• Geomechanics and Engineering
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• v.7 no.1
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• pp.105-131
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• 2014

In this paper, the effects of variability of smear zone characteristics induced by installation of prefabricated vertical drains on the preloading design are investigated employing analytical and numerical approaches. Conventional radial consolidation theory has been adopted to conduct analytical parametric studies considering variations of smear zone permeability and extent. FLAC 2D finite difference software has been employed to conduct the numerical simulations. The finite difference analyses have been verified using three case studies including two embankments and a large-scale laboratory consolidometer with a central geosynthetic vertical drain. A comprehensive numerical parametric study is conducted to investigate the influence of smear zone permeability and extent on the model predictions. Furthermore, the construction of the trial embankment is recommended as a reliable solution to estimate accurate smear zone properties and minimise the post construction settlement. A back-calculation procedure is employed to determine the minimum required waiting time after construction of the trial embankment to predict the smear zone characteristics precisely. Results of this study indicate that the accurate smear zone permeability and extent can be back-calculated when 30% degree of consolidation is obtained after construction of the trial embankment.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.113-128
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• 2014

Jeju Special Self-Governing Province has the natural assets resulting in UNESCO World Biosphere Reserve, World Heritage Listed and World Geopark Certification, so the principle of 'Conservation First Development Later' has been set up for the vision of environmental policy to preserve these assets. This case study has been carried out to investigate the realization of the principle of 'Conservation First Development Later' for the development projects performed environmental impact assessment from 1994 to 2012 in Jeju Province, using geographic information systems(GIS). The Jeju Province has its own ordinance to consult and operate an environmental impact assessment(EIA) system. In particular, the conservation area, such as, Absolute/Relative Conservation Area and Underground Water, Ecosystem and View Conservation Zone, has been assigned and managed specially to conserve the natural environment. The 179 projects has been performed EIA for last 18 years in Jeju Province, and then the Absolute Conservation Area has been included in 22 projects and the Relative Conservation Area has been included in 34 projects. However, the 2 projects only have included the Absolute Conservation Area for 7 years after 2005. This result suggests that the application of the principle for the Absolute Conservation Area is strengthened gradually. On the other hand, the 17 projects and the 24 projects have included the Underground Water Conservation Zone assigned grade 1 and 2, respectively, and the number has been increasing after 2004. The results show that it needs to strengthen the application of the principle for this Zone. And the Ecosystem Conservation Zone assigned grade 1 and 2 have been included in 1 project and 9 projects, respectively. It is considered from this result that the principle is realized successfully for the Ecosystem Conservation Zone. In addition, it could be known that the principle is applied well for the View Conservation Zone, in this study.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.271-281
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• 2019

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.313-316
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• 2007

Ground-penetrating radar (GPR) is an effectiveness tool for imaging spatial distribution of hydrogeologic parameters. An artificial groundwater recharge test has been conducted in Nagaoka City in Japan, and time-lapse crosshole GPR data were collected to monitor infiltration processes in a vadose zone. Since radiowave velocities in a vadose zone are largely controlled by variations in water content, the increase in traveltimes is interpreted as an increase in saturation in the test zone. We use a finite-difference time-domain method in two-dimensional cylindrical coordinates to simulate field results. Numerical modeling successfully reproduces the major feature of velocity changes in the filtration process.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.39-56
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• 2021

The seed zone is a map that describes the areas where plant material can be transferred with little risk for properly adapting to a new location. The seed zone study is largely divided into studies based on genetic data and studies based on climatic data. Can be. This study was conducted to establish a temporary domestic seed zone applicable to the entire Korean Peninsula and evaluate its possibility based on the US climate-based seed zone establishment methodology. The temporary seed zone was constructed in the same way as the US case by superimposing the data obtained by dividing the winter minimum temperature into 12 grades and the data obtained by dividing the annual heat: moisture index into 6 grades. As a result of the analysis, 65 temporary seed zones were formed throughout the Korean Peninsula, and the areas of the seed zones representing the smallest and largest areas were 3.0km² and 29,423.0km², respectively, and it was confirmed that they had an average size of about 5,064.9km². Temporary seed zones applied in Korea show a pattern of changes in temperature according to the relatively horizontal forest zone, and it was confirmed that the area where the Baekdu-daegan ecological axis is located has a tendency to show lower dryness than other areas. This study applied the US climate-based seed zone methodology in Korea as a pilot, and confirmed the climatic similarity across the Korean Peninsula. Furthermore, it is expected to provide an optimal seed map that improves the success rate of restoration in the future by revising the seed zone grade suitable for the domestic environment in consideration of the results of this study and the possibility of seed adaptation to the field survey and environmental space.

• Journal of Environmental Science International
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• v.31 no.4
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• pp.357-363
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• 2022

In this study, we installed a weather observation tower tailored to the intertidal zone and established an intertidal weather observation system capable of real-time monitoring through a wireless network. This provided weather observation data representing the meteorological characteristics of the intertidal zone. To optimize this system in the future, we present practical directions for the development of observation equipment and for the data management and sharing, and we contribute to establishing the infrastructure.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1027-1038
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• 2022

The intertidal zone has both land and marine characteristics and shows complex weather environments. These characteristics are suited for studying climate change, energy balance and ecosystems, and may play an important role in coastal and marine weather prediction and analysis. This study was conducted at Odo Island, approximately 300m from the mainland in Yeosu. We built a weather observation system capable of real-time monitoring on the mud flat in the intertidal zone and measured actual weather and marine data. Weather observation was conducted from April to June 2022. The results showed changes in air temperature and water temperature with changes in the tide level during spring. Correlation analysis revealed characteristic changes in air temperature and water temperature during the day and night, and with inundation and exposure.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.519-535
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• 1999

Precambrian metasedimetay rocks in the Sunchang Shear Zone (so-called Seologri and Yongamsan Formation) consist of black slate, phylite, mica schistm quartzite and rarely calc schist. The metamorphic rocks in the area have undergone at least three stages of metamorphism, which are two prograde (M1 and M2) and one contact metamorphism (M3). The metamorphism which made the most prevailing mineral assemblages in the area, is M2 stage metamorphism. The metamorphic grade of M2 methamorphism in metapelites increases from the Chlorite zone through Biotituzone, Garnet zone to Staurolite zone. The M1 stage metamorphism is recognized by kyanite and sillimanite pressure type regional metamorphism. The M3 stage methamorphism is represented in the contact boundary, which area is the chlorite zone and biotite zone near the Sunchang foliated granite and the namwon granite. The M3 stage methamorphism is characterized by andalusite bearing mineral assemblages. The peak temperature condition of M2 metamorphism estimated from coexising garnet and biotite (Kretz, 1990) is 518~598$^{\circ}C$.

• Korean Institute of Interior Design Journal
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• v.27 no.1
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• pp.12-20
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• 2018

After the "Landscaping Law" was enacted in 2007 Korea, national and local governments has been responding swiftly by seeking various methods. Seoul Metropolitan City and other municipalities have established "Seoul Coloring and Systematization" project, which analyzes and extracts the humanities, humanities and natural environments in 2007 as an opportunity to recognize the importance of environmental color. However, it is necessary to slightly supplement the color scheme created by the observer's concept. In this way, you have to find the color of the environment in a city where real life takes place. The city's environmental color has the concept of "walking" as the basic human behavior. Because the average speed is 4km, it differs from that of a vehicle that travels more than 60km per hour. Also, most of the frontage zone is used except for special cases. Therefore the characteristics of the environmental color and frontage zone on the road side were concluded in this paper as Single Type, Connection Type, and Extension Type. In addition, the principle of environmental color of city was established by the change of texture according to space of time and the characteristics of urban scale, and new media characteristics were found in various interactions. The results of this study suggest an environmental coloring strategy for workability such as hue continuity, hue harmonization and integrated design.