• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.2
• /
• pp.45-58
• /
• 2015

The aim of this study is to find out major accumulation zones through field survey and moving route tracking trials on floating debris of Nakdong River. It also identified composition and accumulated amount of the floating debris by sample survey for accumulation zones. As a result, total 5 accumulation zones were selected from the midstream and downstream of the Nakdong River. There was a large amount of floating debris, including vegetation debris, in the accumulation zones. And two accumulation zones located in the downstream region, it is much more likely to flow into the ocean along river. From the sample survey on the major accumulation zones, more than $40{\ell}$ of floating debris were collected including vegetation and artificial debris. As a result of composition analysis for artificial debris, plastic(49%) and styrofoam(36%) were the majority in number. The present study is expected to help to plan an efficient pre-collecting activity and to reduce floating debris flowing into the ocean from the Nakdong River.

• Geophysics and Geophysical Exploration
• /
• v.6 no.4
• /
• pp.207-214
• /
• 2003

To analyze soil properties with depth in rice field, we compared resistivity distributions obtained from soil analysis with one dimensional inversion of small loop electromagnetic (EM) data. Although it didn't show consistency exactly between the two resistivity distributions, low resistivity zones in soil analysis, appeared to agree with low resistivity zones in EM result. Therefore, small loop EM method can be applied to obtain rapidly the soil properties such as salt accumulation in a rice field. If research on soil property and EM responses of unsaturated zone would be conducted consistently, small loop EM method can be used effectively to detect salt accumulated zone in agricultural area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.1
• /
• pp.24-31
• /
• 2007

Global fates of polychlorinated biphenyl(PCB) were investigated with a fugacity based multimedia transport and fate model, Globe-POP(persistent organic pollutant). The accumulation of PCB was directly affected by the emission patterns of PCB into the atmosphere and surface areas of environmental compartments. Partition coefficients and reaction rates also influenced on the accumulation patterns of PCB. The emission patterns of PCB in 10 climate zones were consistent for the past 70 years, while the contribution of PCB in high-latitude zones to the globe has increased by cold condensation. Considering the amounts of emission and accumulation of PCB, the North temperature zone is regarded as an important source and sink of PCB. Meanwhile, in spite of no significant sources, POPs accumulate in Antarctic environments mainly due to extremely low temperature. Finally we suggested that a global water balance accounting for snow/ice should be incorporated into multimedia environmental models for high-latitude zones and polar regions with the seasonal snow pack and/or permanent ice caps. The modified model will be useful to evaluate the influence of climate change on the fate of POPs.

• Journal of Korea Water Resources Association
• /
• v.36 no.5
• /
• pp.851-861
• /
• 2003

Snow accumulation and snow melt was simulated and included in the computation of the watershed runoff for Soyanggang Dam and Chungju Dam. A modified Tank Model was used for the simulation, which has three serial tanks and a pulse response function. The model parameters were estimated through the global optimization method of Shuffled Complex Evolution-University of Arizona (SCE-UA). A watershed was divided into four zones of elevation. The temperature decrease of the zones was a rate of -0.6$^{\circ}C$/100m. Almost all precipitation from December to February become accumulated as snow, and then the snow melts and runs off from March to April. The average runoff with snow melt was greater than the average runoff without snow melt during the period from March to April. The improved amount from snow melt simulation was about one fifth of the observed one for Soyanggang Dam. The increased amount for Chungju Dam was about one fourth of the observed average runoff during the same period. Although the watershed runoff was simulated including snow melt, it was less than the observed one for both of the dams.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.25 no.3
• /
• pp.29-45
• /
• 2022

For biodiversity conservation, the importance of beta-diversity which is changes in the composition of species according to environmental changes has become emphasized. However, given the systematic investigation of species distribution and the accumulation of large amounts of data in the Republic of Korea(ROK), research on the spatialization of beta-diversity using them is insufficient. Accordingly, this research investigated the applicability of the Generalized Dissimilarity Modeling(GDM) to ROK, which can predict and map the similarity of compositional turnover (beta-diversity) based on environmental variables. A brief overview of the statistical description on using GDM was presented, and a model was fitted using the flora distribution data(410,621points) from the National Ecosystem Survey and various environmental spatial data including climate, soil, topography, and land cover. Procedures and appropriated spatial units required to improve the explanatory power of the model were presented. As a result, it was found that geographical distance, temperature annual range, summer temperature, winter precipitation, and soil factors affect the dissimilarity of the vegetation community composition. In addition, as a result of predicting the similarity of vegetation composition across the nation, and classifying them into 20 and 100 zones, the similarity was high mainly in the central inland area, and tends to decrease toward the mountainous areas, southern coastal regions, and island including Jeju island, which means the composition of the vegetation community is unique and beta diversity is high. In addition, it was identified that the number of common species between zones decreased as the geographic distance between zones increased. It classified the spatial distribution of plant community composition in a quantitative and objective way, but additional research and verification are needed for practical application. It is expected that research on community-level biodiversity modeling in the ROK will be conducted more actively based on this study.

• Economic and Environmental Geology
• /
• v.38 no.2 s.171
• /
• pp.197-206
• /
• 2005

North Korea is plentiful in the mineral resources as magnesite, gold, zinc, iron, rare metal, and coal resources compared to South Korea and has 6 industrial zones which are located nearby to the mineralized areas. The industrial zones are provided with a sound infrastructures and accumulation of advanced technology. As a huge mineral and energy consuming country, South Korea imports mineral and coal resources equivalent to almost 8 trillion won annually. Inter-Korean cooperation for development of mineral resources in North Korea will be improved by the practical use of the North Korea's plentiful mineral resources, infiastructures related to development and refinement, and basic geo-technology, which would be considered toward combining with South Korean capital and Russian geo-technologies.

• 한국해양학회지
• /
• v.30 no.4
• /
• pp.288-301
• /
• 1995

Rates of the sedimentation and particle mixing have been estimated by applying uranium-series disequilibrium techniques to three sediment cores collected from the korea Deep Ocean Study (KODOS) site between the clarion and Clipperton Fracture Zones (CCFZ) of the Equatorial Pacific. Sedimentation rates based on the profiles of excess /SUP 230/Th activity and /SUP 230/ Th/SUB xs//SUP 232/ Th activity ratios at the southeastern part of the study area were estimated to be in the order of a few millimeters per thousand year, while at the northwestern part a factor of ten lower. Excess activities of /SUP 230/Th and /SUP 230/Th ratios showed intervals of constant values in the upper part of the sediment cores, probably generated by biological particle mixing. A "two-box" advection-diffusion steady state mixing model was employed in order to estimate particle mixing rates in the upper and the lower layers, based on the distribution profiles of excess /SUP 210/Pb activities. Particle mixing coefficients were estimated to be in the order of 10$^1$ cm$^2$/y in the upper layer and 10/SUP -1/-10/SUP 0/ cm$^2$/y in the lower layer.

• Korean Journal of Environmental Biology
• /
• v.21 no.3
• /
• pp.257-261
• /
• 2003

Population of small mammals (Apodemus agrarius and Crocidura lasiura) was monitored to identify the bioaccumulation of heavy metals in Gumho river basin around Daegu city. The small mammals were captured during 28 of May~12 of June, 2002. The techniques of live-trapping and snap-trapping were applied to capture the animals. A total of 39 animals were captured among which 53.3% (16130) of population were reached to breeding. Heavy metals (Cu, Pb, Zn, Cd) were analyzed. According to the analysis of heavy metal elements, Zn was more accumulated in kidney (6.83 mg $kg^{-1}$) than in liver (3.66). However, the accumulation of Cu was higher in liver than in kidney. Even though this site was relatively away from major industrial zones, heavy metals were wide spread along the stream of Gumbo River. This is the first quantitative study of small mammal bioaccumulation of heavy metals in Korea so that further research should be followed in other industrial areas that heavy metals were widely dispersed.

• Advances in Traditional Medicine
• /
• v.2 no.2
• /
• pp.94-100
• /
• 2002

Liver cirrhosis is characterized by hyperaccumulation of fibrous tissue components and is commonly observed in latter or terminal states of chronic hepatic diseases. In this study, the antifibrotic effects of GLM001 on liver cirrhosis were examined in bile duct ligated rats and patients with hepatic diseases. GLM001 (250 mg/kg rat weight/ day) was administrated to cirrhotic rats for 4 weeks and to humans for 14 weeks. Bile duct ligated rats significantly increased liver collagen content and biochemical markers of hepatic injury. Liver histology showed collagen fiber deposition was increased and the normal architecture was lost with large zones of necrosis being observed frequently. GLM001 administrated rats showed significantly decreased liver collagen content, and accumulation of collagen fiber in histological analysis. Patients, who were treated with GLM001, showed decreases in biochemical markers of hepatic diseases. These results demonstrate the usefulness of GLM001 as an antifibrotic agent for liver cirrhosis.

• The Korean Journal of Ecology
• /
• v.24 no.5
• /
• pp.297-301
• /
• 2001

The objectives of this study were to evaluate the extent of heavy metals(As, Pb, Cd, Hg)accumulated in sediments of the Kwangyang Bay, and to investigate bioaccumulation of heavy metals(As, Pb, Cd, Hg) in shellfish(Ruditapes philippinarum) commonly found in the intertidal zone of the Kwangyang Bay. The data was also compared with that of Namhae and Kohung intertidal zones, which were regarded as control stations in this study. Substantial geographical variations in heavy metal concentrations in the sediment samples were found. However, heavy metal concentrations in the sediment collected from the intertidal zones of Yochon(stations I, J) and Myodo(stations G, H) close to Yochon Industrial Area exhibited relatively higher heavy metal concentrations, compared to those from other intertidal zones(stations A, B, C) adjacent to POSCO at Kwangyang Bay. In addition, stations A, B, C showed lower heavy metal concentrations in the sediments than controls(K, L). The annual mean concentrations of the heavy metals in the shellfish from the stations(G, H, I, J) were significantly higher than those from other stations(A, B, C, D, E, F). Nevertheless, heavy metal accumulation in sediments was not reflected in bioaccumulation of heavy metals in shellfish, probably indicating that interactions between the heavy metals in sediment and shellfish might be poor in the current study area, Kwangyang Bay.