• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.3
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• pp.189-201
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• 2013

To study characteristics of the water quality in the Hansan-Geoje bay, we analyzed the long term monitoring data collected at the two sites during the period of 1987~2010. The trophic state of the waters in Hansan-Geoje bay was the mesotrophic level by the classification of Wasmud et al.[2001]. The water nutrients increased steadily from a wet season (Aug.), it reached the maximum concentration peak in a dry season (Nov.), and then decreased steadily to the winter, it reached at the minimum value in May in the next year. The result of factor analysis divided the waters of Hansan-Geoje bay into the five factors (nutrient, season, inflow land water, pollution, internal production) and the factors represented the 76.82% on the status of the waters. According to time series analysis, temperature, DO and bottom DIP were increased, and pH and COD were decreased during the period of 1987~2010. In particular, the fluctuation trend of DIN has been turned from oversupply to shortage by the N/P ratio since before and after 1990's. The water quality of the Hansan-Geoje bay has been recovered except DIP since 1987, despite of its geographical characteristic which is a general semi-closesd bay and a massive aqua-culture ground. To preserve the waters in Hansan-Geoje bay, we need to know on the cause of the increase or accumulation of DIP, and we should continue to study on the interrelation between the aqua-culture and water environment.

• Journal of Conservation Science
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• v.18 s.18
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• pp.63-74
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• 2006

All rock materials of the three storied stone pagoda in Seoakri were composed of light gray alkali granite with medium grained and developed with small mialolitic cavities. This stone pagoda is preserving almost archetype except the head part because there was repair work already. But, foundation, basement and roof rocks are serious state by microbial invasion such as lichens. Because there are tree and grass that cause direct effect to stone pagoda surrounding. Therefore, conservation treatment executed the primary dry cleaning and secondary wet cleaning treatment. Stone surface is partly not removed well such as lichens which part removed using cleansing device that use high temperature steam. Some treated part concrete and epoxy resin remove and retreatment with mixing talc and alkali granite powder to epoxy resin. Did color matching at mixing process of epoxy resin and fillers to properties with set the feel of a material. Also, drainage ditched to minimize inflow of rainwater fall from slope that is on the east of stone pagoda, tree and grass in stone pagoda surrounding wished to do remove and control occurrence of lichens hereafter minimizing moisture conteats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.294-305
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• 1989

Basedon statistical data of pomfret (Pampus spp.) catches by the stow net during $1970\~1985$, the distribution and migration of pomfrets and fishing conditions were investigated in relation to oceanographic conditions, in the East China Sea and the Yellow Sea. The main fishing grounds of Pomfrets were formed around the Great Yangtze Sand Bank which locates between the Cheju Island and the mouth of the Yangtze River. Its area occupied only 11 percent of all fishing grounds, and about 70 percent of total catch was found there. The coefficient of variation(CV) in catch was below 0.01 in the whole fishing grounds and that of tile main fishing grounds (14 fishing areas) was $0.001\~0.003$. This area was indicated markedly by the inflow of Yellow Sea Warm Current from spring to autumn, and this mixing area which formed the oceanic front among the China Continental Shelf Water, the Yellow Sea Bottom Cold Water and the Tsushima Warm Current. The pomfrets migrates to south-north according to the expansion and contraction of the Tsushima Warm Current including the Yellow Sea Warm Current and the Yellow Sea Bottom Cold Water. Therefore, it migrates to north of the Yellow Sea in summer and to southern part of the East China Sea in winter. The most frequent range of the water type for high catch was $10\~12^{\circ}C$ in temperature and $32.4\~33.4\%_{circ}$ in salinity. The ranges was occupied more than 70 percent of total catch on fishing season. The frequency range of the water type was not different between the abundant fishing periods and the poor fishing periods in terms of the maximum catches.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.124-138
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• 2017

Physico-chemical measurement of non-refractory submicron particles($NR-PM_1$) was conducted in Baengnyeong Island, Korea using Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) from 2012 to 2014. Organics and ammoniated sulfate were dominant species in $NR-PM_1$. The organics was found to have similar fractions(approximate 40%) of $NR-PM_1$ during the summer and winter, while the sulfate fractions of $NR-PM_1$ were calculated to be approximately 47% and 31% for the summer and winter, respectively, suggesting the possibility that particles provide non-acidic surfaces for condensation of nitric acid in the winter. The nitrate fractions of approximate 4% and 20% of $NR-PM_1$ were observed in August (summer) and November (winter), respectively, resulting that the relatively low concentration of sulfate in $NR-PM_1$ provided a non-acidic surface for nitric acid condensation and formation of particulate ammoniated nitrate is favored thermodynamically in winter. The new particle formation (NPF) event and particle growth rate were analyzed for each month in 2014 using Scanning Mobility Particle Sizer(SMPS). The Percent of NPF events was the highest in winter, but NPF event was not observed during summer due to relatively high temperature and frequent rainfall. The average particle growth rate was 3.5 nm/h and the highest particle growth rate was 5.5 nm/h in May. We observed the long-range transport of the anthropogenic sulfate from the East Asia during the intensive monitoring period of November between Qingdao and Baengnyeong Island in 2013. The relatively high concentrations of m/z 60 measured in HR-ToF-AMS was observed in May and June at Baengnyeong Island, suggesting the possibility of the influence of biomass burning from the East Asia to the Korean Peninsula.

• Journal of Conservation Science
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• v.27 no.4
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• pp.381-393
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• 2011

This study focus on the surface deterioration diagnosis based on the material characteristics of Taean Dongmunri Maaesamjonbulipsang(rock-carved standing triad Buddha Statue) and the weathering environment analysis. Rock materials of the triad Buddha is coarse-grained biotite granite which is composed mainly of quartz, K-feldspar, plagioclase, biotite and muscovite. The triad Buddha was serious surface irregularity(13.5%), exfoliation(12.3%) and discoloration(46.6%), and the physical characteristics using ultrasonic velocity appeared fourth grade (0.59, highly weathered). Korean style wooden shelter of the triad Buddha(closed type) maintained high humidity environment (daily mean; 86.6%) than exterior environment, and appeared the possibility of deterioration by freezing-thawing because the temperature showed below zero temperatures in winter. The shelter was changed from closed-type to open-type to relieve the moisture problem recently. But the moisture problem is yet to be solved because surface water flowing along northern wayside is flowed into triad Buddha. Therefore, environmental control will need to stop inflow of water into triad Buddha.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.29-39
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• 2018

Long-term variation of zooplankton community and species composition was studied from 2003 to 2014 in a deep reservoir, Lake Soyang, in monsoon climate region, Korea. In addition, we examined the correlation with environmental factors. Annual precipitation of watershed showed a large variation in the $705{\sim}1,779mm\;yr^{-1}$ and more than 70% of it was being concentrated from June to September. The water quality of Lake Soyang was shown a clearly seasonal variations and particularly turbid water flowing into the lake during rainy season was the most important environmental factors. Zooplankton community in Lake Soyang showed a significant difference before and after 2006. Zooplankton biomass has shown a large increase and also showed a change in the zooplankton community structure since 2006. The of zooplankton showed positive correlation with temperature and BOD, Chl. a, TP concentration. These results are considered that nutrient and organic matter contained in the turbid water influences the increase in zooplankton biomass and species composition. However, water quality was limited to account for the increase in biomass of zooplankton. For example, increase of small zooplankton density (rotifer; Keratella cochlearis, Polyarthra vulgaris) in spring which is dominated by diatoms (large size; Melosira, Synedra etc.) is considered as a bottom-up effect by the microbial loop. And increased density of crustaceans in autumn was considered a top-down effects by the relationship between predator and prey of microzooplankton and mesozooplankton. In other words the inflow of allochthonous organic matter during rainy season also affected to zooplankton food web in Lake Soyang. In conclusion, biomass, diversity and long-term variations of zooplankton in Lake Soyang were determined by physico-chemical factors but also it is considered that biological interactions is important.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.139-149
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• 2012

Four in situ incubation experiments were conducted in May, August and November 2009, as well as February 2010 to determine the seasonal primary productivity and the community structure of phytoplankton at the Seomjin estuary. The primary production of phytoplankton ranged from 9 to 3560 mgC $m^{-2}\;d^{-1}$. Primary productivity was the highest in the summer season (August), which was influenced by improved optical and temperature conditions of the water, as well as the supply of nutrients derived from its surrounding watershed. Particularly, the upper station (SJ-1, SJ-2) of Seom-jin estuary showed a higher productivity, as a result of inflow of input nutrients originated from the terrestrial source. The fucoxanthin, as an index pigment of diatoms showed the highest concentration (0.74~9.51 ${\mu}g\;L^{-1}$) at all stations, occupying 30~80% to total Chl a concentrations. The phytoplankton species composition determination, using a microscope showed similar results to the pigment analysis, which indicated diatom Skeletonema costatum, as the dominant species. The primary productivity in Seom-jin estuary indicates temporally and spatially large variation, according to different environmental conditions. Also, Skeletonema costatum has euryhaline features with relatively higher contribution.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.202-208
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• 2009

In order to understand the circulation of nutrient between muddy tidal flat and the surrounding coastal area, tidal time-scale variations in nutrient concentrations were seasonally investigated at the entrance of Hampyeong Bay. The results show that the temperature was higher in ebb tide and lower in flood tide during the summer, but it was lower in ebb tide and higher in flood tide during the autumn/winter. The salinity was higher in flood tide and lower in ebb tide during the summer/winter because of the inflow of external sea water resulting from the increase in the tide level. By contrast, the salinity was lower in flood tide and higher in ebb tide during the autumn. Salinity difference was lower than 0.3 psu between flood tide and ebb tide during survey period. Meanwhile, all nutrient concentrations observed in Hampyeong Bay was lower in flood tide and higher in ebb tide during the summer, and by contrast, it was higher in flood tide and lower in ebb tide during the winter. Characteristically, no clear variation of concentrations was found depending on the tide level during the autumn. This tidal variations imply that the muddy tidal flat of Hampyeong Bay supplies nutrients to the seawater in summer and removes nutrient from the seawater in winter. During tidal cycle, seasonal variation of nutrient concentration in seawater is considered as the result of complex interactions between the mud flat and external sea water.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.232-241
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• 2010

Epilithic diatom communities and water quality were monitored to evaluate the ecological impact of the inflow of Wonju-stream passing through the urban area in the Seom River Watershed. We selected the 14 sampling stations (5 main stream sites and 9 tributary sites), and collected diatom and water samples between October 2007 and September 2008, on the seasonal basis. The results indicate that most water quality parameters showed the site-specific patterns over the study, except for water temperature and dissolved oxygen. The levels of water quality parameters were highest at the site of Wonju stream, whereas the lowest in the upstream sites, and intermediate or gradually decreased in the downstream sites of the Seom river. One species, Achnanthes convergens, showed the highest biomass and frequency over the sites, while three saprophilous species-Navicula goeppertiana, Navicula subminuscula, Nitzschia palea were appeared only in Wonju Stream and other polluted sites. According to trophic diatom index (TDI) values, which were highly correlated with nutrients and EC, the study sites were classified into three classes: upstream and tributary (Class A and B), Wonju Stream (Class D), and mixed zone and downstream (Class C). A cluster analysis supported the result of TDI classification. Therefore, Wonju-stream located in populated urban area exerted the adverse ecological effects on the epilithic diatom community and water quality of the lower Seom River System, although its severity gradually decreased downstream.

• Korean Journal of Medicinal Crop Science
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• v.19 no.3
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• pp.157-161
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• 2011

Growth characteristics, root yield and ginsenoside contents of 3-year-old ginseng in greenhouse shaded by $30^{\circ}$ sloped-curtain made of aluminum were compared to traditional shade facility in order to develop cultural practice for organic ginseng. Light transmittance ratio in greenhouse with $30^{\circ}$ sloped-curtain shade was distinctly lower than that of traditional shade from sunrise to 9 a.m., while its ratio in greenhouse was higher than traditional shade since 9 a.m. due to the reflection of light. Air temperature of greenhouse was $1.3^{\circ}C$ higher than that of traditional shade on the first ten days of August due to more reflected light. Root yield of greenhouse was 44% higher than that of traditional cultivation because of the inflow of reflected light and the decrease of disease of Alternaria and Anthracnose by blocking rainfall. Dry matter partitioning ratio of rhizome and lateral root were increased in ginseng cultivated at greenhouse due to longer survival time in leaf than traditional cultivation. Total ginsenoside contents cultivated at greenhouse was decreased in the part of taproot, while it was increased in the part of lateral and fine root compare to traditional cultivation. Individual ginsenoside contents between greenhouse and traditional cultivation showed significant difference more frequent in fine root than taproot and lateral root. Total ginsenoside contents including $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, and $Rg_2$ in whole root of 3-year-old ginseng did not showed significant difference by greenhouse and traditional cultivation.