vessels, fishing gears and Korean captains' high-level of skills in fishing technology optimized for the unassociated set and preference of large fishes, especially large yellowfin tuna, it showed unique fishing characteristics focusing on the unassociated set. As for fishing distributions of Korean tuna purse seine fishery and impacts of oceanographic conditions on the fishery, the main fishing ground was concentrated on the area of $5^{\circ}N{\sim}10^{\circ}S$, $140^{\circ}E{\sim}180^{\circ}$ through the decades. When stronger El-nino occurred, the range of fishing ground tended to expand and main fishing ground moved to the eastern part of western and central Pacific Ocean. During this season, yellowfin tuna had high CPUE and catch proportion of yellowfin tuna in the eastern part also increased. As for the proportion of fishing effort by set type, proportion of log associated set was high during El-nino season while that of FAD associated set was high during La-nina season.

Oceanographic indicators for the occurrence of anchovy eggs inferred from generalized additive models

  • Kim, Jin Yeong;Lee, Jae Bong;Suh, Young-Sang
    • Fisheries and Aquatic Sciences
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    • 제23권7호
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    • pp.19.1-19.14
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    • 2020
  • Three generalized additive models were applied to the distribution of anchovy eggs and oceanographic factors to determine the occurrence of anchovy spawning grounds in Korean waters and to identify the indicators of their occurrence using survey data from the spring and summer of 1985, 1995, and 2002. Binomial and Gaussian types of generalized additive models (GAM) and quantile generalized additive models (QGAM) revealed that egg density was influenced mostly by ocean temperature and salinity in spring, and the vertical structure of temperature, salinity, dissolved oxygen, and zooplankton biomass during summer in the upper quantiles of egg density. The GAM and QGAM model deviance explained 18.5-63.2% of the egg distribution in summer in the East and West Sea. For the principle component analysis-based GAMs, the variance explained by the final regression model was 27.3-67.0%, higher than the regular models and QGAMs for egg density in the East and West Sea. By analyzing the distribution of anchovy eggs off the Korean coast, our results revealed the optimal temperature and salinity conditions, in addition to high production and high vertical mixing, as the key indicators of the major spawning grounds of anchovies.