• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.2 s.29
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• pp.111-118
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• 2007

Simple box budgets models are useful tools to understand the phenomena of natural system and to provide an insight into the complex processes including physical, chemical and biological processes occurring in natural system. Budgets of fresh water, salt and nutrients were estimated in order to clarify the characteristics of seasonal material cycle in the Masan Bay. Outflow volume of freshwater into system was approximately $307.4\times10^3\sim1,210\times10^3\;m^3/day$. Inflow masses of DIP and DIN were approximately $410.8\sim795.7\;kg/day$ and $4081.4\sim6525.3\;kg/day$, respectively. DIN is expected to accumulate in the system. The removal of nutrients from bottom sediments will contribute to the reduction of 21.0% of COD concentration in the system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.3
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• pp.173-181
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• 2007

A three-dimensional ecological model (EMT-3D) was applied to Tokyo Bay for the simulation of PFOA. EMT-3D was calibrated with seawater analysis data obtained from the study area in 2004. The simulated results of dissolved PFOA were in good agreement with the observed values, with a correlation coefficient(R) of 0.7115${\sim}$0.8759 and a coefficient of determination $(R^2)$ of 0.5062${\sim}$0.7672. The results of sensitivity analysis showed that partition rate, adsorption rate and settling rate were important factors for PFOA in particulate organic matter. In the case of PFOA in phytoplankton, bioconcentration factor, uptake rate and partition rate were important factors. Therefore, the parameters must be carefully considered in the modeling. In the case of 50% and 80% total loads reduction, concentration of dissolved PFOA was shown to be lower than 20ng/L and 10ng/L, respectively. In the case of reduction of loads from rivers in each prefecture, Tokyo prefecture was found to have the most influence on the change of dissolved PFOA in surface water while Chiba prefecture was found to have the most influnce on the change of dissolved PFOA in bottom water.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.448-454
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• 2010

This study investigated the effect of PCE and TCE as electron acceptors on the bacterial composition of dechlorinating communities. The enrichment cultures reductively dechlorinating PCE and TCE were developed from three environment samples using acetate as electron donor. The cultures were prepared by sequential enrichment, which was seeded with sediment and dredged soil. Denatured gradient gel electrophresis (DGGE) of 16S rRNA gene fragment was used to compare the microbial communities of these three enrichment cultures. After incubation for 4 weeks, the removal efficiencies of PCE and TCE were highest from Yeocheon site (87.37% and 84.46%, respectively). PCE and TCE as electron acceptors affected the bacterial diversity and community profiles in the enrichment cultures. DGGE analysis showed that the dominant bacteria in PCE and TCE enrichment were belonged to Clostridium sp., Desulfotomaculum sp., and uncultured bacteria.

• Journal of the Korean Geographical Society
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• v.51 no.5
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• pp.651-665
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• 2016

This paper tried to delimitate the location and scope of Nokdundo located in the Dumangang estuary. In 18th century, Nokdundo was an alluvial island formed by several tributaries divided from the mainstream of Dumangang. In the mid-19th century, Nokdundo was connected to the Russian territory because some tributaries were blocked by sediment flows. In many maps published in the Joseon Dynasty, the location and size of Nokdundo had not been depicted consistently with each other nor been described correctly. Because of the recurrent extinction-generating phenomena of waterways of the Dumangang due to sedimentation process, the location and scope of Nokdundo can be delimitated differently according to the era. According to the distance information of the records published in the 19th and 20th century, the scope of Nokdundo can be extended widely to the Maritime Province of Siberia. So, the author have set the Sodumangang(Karasik River) as the northern boundary of Nokdundo. The Karasik River is called Sodumangang by the Koreans living in the Maritime Province. As a tributary of the Dumangang, Sodumangang flows into the Posyet Bay. Nokdundo was an island separated from the Korean peninsula and the Maritime Province by the Dumangang and the Sodumangang respectively. Tributaries of the Dumangang have formed many alluvial islands at the mouth of Dumangang where the Dumangang meets with the East Sea. So, the possibility that Nokdundo was consisted of several islands can not be excluded.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.23-35
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• 2012

The optimum location of the prehistoric sites of Ulsan Metropolitan City are investigated by both quantile and natural breaks methods through GIS, and the settlement pattern is studied based on the possibility of presence of the prehistoric sites which are also analyzed with these methods. Such factors including elevation, slope, distance from the nearest water, aspect, geological features, soil drainage classes, subsoil and land use recommended are employed in the analysis. The optimum geographical environment is the place where it includes the water-base in the area that is the southern aspect of the gentle slope land of lowland. The geology is the Quaternary alluvium. The drainage class is fine and the deep soil saturn is the fine loamy soil and the recommendation of land use is the area that is the field. As a result of the forecast of distribution, the prehistoric sites showed the higher possibility of presence in the downstream region where the Taehwa river and Dongcheon river join because the region come close to the watercourse and the drinking water use is easy. And the aspect and elevation is the low area. The alluvium accumulated from the upper stream of the Taehwa river and Dongheon river was made roomily, the area where is suitable for the farming life. Therefore, this region is judged that the possibility of presence of the prehistoric sites is high.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.51-59
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• 2010

The sediments and soils around a mine are likely to be exposed to contamination of arsenic (As) through mining operations. In this study, the factors associated with As movement in soils around a closed zinc (Zn) mine were evaluated by the relationship of As distributions to physico-chemical properties of soils. A sequential extraction scheme, based on a soil P fractionation, was used to assess the As distributionsin solid phases. A significant difference in As distributions was found between paddy and upland soils. While As contents of paddy soils increased with soil depth, those of upland soils decreased with soil depth. In upland soils, As showed additional significant relationships to oxides of Si, Al and Fe. Although a major fraction of As in soils was found to be in the NaOH extractable fraction, As exhibited highly significant relationship to the Zn species that apparently originated from the mine. Therefore, As mobility around Zn mine seems to be governed by mass flow of the particulates containing As-associated Zn in paddy soils, whereas retention reactions such as adsorption, complexation, and precipitation seem to predominate in upland soils.

• Journal of the Korean Geographical Society
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• v.42 no.6
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• pp.879-897
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• 2007

The Royal District in Gyeungju-city was placed in lower surface of alluvial fan that was formed during the Last Glacial Age. During the Holocene, Bukcheon-river was reached in the dynamic equilibrium status and the form of river channel was similar or same to the present. The cases of dying people and carrying houses away by flood for ancient history in Gyeongju were six times, in 131, 160, 350, 496, 657 and 703. Like this big flood was happened at interval of $150{\sim}200$years. A period of big flood appearance in Bukcheon-river was extremely long. Therefore the people who had lived in Gyeongju for ancient history perceived that most part of riverbed of Bukcheon-river was a safety place from flood damages. Not only private houses. In east part of Bunhwangsa temple, that is, west side of Bukcheon-river where the river energy is maximum, a pillow block was built to prevent a lateral erosion but any artificial riverbank was not. In spite of high flood possibility in Bukcheon-river, there was no facility to prevent floods in this section. Also, deposits of flood are not identified. This point is very suggestive that Bukcheon-river did not flood for ancient history.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.1
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• pp.109-119
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• 2018

The purpose of this study is to analyze the geographical location information data and the damage trends according to the type of landform for the study of various cultural properties in 44 traditional places with national designated cultural properties damaged by the racing earthquake on September 12, 2016. The landform type was the most enclosed type, and the location type was more frequent in the surrounding area, such as urban and rural areas. The waterside type was located along rivers, rivers, valleys, lakes, and oceans except for the top of the mountain, but this area was found to be vulnerable to earthquakes, It is understood that it should be referred from cultural property management the side. 26 of the total 44 were temples. The elevation and slope increased with increasing of the flat type, the background type, the enclosed type, the mountain type, and the top type. Most often located on 1-20 % slopes, with the slope facing south more often than not. Within the 10 km range from the epicenter, 23% were concentrated, within the range of nearly 65 km, the background type was closest, and was concentrated in the northeast and southwest from the epicenter. In this study, it is meaningful to analyze earthquake damage in various aspects from the viewpoint of traditional space which is a landscaping cultural property and it will be used for planning, designing and managing traditional spaces.

• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.77-85
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• 2015

Siniperca scherzeri is major target species for restocking and restoration project as it is one of the economic species in South Korea. In this study, to investigate their ecological characteristics movement pattern and habitat characteristic of S. scherzeri were analyzed using radio telemetry. Three specimens released during spawning season, moved more than 10 km toward upstream from the release site. Whereas the remains released after spawning season, settled within 400 m of their release site except two specimens (Ss 11, 3.2 km; Ss, 15, 1.4 km). One of possible reason of upstream movement during spawning season is reproduction. The conditions of their settlement area is similar with reference conditions of their spawning ground. S. scherzeri were mainly detected near the edge of the water, and it may related with the facts that rocks are mainly located at the edge of the water and S. scherzeri prefers rocks for their shelter. AMD (Accumulated movement distance) positively related with body weight and condition factor K, but no significant relationship was identified with gender and total length. Daily movement boundary of S. scherzeri was $214.94m^2{\sim}3,257.19m^2$, and their movement was restricted near the edge of the water. The results of this study could be useful to restocking and restoration.

• Journal of the Korean Geotechnical Society
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• v.33 no.5
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• pp.5-13
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• 2017

The sand layer deposited in clay is called a sand seam, which is formed by inflow of sands due to river flooding or slope failure in the middle of sinking and sediment of clay. When the sand seam exists in clay layer, the drainage direction changes from one way to both ways, and the time of consolidation may be reduced. However, it is not clearly proved due to lack of studies of sand seam and currently is not reflected in the design of soft soil improvement. As a fundamental study about sand seam, the oedometer tests and constant rate of strain tests with Rowe cell were conducted on clay specimens with sand seam. For tests, a frozen method was specially designed for making the sand seam. It was concluded that the test results showed the sand seam affects the coefficient of consolidation of clay. If the thickness of sand seam exceeds 0.05 times of specimen height, the sand seam works as drainage layer of pore water horizontally as well as vertically, and consequently the consolidation is accelerated.