• Proceedings of KOSOMES biannual meeting
• /
• 2007.11a
• /
• pp.1-7
• /
• 2007

To illustrate the variation of oceanic condition around artificial upwelling structure which is located in the South Sea of Korea, cm observations were carried out on December, 2005, April, August and October, 2006. Temperature, salinity and density(sigma-t) was nearly homogeneous through the whole depth by mixing of the seawater in winter. Stratification was not clear in spring, and it was only formed weakly in the surface layer shallower than 10m. Stratification was formed about $10{\sim}20$ m depth in summer and about $30{\sim}40$ m depth in autumn. Vertical gradient of temperature was larger than that in the part of western area along the artificial seamount in summer and autumn. The variation of stratification was also occurred around near the artificial structure area after set up structure.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2006.11a
• /
• pp.290-293
• /
• 2006

From the hydraulic experiment, it was concluded that upwelling could be enhanced when the relative structure height (the ratio of structure height to water depth) was 0.3 and stratification parameter was 3.0. In addition, the optimum size of rubbers was determined that the effect of the mean horizontal length of block was affected incident velocity than size of block. In the numerical experiment, the relation between the shape of rubber and stratification parameter was verified, ana the hydraulic characteristics of 3-D flow field around the artificial structures were investigated. Phenomena of flow field around the artificial upwelling structures corresponded with the results of hydraulic experiment. The position with maximum velocity in artificial upwelling structure was the center of top of its front side and the slip stream occurred at the inside and behind-bottom of artificial upwelling structures. The velocity of slip stream and early amplitude of velocity were higher in the inside than the behind-bottom.

• Proceedings of KOSOMES biannual meeting
• /
• 2007.11a
• /
• pp.9-14
• /
• 2007

To illusσ'ate the variation of current around artificial upwelling structure which is located in the South sea of Korea, current measurements using ADCP (Acoustic Doppler Current Profiler) during neap and spring tides were carried out on 27th July(summer)， 14th October and 30th November(Autumn), 2006. Current after the set up of artificial upwelling structure were shown different in the upper and lower layer, the boundary between the upper and lower layer was at $27{\sim}30m$ depth in summer. And the boundary layer was formed structure of three layer in Autumn. Upwelling and downwelling flow were occurred around the seamount， and these vertical flows were connected from surface to bottom The distribution of vertical shear and relative vorticity support the vertical flow around the seamount. The strength of vertical shear was higher and the direction of relative vorticity was anticlockwise (+) around the upwelling area.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.27 no.6
• /
• pp.419-423
• /
• 2015

The flowing caused by artificial upwelling structure occurs ascending water flowing and vortex of rear side. In this moment, plentiful nutrient in the bottom water moves to the surface of the water and makes those plankton and fishing ecology promoted so that the fishing productivity can be enhanced. In this study, the changes of the upwelling flowing is included in consideration of the conditions of stratification by using CFD. In the conclusion, the closer upwelling effect is from the artificial upwelling structure, the better effectiveness comes out. Regardless of the conditions of stratification, only the upwelling feature from the bottom to the surface was shown up. But considering the conditions of stratification, the repeated flowing feature between upwelling and downwelling was verified.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.12 no.4 s.27
• /
• pp.301-306
• /
• 2006

In order to estimate the characteristics of water movements around artificial upwelling structure, current measurements were carried out along lines E-W and S-N on May 4th(neap tide} and May 30th(spring tide), 2006. In the study area, southeastward flow was dominant during the field observations, and the pattern of water movement in the upper layer above 30m depth was different from that in the lower layer below 30m depth Vertical flow(w-component} around the artificial structure area and western area was shown to be upward flow, but downward flow occurred in the southern, northern and eastern parts at the neap tide. At the spring tide, the ebb current along E-W line showed upwelling flow in the eastern part and western area and showed upwelling flow near the artificial structure area and downwelling flow far away that one. At the spring tide, upward flow was dominant along S-N line during the flood current Volume transport by upward flow was higher than that by downward flow. Volume transport by upward flow during ebb of neap tide was greater than during flood current of neap tide, but was reverse at the spring tide.

• Journal of Ocean Engineering and Technology
• /
• v.21 no.4
• /
• pp.21-27
• /
• 2007

The multiplication equipment of marine products with artificial upwelling structures could be useful in the fishing grounds near coastal areas. Artificial upwelling structures could move the inorganic nutrients from the bottom to the surface. Artificial upwelling structures have been used to improve the productivity of fishing grounds. Until now, research on artificial upwelling structures has been related to the distribution of the upwelling region, upwelling structures, and the marine environment. However, little work on the optimum design of the rubber-mound artificial upwelling structures has been done to increase the efficiency of drawing up the inorganic nutrients. This study investigated the optimum cross-section of rubber-mound artificial upwelling structures by means of hydraulic experiments. The hydraulic experiments include the falling test of rubber. Based on the results of the falling test, the relationship between the length of the rubber mound and water velocity, and the relationship between the shape of the rubber and the stratification parameter were established. In addition, the effect of the void ratio of various artificial structures on the stratification parameter was studied. From the experiment, it was found that upwelling could be enhanced when the ratio of structure height to water depth was 0.3 and stratification parameter was 3.0. The upwelling was not improved when the void ratio exceeded 0.43. The optimum size of rubber mounds was determined when the incident velocity was influenced by the mean horizontal length rather than size of block.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2003.05a
• /
• pp.132-133
• /
• 2003

배타적 경제수역 및 UN 해양법 발효 등 조업 가능한 어장의 급속한 축소와 더불어 자국의 연안역 개발에 대한 중요성이 크게 부각되고 있다. 이에 따라 인위적인 수산자원 조성방법을 통하여 연안의 생산성을 향상시키고자 하는 노력의 일환으로 최근에는 해저면에 인공 구조물을 설치하여 국지적인 인공용승을 발생시키려는 연구가 시도되고 있다. (중략)

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.2
• /
• pp.187-192
• /
• 2003

To evaluate the oceanographic conditions for the artificial upwelling we measured vertical stratification coefficients, current speed distribution and grain size distribution of bottom sediment in the vicinity of Gukdo and Somaemuldo near Geojedo. There were a strong stratification between surface and bottom layers in summer, the stratification was weak from autumn to winter, and the water was well mixed during winter. In summer nutrient concentration of the bottom layer was 4 times higher than that of the surface layer. Underwater currents were strong in the bottom layer. We conclude that the oceanographic conditions in the area will meet the basic requirement for the construction of artificial upwelling.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.2
• /
• pp.118-125
• /
• 2012

World population has increased rapidly following the industrial revolution, reaching 7 billion in 2012. Several forecasts estimate that this number will rise to about 8 billion in 2025. Improvements of living standards in developing nations have also raised resource and energy demands worldwide. In consequences, human beings have faced many global and urgent problems, such as global warming, water and food shortages, resource and energy crises, and so on. Many ocean utilization technologies for avoiding or reducing such big problems have been developed, for examples $CO_2$ ocean sequestration, seawater desalination, artificial upwelling, deepwater mining, and ocean energies. It is important, however, to assess such technologies from the viewpoints of sustainability and public acceptancy, since the aims of those technologies are to develop sustainable social systems rather than conventional ones based on fossil resources. Inclusive Marine Pressure Assessment and Classification Technology Research Committee (generally called IMPACT Research Committee) of Japan Society of Naval Architects and Ocean Engineers, has proposed Inclusive Impact Index "Triple I" as an indicator, which can predict both environmental sustainability and economical feasibility, in order to assess the ocean utilization technologies from the viewpoints of sustainability and public acceptancy. This index was considered by combining Ecological Footprint and Environmental Risk Assessment. The Ecological Footprint and the Environmental Risk Assessment are introduced in the first part of this paper. Then the concept and the structure of the Triple I are explained in the second part of this paper. Finally, the economy-ecology conversion factor in Triple I accounting is considered.