• Journal of the Korean association of regional geographers
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• v.13 no.4
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• pp.422-437
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• 2007

Dokdo has historical and political meaning in relation to the territorial problems with Japan. The area can be the main factor to explain the formation and development process of East-Sea as exposure volcanic island at East-Sea with Ulreong-island. Accordingly, it also has an important meaning of physical geography aspects In this research, it is perceived the geomorphological development process of slope due to the salt weathering which is considered as the most important factor to understand whole geomorphology of Dokdo. And researched how a geomorphology of this sort affects to animal and plants. The peculiar geomorphology is tafoni which is a weathering geomorphology and one of the remarkable geomorphology in preservation of Dokdo. Tafoni at west part of Dongdo is distributed intensively near shoreline which is composed tuff. The shape of tafoni is mainly massive, circle and oval in Massive tuff breccia layer also is formed toward horizontality bedding direction in Bedded lapilli tuff. Tafoni in Dokdo is constituted after middle of Holocene. This fact can be proved by ranging at surface of sea-cliff which is formed wave erosion after middle of Holocene sea-level reaching to present level. Tafoni is also the most contribute factor of geomorphology dissection of Dokdo as it is eroded the bed rock with salt weathering. In bottom part of tafoni it has an important function for habitat of birds. Herbaceous plants are on it. To procrastinate of bed rock dissection by growth of Tafoni, conservation of vegetation and soil are most important factor.

• Journal of Ecology and Environment
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• v.41 no.3
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• pp.45-53
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• 2017

Background: There have been many studies on the growth conditions of Zostera marina and Zostera japonica, but few studies have examined how spatial and temporal factors affect growth in established seagrass beds or the distribution range and shoot density. This study aims to clarify the factors that determine the temporal and spatial distribution of Zostera marina and Zostera japonica in the Seto Inland Sea east of Yamaguchi Prefecture. Methods: The study site is in Hiroshima Bay of the Seto Inland Sea, along the east coast of Yamaguchi Prefecture, Japan. We monitored by diving observation to confirm shoot density, presence or absence of both species and observed water temperature, salinity by sensor in study sites. Results: The frequency of occurrence of Zostera marina was high in all seasons, even in water depths of D.L. + 1 to -5 m ($80{\pm}34%$ to $89{\pm}19%$; mean ${\pm}$ standard deviation), but lower (as low as $43{\pm}34%$) near the breakwall, where datum level was 1 to 2 m, and it was further reduced in datum level -5 m and deeper. The frequency of occurrence of Zostera japonica was highest in water with a datum level of +1 to 0 m. However, in datum level of 0 m or deeper, it became lower as the water depth became deeper. Datum level +1 m to 0 m was an optimal water depth for both species. The frequency of occurrence and the shoot density of both species showed no negative correlation. In 2011, the daily mean water temperature was $10^{\circ}C$ or less on more days than in other years and the feeding damage by S. fuscescens in the study sites caused damage at the tips. Conclusions: We considered that the relationship between these species at the optimal water depth was not competitive, but due to differences in spatial distribution, Zostera marina and Zostera japonica do not influence each other due to temperature conditions and feeding damage and other environmental conditions. Zostera japonica required light intensity than Zostera marina, and the water depth played an important role in the distribution of both species.

• Journal of fish pathology
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• v.20 no.3
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• pp.211-220
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• 2007

Red sea bream iridovirus disease (RSIVD) cause massive economic losses in marine aquaculture industry in Korea. The causative agent of this disease (RSIV) infects a wide range of fish species. The aims of this study were to monitor RSIV in wild marine fishes and to give critical information for controling the disease through prophylactic methods. Prevalence of the viral disease, geological distribution and reservoir of the virus were investigated using wild marine fishes captured in southern coast and east china sea for two years. (Polymerase Chain Reaction) PCR results showed that RSIV were detected in 39 (24.3%) out of 160 fish. MCP gene sequences of viral strains isolated in this study were closely related to that of a reference strain, red seabream-K, belonging to Megalocytivirus subgroup Ⅲ. The results suggest that some of wild marine fishes are RSIV carriers and may spread the pathogen directly to fish farmed in coastal area.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.91-105
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• 2013

This study performed an assessment of wave power potential in the Kangwon and Dongnam regions encompassing the East Sea and part of South Sea. Annual electricity production and economic effects of 28 wave energy converters with 750kW capacity were analyzed using significant wave height and peak wave period data(created from the NOAA's NWW3 model) and InVEST software(developed by Stanford University and University of Minnesota). Annual electricity production was estimated to be up to 1,207MWh/year and at least 163MWh/year. The spatial pattern of annual electricity production showed that the sea far from land has higher wave power potential than the sea near coast. The net present value(NPV) of 28 wave energy converters was calculated by considering an operation period of 25 years. When assuming that the electricity produced from wave energy converters is transferred to onshore power plants through underwater cables, the NPV was estimated to be up to 5,883USD(6,600,000KRW) and at least -63,494USD(-71,000,000KRW). In contrast, the NPV increased up to 28,095 USD(31,600,000KRW) when assuming that the electricity is utilized in the Ulleungdo and Dokdo. In addition, it was found that the break-even line of NPV in the East Sea becomes closer towards the land according to the increment of electricity price. The NPV of wave energy converters near the Ulleungdo and Dokdo will be 88,158 USD(99,000,000KRW) if the increment of electricity price is 100KRW.

• Journal of the Korean Geographical Society
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• v.38 no.2
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• pp.156-172
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• 2003

In this paper we identify that there are High Higher surfaces(HH-surface) around Jeongdongjin and Daejin area where Higher surfaces(H-surface) of marine terrace are formed on a large scale. On the basis of an altitude of the ancient shoreline of the marine terraces, geomorphic surfaces can be classified into HH I (140m a.s.l), HH II (110m a.s.l), H I (90m a.s.l), H II (70m a.s.l), M (40m a.s.l), L I (25m a.s.l) and L II (10m a.s.l). Besides, we identify that the lowest surfaces(5~6m a.s.l) are found extensively in the research area which are assumed to be formed in the Holocene. Considering that the formation mechanism of the marine terraces in the research area is similar to that of the marine terraces at both Campo area in the south east coastal region of Korea md the thalassostatic terraces of Osip River in Samchuk in a short distance from the research area, we can assume that the HH-surfaces in both areas were formed in the same period. Based on the fact that L I- surface was formed on the Last Interglacial Stage of MIS 5, we can infer that M- was formed in MIS 7, H I- in MIS 9, H II- in MIS 11, HH I- in MIS 13 and HH II- in MIS 15. The reason for that H-surfaces, similar to those at Gampo area, to remain on a large scale is that the Holsteinian Interglacial continued for a long period of time and at that time there was a large wave-cut platform in the vicinity of the shoreline.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.684-692
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• 2007

The object of this study is to identify the factors that is making and promoting cooperation for the unified forest fire administration, and then introduce cooperation process and cooperation manual for an effective forest management. For this purpose, the case studies were carried about "The East Coastal Forest Fire Administration Center" and "The Forest Fire Administration Center in Mt. Jiri Area" to have obtained excellent results by cooperation among administrative districts, and cooperative factors were extracted through analyzing each steps. That is, cooperation steps were divided into 4 steps of Initiation, Planning, Implementation, Benefiting, and in-depth interview and questionnaires were carried for extracting cooperation factors by each step for the unified cooperative forest management system. And with AHP analysis, essential four factors were extracted by each step based on priority order. Finally with the base of the essential 4 factors by each step, the cooperation process and manual appliable to forestry cooperation project were developed. This will be a guideline in order to achieve successful forest administrations through the cooperation among local administrative governments.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.14-20
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• 2015

Coastal plant species, Plantago camtschatica Cham. native to the coastal region of the East Sea were sampled and then morphologically different 20 endophytic fungal strains were purely isolated. Phylogenetic analysis of isolates was done by the Bayesian program based on sequenced internal transcribed spacer (ITS-rDNA) region. Culture filtrates of each of 20 isolates were treated to Waito-c rice (WR) seedlings for verifying plant growth-promoting activity, respectively. As the results, E/PC/10/1 strain showed the highest plant growth-promoting activity among them. The culture filtrate of the strain E/PC/10/1 was revealed as containing gibberellins ($GA_1$, $GA_3$, $GA_4$) by using HPLC, and gas GC/MS with selected ion monitoring (SIM). Finally, this strain was identified as novel Penicillium spinulosum species that producing new GAs with microscopic observation and further molecular analysis with beta-tubulin gene sequence.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.213-223
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• 2011

The status and changes of water quality of national fishing harbors and designated ports in East Coast of Korea were analyzed to support establishment effective water environmental management. COD (Chemical Oxygen Demand) concentration was satisfied to designated water quality criteria in most areas, but TN (Total Nitrogen) and TP (Total Phosphorus) exceeded the criteria frequently. Also, peak concentration was summer in COD and SS (Suspended Solid), but winter in TP. Eutrophication index of Ganggu and Pohang (old) area were the highest. Pollution index by function of COD, TN, and TP of Ganggu, Pohang, Jumunjin, and Guryongpo was high with gradual increasing recently, on the contrary, that of Samcheok, Imwon, and Chuksan was decreased. Pollution index involving multi-indictors relation to organics and inorganics was necessary for water quality assessment. Designated water quality criteria needed to be improved because the criteria of Jukbyun and Chuksan was applied more strictly compared to the other regions although without difference of environmental characteristics. Furthermore, the criteria notified lately needed to be related to management pollutants from land-based sources. The continuous diagnosis and monitoring on sediment quality within the study area were necessary for prevention of water pollution and eco-friendly disposal of dredged sediment. Especially, monitoring of Designated Ports was implemented partially, however monitoring ratio of National Fishing Har-bors was 7% to whole part. Therefore, systematic and integrated environmental monitoring for ports and harbors with charge of national management was reestablished by strengthening and securing a legal basis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.125-132
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• 2007

We estimated the distribution of predator-prey interaction strengths for 12 species of herbivores (including amphipods, isopods, gastropods, and sea urchins) and made a regression model that may be applicable to other species. Laboratory experiments were used to determine per capita grazing rate (PCGR; g seaweeds/individual/day). Relationship between the biomass of individual grazers and fourth-root transformed PCGR was fitted to power curve ($y=0.2310x^{0.3290}$, r=0.8864). This finding supported that the grazing efficiency was not even as individual grazers increase in size (biomass). Therefore, the biomass-normalized PCGR was estimated and revealed that smaller size herbivores were more effective grazers. Grazing impact considering density of each taxon was calculated. The sea hare Aplysia kurodai had greatest grazing impact on the seaweed bed and the sea urchin Strongylocentrotus nudus and S. intermedius were ranked in descending order of the impact. The amount of seaweed grazed by the amphipod Elasmopus sp. (>4,000 $ind./m^2$) and Jassa falcata (>2,000 $ind./m^2$) were 3.435 and $1.697mg/m^2/day$ respectively. The combined grazing amount of herbivores was $5,045mg/m^2/day$ in the seaweed bed. Although sea hare and sea urchin had strong impacts on seaweeds, the effects of dense, smaller species could not be seen as negligible. Surprisingly, the calculated grazing potential of sea urchins with a mean density of 3 $ind./m^2$ exceeded the mean production of seaweed cultured in domestic coastal waters in Korea (ca., 5 ton/ha). Small crustaceans were also expected to consume up to 16% of the seaweed production if their densities were rising under weak predation conditions. Considering that the population density of herbivores are strongly controlled by fish, human interference like overfishing may have strong negative effects on persistence of seaweeds communities.

• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.13-19
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• 2018

Following the 2016 Gyeongju earthquake, the Pohang Earthquake occurred in 2017, and the south-east region in Korea is under the threat of an earthquake. Especially, in the Pohang Earthquake, the liquefaction phenomenon occurred in the sedimentation area of the coast, and preparation of countermeasures is very important. The soil liquefaction can affect the underground facilities directly as well as various structures on the ground. Therefore, it is necessary to identify the liquefaction risk of facilities and the structures against the possible earthquakes and to prepare countermeasures to minimize them. In this study, we investigated the seismic liquefaction risk about the electric power utility tunnels in the southeast area where the earthquake occurred in Korea recently. In the analysis of seismic liquefaction risk, the earthquake with return period 1000 years and liquefaction potential index are used. The liquefaction risk analysis was conducted in two stages. In the first stage, the liquefaction risk was analyzed by calculating the liquefaction potential index using the ground survey data of the location of electric power utility tunnels in the southeast region. At that time, the seismic amplification in soil layer was considered by soil amplification factor according to the soil classification. In the second stage, the liquefaction risk analysis based on the site response analyses inputted 3 earthquake records were performed for the locations determined to be dangerous from the first step analysis, and the final liquefaction potential index was recalculated. In the analysis, the site investigation data were used from the National Geotechnical Information DB Center. Finally, it can be found that the proposed two stage assessments for liquefaction risk that the macro assessment of liquefaction risk for the underground facilities including the electric power utility tunnel in Korea is carried out at the first stage, and the second risk assessment is performed again with site response analysis for the dangerous regions of the first stage assessment is reasonable and effective.