• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.153-171
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• 2018

This study focuses on the investigation of geologic distribution and stratigraphy in the eastern part of Yeongdeok-gun, based on Lidar imaging, detailed field survey, microscopic observations, SHRIMP and LA-MC-ICPMS U-Pb age dating, and a new geological map has been created. The stratigraphy of the study area is composed of the Paleoproterozoic metamorphic rocks consisting of banded gneisses of sedimentary origin and schists ($1841.5{\pm}9.6Ma$) of volcanic origin, Triassic Yeongdeok plutonic rocks ($249.1{\pm}2.3Ma$) and Pinkish granites ($242.4{\pm}2.4Ma$), Jurassic Changpo plutonic rocks ($193.2{\pm}1.9Ma{\sim}188.8{\pm}2.0Ma$) and Fine-grained granites ($192.9{\pm}1.7Ma$), Formations [Gyeongjeongdong Fm, Ullyeonsan Fm. (~108 Ma), Donghwachi Fm.] of the Early Cretaceous Gyeongsang Supergroup and acidic volcanic rocks and dykes erupted and intruded in the Late Cretaceous, Miocene intrusive rhyolitic tuffs ($23.1{\pm}0.2Ma{\sim}22.97{\pm}0.13Ma$) and sedimentary rocks of the Yeonghae basin, and the Quaternary sediments. The Triassic Pinkish granites, Jurassic Changpo plutonic rocks and Fine-grained granites are newly defined plutonic rocks in this study. Miocene intrusive rhyolitic tuffs bounded by the Yangsan Fault, which was first discovered in the north of Pohang city, are believed to play an important role in the understanding of the Miocene volcanic activity and the crustal deformation history on the Korean Peninsula. It is confirmed that The NNE-SSW-striking Yangsan Fault penetrating the central part of the study area and branch faults are predominant in the dextral movement and cutting all strata except the Quaternary sediments.

• 한국해양학회지
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• v.30 no.6
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• pp.550-564
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• 1995

The temporal and spatial characteristics of wind fields over the neighbouring seas of the Korean peninsula are investigated using 10-years daily wind data during 1978${\sim}$1987 which have been spatially smoothed and low-pass filtered. Long term annual and monthly means are examined for synoptic patterns and spectral analyses are made for temporal variability and spatial coherence. Spatial patterns of the annual mean wind stress and curl have a strong resemblance with those of monthly means during the winter season. Two outstanding periodicities are observed at 1 and 2 cycles per year. The synoptic winds over the study area are highly coherent at both the annual and semi-annual periodicities. However, each basin has its own characteristic spatial pattern. For instance, the prevailing wind during the winter season is northerIy over the northern East Sea (ES), Yellow Sea (YS), and northern East China Sea (ECS), while it is northwesterly over the southern ES and northesterly over the northern ES and southern ECS. At the same time, the wind stress curl is positive over the northern ES and southern ECS, while it is negative over the southern ES, YS and northern ECS. On the other hand, the wind field during the summer season, with its strength being much reduced, is completely different from that during the winter season, and frequent passage of tropical storms provokes large temporal variability over ECS. One remarkable point is that the annual cycle, dominated by the Siberian High, tends to propagate from northeast to southwest, i.e., from northern 25 toward southern ES, YS and ECS, while the semi-annual cycle propagates in the opposite direction, from southwest to northeast. The semi-annual periodicity may reflect development of extratropical cyclones in spring and fall which frequently cross the Korean peninsula. In higher frequencies, there are no dominant periodicities, but local winds over YS and ES are highly correlated for frequencies larger than 0.1 cycles per day and phase difference increases linearly with frequency. This linear increase of phase corresponds to phase speed of 550 and 730 km/d at 0.1 and 0.3 cpd, respectively, The phase speed is apparently coincident with moving speed of extratropical cyclones across the Korean peninsula in the west-east direction.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.4
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• pp.83-97
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• 2011

In this study, space allocation with an assessment system for improving the function of the ecological use and function of each space was undertaken to suggest appropriate goals and directions. Ogeum Park, used as the study site, is a stronghold green zone located in the fan-shaped area of the Songpa-gu green zone on a 22ha area site. The assessment system for this study consisted of a total of 3 steps: Step 1 includes the division of the spatial block, Step 2 assesses the proper functioning of each spatial block, while Step 3 includes space allocation and presents improvements for function by space. This study performed a basin analysis with the consideration that Ogeum Park is a forest area and divided the site into a total of 8 areas according to how the sections of land are used. The function of wildlife habitat included an analysis of plant ecology(vegetation type, vegetation layer, potential vegetation), animal ecology(wild birds), and waterways. The function of leisure and use included an analysis of gradients, noise, paths, status of use, and status of facilities. The evaluation of the function of habitat sorted items into native vegetation, vegetation diversification, vegetation potential, animal diversification and potential of animal habitats. The results of grading the evaluation scores by space in the function of habitat showed that the Areas IV and VII, which were 90% of the maximum point, were Grade A, Areas II and V were Grade B at 70% and Area I and VI were Grade C at 50%. Areas III and VIII, which were not found to be beyond the standard of 50%, were excluded. The evaluation of the functions of leisure and use classified items into use potential, use preference, use concentration, use diversification and use convenience. The results of the graded evaluation scores by space in use function, showed areas V and VI as Grade A, or 90% of the maximum score. Grade B, 70% of the maximum score, was given to Areas I and VII. Grade C, 50% of the maximum score, included Areas II, IV and VIII. Area III, graded lower the standard of 50%, was excluded. The study evaluated areas according to a common standard, classified spaces by proper functions into ecological spaces, environmentally-friendly use spaces and use spaces according to the standard of spatial distribution on the basis of the above results through a synthesis of grades of habitat function, leisure function and use. This offers ideas for the improvement of wildlife habitat and environment-friendly use functions by space.

• Ocean and Polar Research
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• v.26 no.3
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• pp.385-400
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• 2004

The Lago Sofia Conglomerate encased in the 2km thick hemipelagic mudstones and thinbedded turbidites of the Cretaceous Cerro Toro Formation, southern Chile, is a deposit of a gigantic submarine channel developed along a foredeep trough. It is hundreds of meters thick kilometers wide, and extends for more than 120km from north to south, representing one of the largest ancient submarine channels in the world. The channel deposits consist of four major facies, including stratified conglomerates (Facies A), massive or graded conglomerates (Facies B), normally graded conglomerates with intraformational megaclasts (Facies C), and thick-bedded massive sandstones (Facies D). Conglomerates of Facies A and B show laterally inclined stratification, foreset stratification, and hollow-fill structures, reminiscent of terrestrial fluvial deposits and are suggestive of highly competent gravelly turbidity currents. Facies C conglomerates are interpreted as deposits of composite or multiphase debris flows associated with preceding hyperconcentrated flows. Facies D sandstones indicate rapidly dissipating, sand-rich turbidity currents. The Lago Sofia Conglomerate occurs as isolated channel-fill bodies in the northern part of the study area, generally less than 100m thick, composed mainly of Facies C conglomerates and intercalated between much thicker fine-grained deposits. Paleocurrent data indicate sediment transport to the east and southeast. They are interpreted to represent tributaries of a larger submarine channel system, which joined to form a trunk channel to the south. The conglomerate in the southern part is more than 300 m thick, composed of subequal proportions of Facies A, B, and C conglomerates, and overlain by hundreds of m-thick turbidite sandstones (Facies D) with scarce intervening fine-grained deposits. It is interpreted as vertically stacked and interconnected channel bodies formed by a trunk channel confined along the axis of the foredeep trough. The channel bodies in the southern part are classified into 5 architectural elements on the basis of large-scale bed geometry and sedimentary facies: (1) stacked sheets, indicative of bedload deposition by turbidity currents and typical of broad gravel bars in terrestrial gravelly braided rivers, (2) laterally-inclined strata, suggestive of lateral accretion with respect to paleocurrent direction and related to spiral flows in curved channel segments around bars, (3) foreset strata, interpreted as the deposits of targe gravel dunes that have migrated downstream under quasi-steady turbidity currents, (4) hollow fills, which are filling thalwegs, minor channels, and local scours, and (5) mass-flow deposits of Facies C. The stacked sheets, laterally inclined strata, and hollow fills are laterally transitional to one another, reflecting juxtaposed geomorphic units of deep-sea channel systems. It is noticeable that the channel bodies in the southern part are of feet stacked toward the east, indicating eastward migration of the channel thalwegs. The laterally inclined strata also dip dominantly to the east. These features suggest that the trunk channel of the Lago Sofia submarine channel system gradually migrated eastward. The eastward channel migration is Interpreted to be due to tectonic forcing imposed by the subduction of an oceanic plate beneath the Andean Cordillera just to the west of the Lago Sofia submarine channel.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.95-106
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• 1996

The infestation rates and abundances of human infecting metacercariae (Clonorchis sinensis, Metcgonimus spry. , Centrocestus crmatus, Echinostoma hortense, Echinochusnus japonicw, Clinostomum complanctum) in freshwater fish were investigated at the three river areas - Taewhagang (river), Hyongsangang (river), Nakdonggang (river) - in Kyongsang-do and at four streams - Yonpungchon, Munsanchon, Kyonganchon, and Konjiamchon- in Kyonggi-do, Korea in 1994-1995. The fish caught at Taewhagang were heavily infested with metacercariae of Clonorchis sinensis and Centrocestw armctus. At Hyongsangang, Zncco platypus and Z. temmincki were moderately infested with metacercariae of C. crmctus. Chomanpo, at the basin of Nakdonggang, was still endemic for C. sinensis. In the fish caught at four streams of Kyonggi-do, metacercariae of C. sinensis exhibited the highest infestation rate and intensity out of 6 species of metacercariae. The infestation intensity of C. sinensis metacercariae in fish flesh was markedly different according to each division of flesh. The cause of this difference was conjectured as a result of larval behavior. The metacercariae of C. omnt5 were found in almost all parts, except scales and fins, of fish. The infestation rates and intensities of C. sinensis and C. armntus metacercariae in Taewhagang greatly increased as compared with those of previous reports . RhinoBobius bmnneus and Aconthorhone5 macropterus are newly recorded intermediate hosts of Echinostonn hortense. The reason of large differences from previous data was discussed and the standard method of metacercaria examination was proposed.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.245-262
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• 2013

We analyzed 29 surface sediment samples in five submarine volcanoes (TA12, TA19, TA22, TA25, and TA26) located in the southern part of the Tonga arc for trace elements and rare earth elements to investigate characteristics of the hydrothermal alteration of surface sediments. Based on analytical results of trace element and rare earth element (REE), surface sediments of TA12, TA19, and TA22 submarine volcanoes, which are located in the northern part of the study area, were very little or not influenced by hydrothermal fluids. In contrast, some stations of TA25 and TA26 submarine volcanoes were strongly affected by hydrothermal fluids. However, these two submarine volcanoes showed different features in element concentration in the sediments. Some stations of TA25 submarine volcano showed enrichment of Ni, Cu, Sn, Zn, Pb, Cr, Cd, Sb, W, Ba, Ta, Rb, Sr, and As, however, those of TA26 submarine volcano showed enrichment of Sn, Zn, Pb, Cd, Sb, Ba, Rb, and Sr. Stations which enriched trace elements were observed, enriched REEs were also observed. Average upper continental crust (UCC)-normalized REE patterns of the surface sediments generally showed low light REE (LREE) abundances and increased heavy REE (HREE) abundances. Eu enrichment was identified at several stations of TA25 and TA26 submarine volcanoes. In addition, enrichment of Ce was found at some stations of TA26 submarine volcano and these enrichment patterns were similar with hydrothermal fluid of near stations. Furthermore, TA25 and TA26 submarine volcanoes showed different enrichment characteristics of trace elements and REE. Trace elements were concentrated at TA25 submarine volcano. TA26 submarine volcano, on the other hand, observed highly enrichment of REE especially, Eu and Ce. As a result of the investigation, the characteristics and concentrations of REEs and trace elements in the surface sediments of each submarine volcano can be applied to identify hydrothermal alteration of sediments during exploration for hydrothermal deposits.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.96-115
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• 2017

Understanding effects of thermal pollution and acidification has long been a concern of aquatic ecologists, but it remains largely unknown in Korea. This study was performed to elucidate the effects of thermal wastewater effluent (TWE) and acid rain on water quality and attached algae in a small mountain stream, the Buso Stream, a tributary located in the Hantan River basin. A total of five study sites were selected in the upstream area including the inflowing point of hot-spring wastewater (HSW), one upstream site (BSU), and three sites below thermal effluent merged into the stream (1 m, 10 m and 300 m for BSD1, BSD2, and BSD3, respectively). Field surveys and laboratory analyses were carried out every month from December 2015 to September 2016. Water temperature ranged $1.7{\sim}28.8^{\circ}C$ with a mean of $15.0^{\circ}C$ among all sites. Due to the effect of thermal effluent, water temperature at HSW site was sustained at high level during the study period from $17.5^{\circ}C$ (January) to $28.8^{\circ}C$ (September) with a mean of $24.2{\pm}3.7^{\circ}C$, which was significantly higher than other sites. Thermal wastewater effluent also brought in high concentration of nutrients(N, P). The effect of TWE was particularly apparent during dry season and low temperature period (December~March). Temperature effect of TWE did not last toward downstream, while nutrient effect seemed to maintain in longer distance. pH ranged 5.1~8.4 with a mean of 6.9 among all sites during the study period. The pH decrease was attributed to seasonal acid rain and snow fall, and their effects was identified by acidophilic diatoms dominated mainly by Eunotia pectinalis and Tabellaria flocculosa during March and August. These findings indicated that water quality and periphyton assemblages in the upstream region of Buso Stream were affected by thermal pollution, eutrophication, and acidification, and their confounding effects were seasonally variable.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.445-466
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• 2017

Yeongdong area is located in the contact zone between central southeastern Ogcheon belt and Yeongnam massif, in which Cretaceous Yeongdong basin exists. Therefore, the study area has complex geological environment of various geological age and rock types such as Precambrian metamorphic rocks, age-unknown Ogcheon Supergroup, Paleozoic/Mesozoic sedimentary rocks, Mesozoic igneous rocks and Quaternary alluvial deposits. This study focuses on the link between the various geology and water type, and discussed the source of some major ions and their related water-rock interaction. For this study, the field parameters and ion concentrations for twenty alluvial/weathered and eighty bedrock aquifer wells were used. Statistical analysis indicates that there was no significant differences in groundwater quality between wet and dry seasons. Although various types were observed due to complex geology, 80 to 84 % of samples showed $Ca-HCO_3$ water type. Some wells placed in alluvial/weathered aquifers of Precambrian metamorphic and Jurassic granitic terrains showed somewhat elevated $NO_3$ and Cl concentrations. $Mg-HCO_3$ typed waters prevailed in Cretaceous Yeongdong sedimentary rocks. The deeper wells placed in bedrock aquifers showed complicated water types varying from $Ca-HCO_3$ through $Ca-Cl/SO_4/NO_3$ to $Na-HCO_3$ and Na-Cl type. Groundwater samples with $Na-HCO_3$ or Na-Cl types are generally high in F concentrations, indicating more influences of water-rock interaction within mineralized/hydrothermal alteration zone by Cretaceous porphyry or granites. This study revealed that many deep-seated aquifer had been contaminated by $NO_3$, especially prominent in Jurassic granites area. Based on molar ratios of $HCO_3/Ca$, $HCO_3/Na$, Na/Si, it can be inferred that Ca and $HCO_3$ components of most groundwater in alluvial/weathered aquifer wells were definitely related with dissolution of calcite. On the other hand, Ca and $HCO_3$ in bedrock aquifer seem to be due to dissolution of feldspar besides calcite. However, these molar ratios require other mechanism except simple weathering process causing feldspar to be broken into kaolinite. The origin of $HCO_3$ of some groundwater occurring in Cretaceous Yeongdong sedimentary rock area seems to be from dissolution of dolomite($MgCO_3$) or strontianite($SrCO_3$) as well.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.187-197
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• 2006

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency(EPA) was applied to the Yongdam Watershed to examine its applicability for loading estimates in watershed scale. It was run under BASINS (Better Assessment Science for Integrating point and Nonpoint Sources) program, and the model was validated using monitoring data of 2002 ${\sim}$ 2003. The model efficiency of runoff was high in comparison between simulated and observed data, while it was relatively low in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources and land uses intermixed in the watershed. The estimated pollutant load from Yongdam watershed for BOD, T-N and T-P was 1,290,804 kg $yr{-1}$, 3,753,750 kg $yr{-1}$ and 77,404 kg $yr{-1}$,respectively. Non-point source (NPS) contribution was high showing BOD 57.2%, T-N 92.0% and T-P 60.2% of the total annual loading in the study area. The NPS loading during the monsoon rainy season (June to September) was about 55 ${\sim}$ 72% of total NPS loading, and runoff volume was also in a similar rate (69%). However, water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. Overall, the BASINS/HSPF was applied to the Yongdam watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading in watershed scale.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.44-54
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• 2010

In this study, a comprehensive exploration and evaluation of washland candidate locations by means of field monitoring as well as spatial analysis in six major river system (Han, Nakdong, Nam, Geum, Youngsan, and Seomjin Rivers). Washland(in other words, river detention basin) is an artificial wetland system which is connected to streams or rivers likely to riverine wetlands. Major purpose of washland creation is to control floodings, water supply and purification, providence of eco-cultural space to human and natural populations. Characteristics and functions of riverine wetlands can be expected as well, thus it is believed to be an efficient multi-purpose water body that is artificially created, in terms of hydrology and ecology. Geographical information and field monitoring results for the washland candidate locations were evaluated in 2009, with respect to optimal location exploration, ecosystem connectivity and educational-cultural circumstances. A total of $269\;km^2$ washland candidate locations were found from spatial analysis (main channel of Rivers South Han, 71.5; Nakdong 54.1; Nam, 2.3; Geum, 79.0; Youngsan 46.4; Seomjin 15.7), and they tended to be distributed in mid- to lower part of the rivers to which tributaries are confluent. Field monitoring at 106 sites revealed that some sites located in the Rivers Nam and Geum is appropriate for restoration or artificial creation as riverine wetlands. Several sites in the Nakdong and Seomjin Rivers were close to riverine wetlands (e.g., Upo), habitats of endangered species (e.g., otters), or adjacent to educational facility (e.g., museums) or cultural heritages (e.g., temples). Those sites can be utilized in hydrological, ecological, educational, and cultural ways when evidence of detailed hydrological evaluation is provided. In conclusion, determination of washland locations in the major river basins has to consider habitat expansion as well as hydrological function (i.e. flood control) basically, and further utility (e.g. educational function) will increase the values of washland establishment.