• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.1-8
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• 2008

The objectives of this study were to compare nutrient natural input between thinned and unthinned natural hardwood stands at Mt. Joongwang, Pyongchang-gun, Gangwon-do. Throughfall, stemflow, A-layer and B-layer soil water as well as litterfall were sampled at two-week intervals during the period of June to October from 2002 to 2004. The amount of rainfall interception in thinned and unthinned natural hardwood stands was as 12% and 18%, respectively. The results indicated that there was no difference in annual nutrient input by rainfall between thinned and unthinned stands. $Na^+$, $Cl^-$ and $SO_4{^{2-}}$ concentrations of A-layer soil water in the unthinned stand were higher than those in the thinned stand. In the B-layer soil water, $Ca^{2+}$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$ concentrations in the unthinned stand were higher than those in thinned stand. Mean annual litterfall input was $2,706kg\;ha^{-1}$ in unthinned stand and $2,589kg\;ha^{-1}$ in thinned stand. Total-N input from litterfall was $50.28kg\;ha^{-1}yr^{-1}$ in the unthinned stand and $36.81kg\;ha^{-1}yr^{-1}$ in the thinned stand, while there was no difference in exchangeable cation input from litterfall between thinned and unthinned stands. Thus, the difference in nutrient inputs except for N by throughfall, stemflow and litterfall between the two stands was not influenced by thinning.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.444-450
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• 2012

The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.471-482
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• 2008

This study was carried out to investigate the contamination characteristics of surface water, soil water and groundwater around and in antimony waste landfill site in Wonsung-ri, Yeonki-kun, Chungnam. The waste disposed in the study was excavated and transported to the other site in several years ago. For this study, we collected 35 water samples including groundwater, soil water and surface in the study site and also collected 2 groundwater samples from a comparison site. The data of chemical analysis of soil water samples show the antimony concentration of $48.75{\sim}74.81\;ppb$, which is much higher than groundwater in a comparison site and is highly excess than regulation level for a drinking water of some advanced countries. A relatively high antimony concentration was detected in three stream water samples nearby landfill site and two groundwater samples. Fe and Mn contents in soil water and stream water were measured as maxium 6.5 mg/L and 7.3 mg/L, respectively. Although other heavy metals of water samples in the study site are higher concentration than water sample of comparison site, their absolute levels are lower than regulation level for a drinking water. The chemical data of water samples are plotted widely from Ca - $HCO_3$ type to Ca - ($Cl +SO_4+NO_3$) type. Some groundwater show high contents of potassium and nitrate, which would come from fertilizer and sewage. Conclusively, some heavy metals including antimony have been still remained under the soil surface of the landfill site in the past. These metals have leaked out into nearby stream and groundwater system, and threaten the ecology, crops and the health of residents in this site. Therefore, the government have to prepare the strategy to prevent the diffusion of heavy metals into aquatic environment and have to process the reclamation work for contaminated site. It is also necessary to make a regulation level of the antimony concentration for a drinking water and soil environment in Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.128-136
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• 2011

To monitor and predict the change of coastal environment according to the construction of Saemangeum sea dyke and the development of land reclamation, we have done real-time and periodic ocean observation and numerical simulation since 2002. Saemangeum coastal environmental data can be largely classified to marine meteorology, ocean physics and circulation, water quality, marine geology and marine ecosystem and each part of data has been generated continuously and accumulated over about 10 years. The collected coastal environmental data are huge amounts of heterogeneous dataset and have some characteristics of multi-dimension, multivariate and spatio-temporal distribution. Thus the implementation of information system possible to data collection, processing, management and service is necessary. In this study, through the implementation of Saemangeum coastal environmental information system using geographic information system, it enables the integral data collection and management and the data querying and analysis of enormous and high-complexity data through the design of intuitive and effective web user interface and scientific data visualization using statistical graphs and thematic cartography. Furthermore, through the quantitative analysis of trend changed over long-term by the geo-spatial analysis with geo- processing, it's being used as a tool for provide a scientific basis for sustainable development and decision support in Saemangeum coast. Moreover, for the effective web-based information service, multi-level map cache, multi-layer architecture and geospatial database were implemented together.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.213-219
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• 2011

Transient/time-domain electromagnetic (TEM) soundings were carried out on reclaimed land, since the TEM sounding has good resolution of a conductive and thin overburden. The reclamation material is marine clay dredged from the seafloor, which is currently undergoing consolidation in the upper part of the dredged layer. The conductivity of the marine-origin clay is generally more than 0.3 S/m. The aim of the TEM sounding was to determine the depths of weathered and soft rocks overlain by thick and conductive overburden. The TEM responses were measured at delay times of 0.050-20.575 ms with a $30{\times}30$ m coincident loop array. Data from the TEM inversion and core logging indicate that the resistivities of the conductive overburden are less than 2 ${\Omega}$-m, while those of the weathered and soft rocks are 10-20 and 70 ${\Omega}$-m, respectively. The depth to weathered rock is 26-58 m and the depth to soft rock is 46-75 m.

• Journal of Korea Water Resources Association
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• v.50 no.6
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• pp.387-395
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• 2017

Sea level rise, accompanied by climate change, is expected to exacerbate seawater intrusion in the coastal groundwater system. As the salinity of saturated groundwater increases, salinity can increase even in the unsaturated soil above the groundwater surface, which may cause crop damage in the agricultural land. The other adverse impact of sea level rise is reduced unsaturated soil thicknesses. In this study, a composite model to assess impacts of sea level rise in coastal agricultural land is proposed. The composite model is based on the combined applications of a three dimensional model for simulating saltwater intrusion into the groundwater and a vertical one dimensional model for simulating unsaturated zone flow and transport. The water level and salinity distribution of groundwater are calculated using the three dimensional seawater intrusion model. At some uppermost nodes, where salinity are higher than the reference value, of the 3D mesh one dimensional unsaturated zone modeling is conducted along the soil layer between the ground water surface and the ground surface. A particular location is judged salinized when the concentration at the root-zone depth exceeds the tolerable salinity for ordinary crops. The developed model is applied to a hypothetical agricultural reclamation land. IPCC RCP 4.5 and 8.5 scenarios were used as sea level rise data. Results are presented for 2050 and 2100. As a result of the study, it is predicted that by 2100 in the climate change scenario RCP 8.5, there will be 7.8% increase in groundwater saltwater-intruded area, 6.0% increase of salinized soil area, and 1.6% in increase in water-logging area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.35-43
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• 2003

Recent geomorphological changes and late Quaternary depositional sequences of Gwangyang Bay are studied based on bathymetric maps, surface sediments, and seismic profiles. As a result of the reclamation of coastal area for an industrial complex construction, the coastline of Gwangyang Bay has rapidly been changed and the area of it has now been reduced by about 25 ％ in the last 30 years. In addition, the bottom topography is actively modified by dredging for navigation channels. In surfical sediment distribution, the western part of Gwangyang Bay is dominated by mud facies, whereas the eastern part of the Bay is dominated by sand-mud mixing facies. Depositional sequences above the basement are divided into two units: Unit I in upper layer and Unit II in lower one. These depositional units are unconformably bounded by middle reflector-M. Unit II, mostly occupying the channel areas, is interpreted as fluvial-origin deposits during sea-level lowstand. Unit I typically shows a progradational pattern from the Seomjin River mouth to the Yeosu Strait, which is interpreted as deltaic deposits supplied from the Seomjin River during the Holocene sea-level highstand. The shallow gas within the sediments Is widely distributed in most area, and locally exposed onto the sea-bed due to dredging.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.90-103
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• 2015

The agricultural soil, meets soil environmental standards whereas agricultural product from the same soil does not meet permissible level of contaminants, is identified in the vicinity of the abandoned mine in Korea. This study estimated the stabilization efficiency of Cd and Pb using limestone through the flood pot test for this kind of agricultural paddy soil. We had the concentration of the monitored contaminants in soil solution for 4 months and analyzed fractionations in soil and concentrations in rice plant. In soil solution of plow layer, the reductive Mn had been detected constantly unlike Fe. The concentrations of Mn in limestone amended soil was relatively lower than that in control soil. This reveals that the reductive heavy metals which become soluble under flooded condition can be stabilized by alkali amendment. This also means that Cd and Pb associated with Mn oxides can be precipitated through soil stabilization. Pb concentrations in soil solution of amended conditions were lower than that of control whereas Cd was not detected among all conditions including control. In contaminants fractionation of soil analysis, the decreasing exchangeable fraction and the increasing carbonates fraction were identified in amended soil when compared to control soil at the end of test. These results represent the reduction of contaminants mobility induced by alkali amendment. The Cd and Pb contents of rice grain from amended soil also lower than that of control. These result seems to be influenced by reduction of contaminants mobility represented in the results of soil solution and soil fractionation. Therefore contaminants mobility (phytoavailability) rather than total concentration in soil can be important factor for contaminants transition from soil to agricultural products. Because reduction of heavy metal transition to plant depends on reduction of bioavailability such as soluble fraction in soil.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.39-50
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• 2003

This study aims to figure out water quality impacts due to sudden disturbances of sediments during dike construction in land reclamation for the northern part of the Siwhaho Lake where heavily deteriorated settlements from upstream loadings are outstanding. We exploit a 3-D water quality model CE-QUAL-ICM combined with a hydrodynamic model TIDE3D. Simulations are done accounting water-sediment interaction in a 4-$\sigma$ layers. Long-term simulation for 1-year shows that bottom layers around the disturbance location are only affected and marks very high concentration. Complete vertical mixing appears at least 5km apart to downward due to complex effects of geometry, bathymetry and river inflows. It should be addressed that existing condition of the Siwhaho Lake stands for high concentration of COD and TP in winter and spring due to relatively high incoming loadings, however the effect of sediment disturbances yields reverse phenomena, i.e., impacts of dike construction arise greatly in summer and fall. Refined grid system consisting of 150m${\times}$150m rectangular grid, which is doubled system compared to previous study (Suh et al.,2002), gives affordable results by reducing flux differences through a cell especially in front of gate.

• Journal of architectural history
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• v.19 no.3
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• pp.7-29
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• 2010

The form of the Wangheungsa Temple's wooden pagoda site is that of the traditional form of the wooden pagodas constructed during the Baekjae Period. Likewise, it is an important ruin for conducting research on the form and type of the wooden pagodas constructed during the Baekjae Period. In particular, the method used for the installation of the central pillar's cornerstone is a new technique. The purpose of this research is to restore the ruin of the Wangheungsa Temple's wooden pagoda of the Baekjae Period that remains at the Wangheungsa Temple's wooden pagoda site. Until now, research conducted on the wooden pagoda took place mostly centered on the Hwangryongsa Temple's wooden pagoda. Meanwhile, the reality concerning Baekjae's wooden pagoda is one in which there were not many parallel cases pertain to the design for restoration. This research paper wants to conduct academic examination of the Wangheungsa Temple's wooden pagoda to organize the intention of design and design process in a simple manner. This research included review of the Baekjae Period's wooden pagoda related ruins and the review of the existing wooden pagoda ruin to analyze the wooden pagoda construction technique of the era. Then, current status of the Wangheungsa Temple's wooden pagoda site is identified to define the characteristics of the wooden pagoda, and to set up the layout format and the measure to estimate the size of the wooden pagoda in order to design each part. Ultimately, techniques and formats used for the restoration of the wooden pagoda were aligned with the wooden pagoda of the Baekjae Period. Basically, conditions that can be traced from the current status of the Wangheungsa Temple site excavation using the primary standards as the standard. Wangheungsa Temple's wooden pagoda was designed into the wooden pagoda of the Baekjae's prosperity phase. The plane was formed into $3{\times}3$ compartments to design into three tier pagoda. The height was decided by factoring in the distance between the East-West corridors, size of the compartment in the middle, and the view that is visible from above the terrace when entering into the waterway. Basically, the origin of the wooden structure format is based on the Goguryeo style, but also the linkage with China's southern regional styles and Japan's ancient wooden pagoda methods was factored in. As for the format of the central pillar, it looks as if the column that was erected after digging the ground was used when setting up the columns in the beginning. During the actual construction work of the wooden pagoda, central pillar looks as if it was erected by setting up the cornerstone on the ground. The reason that the reclaimed part of pillar that use the underground central cornerstone as the support was not utilized, was because the Eccentric Load of the central pillar's cornerstone was factored in the state of the layers of soil piled up one layer at a time that is repeated with the yellow clay and sandy clay and the yellow clay that were formed separately with the $80cm{\times}80cm$ angle at the upper part of the central pillar's cornerstone was factored in as well. Thus, it was presumed that the central pillar was erected in the actual design using the ground style format. It is possible to presume the cases in which the reclaimed part of pillar were used when constructed for the first time, but in which central pillar was installed later on, after the supplementary materials of the underground column is corroded. In this case, however, technique in which soil is piled up one layer at a time to lay down the foundation of a building structure cannot be the method used in that period, and the reclamation cannot fill up using the $80cm{\times}80cm$ angle. Thus, it was presumed that the layers of soil for building structure's foundation was solidified properly on top of the central pillar's cornerstone when the first wooden pagoda construction work was taking place, and that the ground style central pillar was erected on its upper part by placing the cornerstone once again. Wangheungsa Temple's wooden pagoda is significant from the structure development aspect of the Korean wooden pagodas along with the Hwangryongsa Temple's wooden pagoda. Wangheungsa Temple's wooden pagoda construction technique which was developed during the prosperity phase of the Baekjae Period is presumed to have served as a role model for the construction of the Iksan Mireuksa Temple's wooden pagoda and Hwangryongsa Temple's wooden pagoda. With the plan to complement the work further by excavating more, the basic wooden pagoda model was set up for this research. Wangheungsa Temple's wooden pagoda was constructed as at the Baekjae Kingdom wide initiative, and it was the starting point for the construction of superb pagoda using state of the art construction techniques of the era during the Baekjae's prosperous years, amidst the utmost interest of all the Baekjae populace. Starting out from its inherent nature of enshrining Sakyamuni's ashes, it served as the model that represented the unity of all the Baekjae populace and the spirit of the Baekjae people. It interpreted these in the most mature manner on the Korean peninsula at the time.