• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.1-10
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• 2016

In this paper, an analysis of the inflowing pollution load of the rivers in Hampyeong bay showed the average organic matter pollution loads of BOD, COD, and TOC to be 79.7 kg-BOD/day, 144.06 kg-COD/day, and 93.0 kg-TOC/day, respectively. The inflowing organic matter pollution load was the heaviest in Sonbul dike, followed by Jupo bridge and Yangman complex. With regard to season, the load characteristics were outstanding in July, the rainy period in the summer. The average inflowing pollution loads of nutrients were 20.9 kg-DIN/day, 17.1 kg-DIP/day, 148 kg-TN/day, and 37.4 kg-TP/day A comparison of the inflowing nutrients loads for each river showed the load to be the heaviest in Yangman complex, followed by Baegok bridge and Jupo bridge. In the experiment on the material budgets of Hampyeong bridge conducted using a box model, the detention time of fresh water was found to be 52.4 days, with the bay displaying the characteristics of a so dissolved inorganic nitrogen (DIN) in the nutrients material budgets, ${\Delta}DIN$ values were found to be negative, indicating the tendency of consumption and open sea leak by photosynthesis to be higher than the nitrogen that flowed in. As for dissolved inorganic phosphorus (DIP), ${\Delta}DIP$ showed positive values, indicating a tendency for accumulation as the supply through organic matter decomposition, elution load of sediments, and inflowing load of the river turned out to be higher than the consumption by phytoplankton and outflow to open sea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.45-54
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• 2008

"Summer Deadweight Tonnage(SDWT)" is used as the criteria of the berthing capacity when establishing port entry limits under current guideline. The important factors affecting to the maximum ship size of possible berthing are mass, length and breath of the ship rather than deadweight. Therefore this guideline should be modified to ensure safety and efficient operation of berth. This study aimed to propose a rational guideline to adjust the berthing capacity. In order to decide proper berthing capacity, three berths of Port of Ulsan were selected and systematic evaluations for the safety of passage transit, berthing maneuvers, ship motions at berth and stabilities of structures were conducted. Small changes of ship size had little effect on those characteristics and little significant differences were found according to the increase of ship size at the same displacement. The evaluation results of the increasement of 50% of berthing capacity at 20,000 DWT, 25% at 40,000 DWT and 13% at 150,000 DWT were within the design criteria in which the berths were built. Therefore, if the channel width, diameter of turning circle, berth length and mooring arrangements are satisfied with the criteria, the current berth limitations should be adjusted by the displacement. as substitute for the deadweight.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.379-387
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• 2012

In order to see the oceanographic conditions, the observations of aquaculture farm of ascidian in Youngdeuk, the east coast of Korea were conducted through 6 times-23 February, 6 April, 8 June, 19 August, 6 October and 20 December-in 2010. Surveys were conducted in 20 stations bimonthly using SBE 19 CTD instrument. The mixed layer depth (MLD) was deep in winter and shallow in summer. The cold water below $5^{\circ}C$ in temperature was occupied below thermocline through all season. The temperature was high in the southeastern area. The salinity was increased from the coast to the open sea. The halocline was distinct at 20 m depth in August and at 40 m depth in October. The lowest value of salinity was appeared at the depth of 10 m in October. In addition the value of precipitation minus evaporation denoted negative in October. These low saline water seemed to inflow to the coast from the open sea. Therefore the low saline water moved to the east coast of Korea. The EKWC may play an important role to convey the low saline water. It may affect the aquaculture farm along the coast as the mass mortality of ascidian. It needs to clarify the role and pathway of EKWC to transfer the low saline water along the east coast of Korea.

• Korean Journal of Environment and Ecology
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• v.1 no.1
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• pp.24-34
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• 1987

This study was conducted to investigate avifauna and user's effect on the avifauna in Bukhan Mountain district of Bukhan Mountain National Park. Avifauna were investigated bimonthly from April to October 1987 over four districts which were main trail and sub-trail in each valley and ridge-midslope region by line transect methods. The observed birds in Bukhan Mountain districts was 34 species and 753 individuals and these consist of 19 species for residents. 11 species for summer visitor. 2 species for passage migrant and 2 species for winter visitor. The dominant species were Parus major (22.7%), Paradoxornis webbina(10%), Parus palustris (10.8%), Pica pica (10.0%) in order. No. of species and species diversities was higher in valley region than in ridge-midslope region. No. of species, individuals and species diversities were lower in main trail of high user's density than in sub-trail. Especially avifauna in main trail was severely decreased in August in valley region in which users were concentrated. But there was no change in similarity indices according to user's intensities. Therefore avifauna protection policy such as restoration and rehabilitation of edge species along trail, user's control in valley region during breeding periods, etc., shall be made for Bukhan Mountain National Park.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.79-90
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• 1991

This study was conducted to investigate seasonal avifauna and to suggest a proper way how to manage and protect wild birds in Chirisan National Park. The survey was carried over 3 main trail districts by line transect method to figure out influence factor of inhabitation of wild birds from February to November in 1991. The study results are as follows : The observed birds were belong to 6 orders 24 families 49 species and 981 individuals and Falco tinnunculus(Natural monument No. 323). These birds also classified into 24 species for residents, 12 species for summer visitor. 9 species for winter visitor, 4 species for passage migrant, respectively. The observed average frequeney of birds was 2.09e.a./ha, and main dominant species were Parus varius, Parus major, Emberiza elegans, Garrolus glandarius, Sitta europaea, Hypsipetes amaurotis, Parus palustris in order. Cheoneun-sa trail route showed relatively decreasing trend of wild birds during spring and fall season because of the highest trail use of visitors. Maximum frequency of species and individuals appeared at Hwaum-sa route in spring and at Piagol route in fall. respectively. Those regions well explained the advantageous inhabitation area of birds in both regions. The diversity index of birds in winter showed little difference of similarity index due to balanced use of trails. Seasonal low similarity index in those 3 main trail district indicate a dissimilarity of environmental factors. Trail use restriction as a provision of proper management and protection of wild birds have to be made at Hwaum-sa route where propagation of birds actively occurred in spring and at Piagol route where birds wintering were observed will contribute to enhance species diversity in the future.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.655-665
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• 2013

This study was carried out to investigate the community structure and biomass of benthic marine algae at the intertidal and subtidal zones of Eocheongdo on the western coast of Korea seasonally from July 2008 to April 2009. Total 101 species including 12 of green algae, 23 of brown algae and 66 of red algae were collected and identified. Among these species, 19 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Corallina pilulifera, Gelidium elegans, Sargassum thunbergii, Sargassum fusiforme, Saccharina japonica, Sargassum honeri and Sargassum filicinum. Annual seaweed biomass in dry weight was $237.5gm^{-2}$ and maximum biomass was recorded seasonally in winter ($272.1gm^{-2}$), while minimum was recorded in summer ($204.5gm^{-2}$). The number of species and biomass of the subtidal zone were greater than those of the intertidal zone. The number of species and biomass in Eocheongdo seem to be higher than those of other islands in the western coast of Korea, due to the environmental conditions characterized by the increased transparency, and the well established rocky shore.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.310-318
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• 2001

In the large regulated Nakdong River, the Predation effect of juvenile fish on the zooplankton community was evaluated by gut and stomach analyses of fish in 1999. Juvenile fish of five species showed high density from May to early June when river discharge was low and water body became stagnant. During this period, large rotifers, Asplanchna spp. and Brachionus spp. declined and the decrease of cladoceran (Moina micrura and Bosminopsis deitersi) density was also obeserved. At this time, small rotifers including Polyarthra spp. reached maximum density. Gut analysis of fish demonstrated that small-sized juvenile fish (< 15 mm in total length)preferred large rotifers as well as cladocerans, while large sized fish (> 15 mm)selected only cladocerans. On the other hand, juvenile Micropterus salmoides of which size was larger than other juvenile fish consumed not only zooplankton but also other small juvenile fish. Based on these results, the decline of large rotifers and cladocerans during early summer in the river seems to be result of predation by juvenile fish. However, the period when juvenile fish maintained their high density was as short as one month and the decreased density of cladocera rapidly recovered as soon as juvenile fish became scarce. Such a short period of juvenile fish devel-opment in the river can be attributed to the consumption of juvenile fish by the young-of-the-year cohorts as well as adults of M. salmoides. The high trophic state of the river might permit the rapid recovery of the cladoceran community. The predation impact of juvenile fish in the Nakdong River seems to be affected by the existence of piscivore as well as high trophic status.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.4
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• pp.487-498
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• 2006

Total 438 precipitation samples were collected in Jeju City between 1997 and 2005, and their major ionic components were analyzed. The comparison tests using ion balance, electric conductivity and acid fraction were performed. It was found their correlation coefficients were in the range of 0.977$\sim$0.994, indicating the good quality of collected dam. The volume-weighted mean pH and electric conductivity were 4.8 and 23.0 $\mu$S/cm, respectively. with the ionic strength of 0.23$\pm$0.20 mM. The marine ($Na^+$, $Mg^{2+}$, and $CI^-$), anthropogenic (nss$SO_4{2-}$, $NO_3^-$, and $NH_4^+$) and soil (nss-$Ca^{2+}$) species have contributed to the ionic components of precipitation samples with 43$\sim$74%, 16$\sim$37% and $\sim$5%, respectively. The seasonal variations of $NO_3^-$ and nss-$SO_4^{2-}$ showed a distinct seasonality with higher concentrations in winter than summer, indicating an increase of fossil fuel consumption and a possibility of long-range transport of those pollutants from continental area along the dominant winter westerly. The levels of nss-$Ca^{2+}$ also were appeared the highest in winter and increased comparatively in spring season. possibly due to the soil influences including the Asian Dust. The acidification contribution of nss-$SO_4^{2-}$ and $NO_3^-$ showed 88$\sim$96%, and the free acidity was in the range of 6.0$\sim$40.1%. Interestingly, the backward trajectories for the case of upper 10% nss-$SO_4^{2-}$ and $NO_3^-$ levels have passed through the China continent before their arrival to Jeju. The precipitation of pH below 4.5 has been occurred frequently when the trajectory's path lied over the China continents. On the other hand, the air masses from the North Pacific area were characterized by lower 10% of nss-$SO_4^{2-}$- and $NO_3^-$ concentration, which demonstrated that air mass from the North Pacific was the cleanest among air masses moved to Jeju.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.4
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• pp.459-467
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• 2006

This study was carried out to characteristics and distributions of acid deposition in Korea. Precipitation was collected by acid deposition monitoring networks and analyzed for pH, conductivity, and following major ionic components $SO_4^{2-}$, $CI^-$, $NO_3^-$, $NH_4^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$. During the investigation period, Volume weighted annual mean pH of precipitation in Korea is 4.8, showing slightly acidic level. The amount of rainfall in the range of pH 5.1$\sim$5.5 charged approximately 28% of annual precipitation,23.4% in pH 4.6$\sim$5.0, and contributed 16.2% under pH 4.5. Among seasons, alkaline precipitation has occurred more often in spring, meanwhile acidic precipitation in which pH is under 4.5 has frequently occurred in autumn. Volume weighted annual mean concentrations of $SO_4^{2-}$, $NO_3^-$, $CI^-$ are 2.558 mg/L, 1.590 mg/L, 1.286 mg/L respectively, and provided that $SO_4^{2-}$, is the major contributor, followed by $NO_3^-$, $CI^-$. In case of cation, annual mean concentration for $NH_4^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$, $H^+$ are 0.693 mg/L, 0.528 mg/L, 0.439 mg/L, 0.455 mg/L, 0.089 mg/L,0.015 mg/L, and $NH_4$ were decided as the main contributor, followed by $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$, $H^+$. Annual wet deposition rate for sulfate, nitrate and ammonia are $3.316gm^{-2}yr^{-1}$, $2.057gm^{-2}yr{-1}$, $0.894gm^{-2}yr{-1}$, respectively, and it was founded that the deposition flux in summer contributes about 38.42% to 67.62% to total deposition.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.5
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• pp.371-381
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• 1997

Precipitation sampls were collected in Chonju-city during October 1994 to September 1995 and were analysed for major ions (N $a^{+}$, $K^{+}$, $Ca^{2+}$, $Mg^{2+}$, C $l^{[-10]}$ , NO/$_3$, S $O_4$$^{2-}$) and trace metals (Al, Cd, Ni, Pb, Sr, Zn) in addition to pH, in order to understand the chemical characteristics of acid rain and to estimate the origin of the determined ions. Most rain showed a neutral or alkaline character, and only 35% had a pH lower than 5.6. S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ are identified as the primary contributors to precipitation acidity in this region. Neutralization of precipitation acidity occurs as a result of the dissolution of alkaline compounds containing $Ca^{2+}$, $Mg^{2+}$ and $K^{+}$. S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ precipitation concentrations exhibit a seasonal pattern in which higher concentrations are observed during spring months and lower concentrations during summer months. However, the seasonal behavior of $H^{+}$ concentrations differs from this pattern, in that the highest concentrations occur during autumn months, owing to the different influence of neutralization processes. In all rain, S $O_4$$^{2-}$ concentration exceeded NO/$_3$$^{[-10]}$ concentration. The contribution of maritime sources to the total S $O_4$$^{2-}$ concentration was very low or negligible. For rain strongly affacted by yellow sand, $Ca^{2+}$, $Mg^{2+}$ and $K^{+}$ ions show a sharp increase in concentration, reflecting the increased amount of dust and soil suspended in atmosphere. At the same time, S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ concentrations are at their highest levels while $H^{+}$ values are not comparably elevated, presumably beacause much of the acidity has been neutralized by alkaline substances. The seasonal variance of trace metal concentrations in rainwater is similar to that of major cations. The annual wet flux of acidic pollutants and trace metals wat calculated to be as follows: N $O_3$$^{[-10]}$ ; 2.32 g/$m^2$, S $O_4$$^{2-}$, 5.34 g/$m^2$, Al; 6.30 mg/$m^2$, Cd; 0.62 mg/$m^2$, Ni; 4.08 mg/$m^2$, Pb: 9.76 mg/$m^2$, Sr; 5.94 mg/$m^2$, Zn; 111 mg/$m^2$./$m^2$.