• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.223-233
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• 2011

The aims of this study is about distribution characteristics of tidal coastal landforms, and that changing process in the Hampyeung Bay, which has a semi-enclosed bay like basin shape without inflow of stream, the mouth of open sea is narrow and forms with wide ends toward inland sea. The source of deposits are moved materials by tidal currents and from coastal slopes. Main landform elements of study area consist of tidal flat, tidal channels, intertidal sand bar, sea cliffs, and sea terrace. Tidal flats is classified with mud flat and mixed flat by grain size composition. Mud flats have developed at the shoreline area that tidal flat is closed to the continuity of gentle slope, and mixed flat developed at the foot of the sea cliffs and sea terraces. Quaternary deposits were identified in the coastal materials sedimented by the sea-level change. According to the analysis of grain size composition during last ten years, sands and silt has increased 2% and 6% respectively, clay has been decreased by 9%. The concaved tidal flats are colonized by salt plants. Areal changes of salt plants expanded near four times from 2.4km² at the year 2001 to 9.3km² at the year 2009. During the same periods, mean grain size became coarser from 6.5φ to 4.5φ at the salt plants area.

• Economic and Environmental Geology
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• v.34 no.2
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• pp.175-192
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• 2001

We have collected hydrogeochemical data of shallow groundwaters in the Uljin area located at eastern coastal area of Korea. Geostatistical analysis (ANOVA test, cluster analysis, and factor analysis) of the collected data sets was pert'onned, in order to evaluate both the spatial and/or temporal variation of water quality data and the groundwater contamination, as weJl as the principal reactions occurring in the aquifer. Results of the ANOVA test show that regional water chemistry are not significantly changed spatially in eight watersheds. However, some ions such as $Ca^{2+}$, $HCO_{3}^{-}$ and $SO_{4}^{2-}$ show a meaningful watershed variation. Water chemistry variation according to sampling time (season) is not shown, except for $SO_{4}^{2-}$. The cluster analysis shows that significant water chemistry variation is eXplained by the distance from the coast. Factor analysis indicates that the water chemistry is changed according to various factors as follows: in the order of decreasing importance, water-rock interaction (mainly, carbonate dissolution), sea-salt spraying, and then contamination by fertilizers and agrochemicals.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.327-334
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• 2011

Simulation of the trans-oceanic or trans-basin propagation of a tsunami is a computer-intensive task. This study demonstrates an effective and detailed visualization technique to deal with the vast amount of surface-elevation and velocity-field output. This high-definition visualization technique is used to present simulations of the 1960 and 2010 Chilean earthquake tsunamis and the 1983 Central East (Japan) Sea earthquake tsunami. This tsunami-visualization method using high-definition graphic animation is an appropriate tool to show detailed tsunami-propagation behavior over an ocean or coastal sea, as exemplified by the Pacific Ocean and East (Japan) Sea tsunami events.

• The Journal of the Petrological Society of Korea
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• v.23 no.3
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• pp.261-272
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• 2014

Over the last three decades, advances in AMS (Accelerator Mass Spectrometry) and Noble Gas Mass Spectrometer make various application of terrestrial cosmogenic nuclides (CNs) to wide range of earth surface sciences possible. Dating techniques can be divided into three sub-approaches: simple surface exposure dating, depth-profile dating, and burial dating, depending on the condition of targeted surfaces. In terms of Korean landscape view, CNs dating can be applied to fluvial and marine terrace, alluvial fan, tectonic landform (fault scarp and faulted surfaces), debris landforms such as rock fall, talus, block field and stream, lacustrine and marine wave-cut platform, cave deposits, Pliocene basin fill and archaeological sites. In addition, in terms of lithology, the previous limit to quartz-rich rocks such as granite and gneiss can be expanded to volcanic and carbonate rocks with the help of recent advances in CNs analysis in those rocks.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1165-1171
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• 2011

In this paper, we investigate hidden node problem to effectively utilize TV band devices(TVBDs) in the TV white space(TVWS), and also to protect digital television(DTV) service in Korea. Firstly, we classify the radio propagation environment into an urban area, a basin area, and a coastal area based on geographical characteristics. Thereafter, we measure and analyze local shape based hidden node attenuation at eight segmented positions in each geographic area. Because commercial buildings as well as residential and commercial buildings in Korea are located in closer proximity to each other than in other countries, hidden node margin should be more than 38 dB in order to safely protect DTV service in Korea.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.545-556
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• 2018

This study was conducted to estimate the deep percolation using numerical modeling and field observation data based on rainfall in Haean basin. Soil moisture sensors were installed to monitoring at 30, 60 and 90 cm depths in four sites (YHS1-4) and automatic weather station was installed to around YHS3. Soil moisture and meteorological data was observed from March 25, 2017 to March 25, 2018 and May 06, 2016 to May 06, 2018, respectively. Numerical analysis was performed from June to August, 2017 using the HYDRUS-1D. Average soil moisture contents were high to generally in YHS3 for 0.300 to $0.334m^3/m^3$ and lowest in YHS1 for 0.129 to $0.265m^3/m^3$ during the soil moisture monitoring period. The results of soil moisture flow modeling showed that field observations and modeling values were similar but the peak values were larger in the modeling result. Correlation analysis between observation and modeling data showed that r, $r^2$ and RMSE were 0.88, 0.77, and 0.0096, respectively. This show high correlation and low error rate. The total deep percolation was 744.2 mm during the period of modelling at 500 cm depth. This showed that 61.3% of the precipitation amount (1,214 mm) was recharged in 2017. Deep percolation amount was high in the study area. This study is expected to provide basic data for the estimation of groundwater recharge through unsaturated zone.

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.195-215
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• 2019

Geopark is a new system for development of the local economy through conservation, education, and tourism that is an area of scientific importance for the earth sciences and that has outstanding scenic values. The Hwaseong Geopark, the candidate for Korean National Geopark is composed of 10 geosites: Gojeongri dinosaur egg fossils, Ueumdo, Eoseom, Ddakseom, Goryeom, Jebudo, Baengmiri Coast, Gungpyeonhang, Ippado and Gukwado geosites. In this study, geosites, geoheritages, and geotrails of the Hwaseong Geopark were described in detail, and the value and significane as a geopark were also discussed. The geology of the Hwaseong Geopark area belonging to the Gyeonggi Massif consists of the Precambrian metamorphic and meta-sedimentary rocks, Paleozoic sedimentary and metamorphic rocks, Mesozoic igneous and sedimentary rocks, and Quaternary deposits, indicating high geodiversity. The Gojeongri Dinosaur Egg Fossils geosite, designated as a natural monument, has a geotrail including dinosaur egg nest fossils, burrows, tafoni, fault and drag fold, cross-bedding. Furthermore, a variety of infrastructures such as eco-trail deck, visitor center are well-established in the geosite. In the Ueumdo geosite, there are various metamorphic rocks (gneiss, schist, and phyllite) and geological structures (fold, fault, joint, dike, and vein), thus it has a high educational value. The Eoseom geosite has high academic value because of the orbicular texture found in metamorphic rocks. Also, various volcanic and sedimentary rocks belonging to the Cretaceous Tando Basin can be observed in the Ddakseom and Goryeom geosites. In the Jebudo, Baengmiri Coast, and Gungpyeonghang geosites, a variety of coastal landforms (tidal flat, seastacks, sand and gravel beach, and coastal dunes), metamorphic rocks and geological structures, such as clastic dikes and quartz veins can be observed, and they also provide various programs including mudflat experience to visitors. Ippado and Gukwado geosites have typical large-scale fold structures, and unique coastal erosional features and various Paleozoic schists can be observed. The Hwaseong Geopark consists of outstanding geosites with high geodiversity and academic values, and it also has geotrails that combine geology, geomorphology, landscape and ecology with infrastructures and various education and experience programs. Therefore, the Hwaseong Geopark is expected to serve as a great National Geopark representing the western Gyeonggi Province, Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.295-304
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• 2000

Vertical measurement of CTDT at about 30 min intervals and spatial surface temperature, salinity, and concentration of suspended particulate matters were conducted to elucidate the character of water column and the dispersal pattern in a floating ice-dominated fjord, Marian Cove, West Antarctica. Marian Cove showed two distinct water layers in terms of turbidity; 1) cold, fresh, and turbid surface plume in the upper 2 m,2) warm, saline, and relatively clean Maxwell Bay inflow between 15-45 m in water depth. Thermal melting of Maxwell Bay inflow and tidewater glacier/floating ices developed the surface mixed layer and the activity of floating ices cause Maxwell Bay inflow to be unstable. Due to the unstable water column, the development of Maxwell Bay inflow and subsequent surface plume are not influenced by tidal frequency. Coastal current generated by strong northwesterly wind may extend warm, saline, and turbid surface plume into the central part of the cove along the northern coast via the western coast of Weaver Peninsula. Terrigenous sediments of meltwaters from the glaciated ice cliffs near the corner of tidewater glacier and some coasts enter into the cove and their dispersion depends upon the hydrographic regimes (tide, wind, wave etc.). At the period of spring tide, the strong wind stress with the northwesterly wind direction reserve suspended sediment-fed surface plume and so allow the possibility of deposition of terrigenous sediments within the basin of cove.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.679-688
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• 2013

This study figured out the influential factors of region-based characteristic factors in our country upon asthmatic occurrence. Research subjects were 2,266,451 people who were confirmed the diagnosis of asthma (J45~J46) among patients in national health insurance for the year in 2010. The influence in each of factors upon the asthmatic occurrence was analyzed through hierarchical regression after comparing difference in asthmatic occurrence by basic local government. As a result of hierarchical regression, the whole asthmatic occurrence had significant difference in infants ratio, $SO_2$,Temperature, basin and dam area. The asthmatic occurrence had significant difference in subjective awareness of health level, $SO_2$, basin and dam area. A case of asthmatic occurrence had significant difference in infants ratio, temperature, $NO_2$ and coastal area. Diverse characteristic factors by region were indicated to have influence upon the asthmatic occurrence by causing or weakening asthma through mutually complex action. Accordingly, a region-based customized environmental health measure will need to be arranged that infants and elderly people, who are vulnerable classes, can be protected and prevented from harmful environment of asthma.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.453-460
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• 2008

This study conducted an analysis of plant species composition and vegetation at sea cliffs of the uninhabited islets off Ganghwa-gun by applying discontinuous classification method & continuous ordination method of species composition table by correlation. The analysis results are as follows: First, the plant showing the highest appearance frequency was Parthenocissus tricuspidata Planch.(58.3%), followed by Carpinus coreana Nak., Viburnum carlesii Hemsl. and Kalopanax septemlobus Koidz.(37.5%,respectively). As for a plant community, it was found that it consisted of Quercus mongolica community, Tilia mandshurica community, Carpinus coreana community, Sorbus alnifolia community and Pinus thunbergii community; as for the community distribution classified by individual islet, it was revealed that Quercus mongolica community appeared at Sosongdo and Bunjido; Tilia mandshurica community at Sosongdo and Daesongdo; Carpinus coreana community appeared at Woodo, Suribong and Bido; Sorbus alnifolia community at Susido, Sosongdo and Daesongdo, and Pinus thunbergii community at Seokdo and Woodo, respectively. The plant similarity classified by uninhabited islet was found to be the highest at Sosongdo and Daesongdo. This research judged the reason why the typical grassland community of coastal cliffs did not join these islets to be environmental conditions of rock landform where there exists almost no surface soil at most sea cliffs; thus, more detailed study on this was required.