• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.31-38
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• 2001

An illegal landfill In Korea was evaluated in a view of environmental quality to figure out reusing the area. The sampling spots were selected at a point in the landfill and three points in it's around area(two points in a paddy soils and one in a farm field). The eleven pollutants regulated in the Korean Soil Environmental Preservation Act (KSEPA) were analysed from the soil sample with the method of the KSEPA. As the results of the analysis the level of concentration with most samples indicated the requirement of the KSEPA. The concentration of soil samples met the standard: however, some pollutants in the ground water and leachate showed higher concentration than that of the requirement. Therefore, we must consider the treatments of the pollutants in the ground water and leachate when designing this landfill area for reusing.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.47-56
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• 2013

PURPOSES: This study is to evaluate a ground water level effect on frost heaving in road pavements. METHODS: The effects of water table on frost heaving in pavement systems were evaluated from the mechanical analysis using FROST program. The input parameters and boundary conditions were determined by considering climates, pavement sections, and material properties specially subgrade soil types in Korea. RESULTS: When the water table located above the freezing depth, amount of frost heaving caused by freezing the water in pavement itself was big enough to damage in pavement system, although pavement system consists of fully non-frost-susceptible materials with sufficient thickness of anti-freezing layer. The amount of frost heaving was decreased rapidly with increasing the distance between the water table and freezing depth. CONCLUSIONS: It was concluded that there is no engineering problems related with frost heaving in practical sense when the distance between freezing depth and water table is over 1.5m for having subgrade soils less than 50% of #200 sieve passing to meet specification on quality control in Korea.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.195.2-195.2
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• 2011

The borehole heat exchanger of Geothermal Heat Pump (GHP) system should be sustainable and cost effective for long term operation. To guaranty the performance of the system thermal Response Tests (TRTs) with simple recommended procedures have been applied in many countries. Korea government developed a standard TRT procedure in order to control the quality on GHP projects. In the TRT procedure interpretation method has a rule that data set has to be interpreted by the line source model(LSM). The LSM employes some assumptions that surrounding medium is homogeneous and the line source is infinite and constant heat flux, however real ground condition is unisotropic and heterogeneous, and showing regional or local ground water flows in many cases. We need to develope improved evaluation models to estimate accurate ground thermal conductivity with respect to geological and influence of ground water because current TRT standard test procedure has limitations to be applied for every locations and system. This study surveyed the uncertainty of the thermal parameters from the interpretation method considering different evaluation period. The interpretation of 208 TRT data sets represents limitations of LSM application that some obtained ground thermal conductivities are statistically unstable and convergence time of ground thermal conductivity over test period shows trends responding the length of test period. This evaluation study will be helpful to provide some effective procedure for the thermal parameter estimation and to complement current TRT standard procedure.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.561-566
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• 2009

Alluvium is sedimentary stratum and composed of gravel, sand, silt, clay. Permeability of alluvium is the higher. If alluvium have lots of aquifer, will be of great use heat source and heat sink of heat pump. Alluvium aquifer contain the thermal energy of surrounding ground. Also geothermal heat pump using alluvium aquifer reduce expenses than general geothermal heat pump, because geothermal heat pump using alluvium aquifer make use of single well. In this study geothermal heat pump using alluvium aquifer was installed and tested for a building. The heat pump capacity is 30USRT. Temperature of ground water is in $12{\sim}17^{\circ}C$ annually and the quality of the water is as good as living water. The heat pump cooling COP is 4.4 ~ 4.7. The system cooling COP is 3.25 ~ 3.6. This performance is as good as BHE type ground source heat pump.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.363-370
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• 1999

Remotely sensed data is regarded as a potentially effective data source for the measurement of water quality and for the environmental change of water bodies. In this study, we measured the spectral reflectance by using multi-spectral image of low resolution camera(LRC) which will be loaded in the OSMI multi-purpose satellite(KOMPSAT) scheduled to be launched on 1999 to use the data in analyzing water pollution. We also investigated the possibility of extraction of water quality factors in water bodies by using remotely sensed low resolution data such as NOAA/AVHRR. In this study, Shiwha-District and Sang-Sam Lake was set up as the subject areas for the study. In this part of the study, we measured the spectral reflectance of the water surface to analyze the radiance of the water bodies in low resolution spectral band and tried to analyze the water quality factors in water bodies by using radiance feature from another remotely sensed data such as NOAA/AVHRR. As the method of this study, first, we measured the spectral reflectance of the water surface by using SFOV( Single Field of View) to measure the reflectance of water quality analysis from every channel in LRC spectral band(0.4~O.9${\mu}{\textrm}{m}$). Second, we investigated the usefulness of ground truth data and the LRC data by measuring every spectral reflectance of water quality factors. Third, we analyzed water quality factors by using the radiance feature from another remotely sensed data such as NOAA/AVHRR. We carried out ratio process of what we selected Chlorophyll-a and suspended sediments as the first factors of the water quality. The results of the analysis are below. First, the amount of pollutants of Shiwha-Lake has been increasing every you since 1987 by factors of eutrophication. Second, as a result of the reflectance, Chlorophyll-a represented high spectral reflectance mainly around 0.52${\mu}{\textrm}{m}$ of green spectral band, and turbidity represented high spectral reflectance at 0.57${\mu}{\textrm}{m}$. But suspended sediments absorbed high at 0.8${\mu}{\textrm}{m}$. Third, Chlorophyll-a and suspended sediments could have a distribution chart as a result of the water quality analysis by using NOAA/AVHRR data.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.1-9
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• 2015

A combined treatment system using multiple source water is becoming important as an alternative to conventional water supply for small-scale water systems. In this research, combined water treatment systems were investigated for simultaneous use of multi-source water including rainwater, ground water, river water, and reclaimed wastewater. A laboratory-scale system was developed to systematically compare various combinations of water treatment processes, including sand filtration, microfiltration (MF), granular activated carbon (GAC), and nanofiltration (NF). Results showed that the efficiency of combined water treatment systems was affected by the quality of feed waters. In addition, a simply approach based on the concept of linear combination was suggested to support a decision-making for the optimum water treatment systems with the consideration of final water quality.

• Journal of Environmental Science International
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• v.23 no.8
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• pp.1395-1407
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• 2014

Coal seam gas (CSG) production involves extracting methane from coal seams with ground water which is so called a primary by-product of this process, and is often rich in salts and other constituents. The predicted large volume and variable quality of this water make water management a topic associated with CSG production. In the past, the amount of this water used to be pumped into the vacant aquifer, or into the river during the life of individual production wells. Australian government make a strategies for management and beneficial use of the water. From this point of view, a detailed assessment has not been undertaken, it is necessary for water resource production to analysis the "Coal Seam Gas Water (CSG Water) Management Policy Study" published in Queensland, Australia.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.67-92
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• 1997

Tap water should be shown the complexity of measures neccessary to secure water quality, especially with respect to drinking and bathing. Designated reservoirs Paldang and Daechung as the Special Environment Protection Areas to regulate new pollution sources and to facilitate construction of wastewater treatment facilities. In this country, 91% of total drinking water resource, consist of 66% stream water, 25% dam water, 7% dune flitrate, 1% each of spring and ground water, are from the surface water. The total volume of annual mean water resources due to precipitation. Over 8% of the total resources are class III as shown in the table., eapecially the water quality of downstream of Nakdong and Yeongsan river are getting worse due to continued economic and social development.

• Geomechanics and Engineering
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• v.16 no.6
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• pp.635-642
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• 2018

Braced excavation systems are commonly required to ensure stability in construction of basements for shopping malls, underground transportation and other habitation facilities. For excavations in deposits of soft clays or residual soils, stiff retaining wall systems such as diaphragm walls are commonly adopted to restrain the ground movements and wall deflections in order to prevent damage to surrounding buildings and utilities. The ground surface settlement behind the excavation is closely associated with the magnitude of basal heave and the wall deflections and is also greatly influenced by the possible groundwater drawdown caused by potential wall leakage, flow from beneath the wall, flow from perched water and along the wall interface or poor panel connections due to the less satisfactory quality. This paper numerically investigates the influences of excavation geometries, the system stiffness, the soil properties and the groundwater drawdown on ground surface settlement and develops a simplified maximum surface settlement Logarithm Regression model for the maximum ground surface settlement estimation. The settlements estimated by this model compare favorably with a number of published and instrumented records.

• Journal of Environmental Science International
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• v.25 no.3
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• pp.337-343
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• 2016

The present study aimed to determine the influence of various root restriction media on seedling quality and early growth of strawberry after transplanting. The root activity of the seedlings, measured 20 days after fixation, was considerably higher (0.096, 0.090, and $0.063mg{\cdot}g^{-1}{\cdot}h^{-1}$ at 420, 450, and 480 nm, respectively) in expanded rice hull (ERH) treatment than in the sandy loam and loamy sand treatments. The volumetric water content (VWC) of the root media tested across 3 irrigation regimes (15 d, 30 d, 45 d) in the nursery field was highest in sandy loam (65.0-66.8%), followed by 59.4-61.3% in loamy sand and 38.6-45.3% in ERH. When growth parameters of runner plantlets were compared, ERH treatment was found to result in the highest crown thickness and fresh weights of root and above-ground parts. This had a favorable influence on above-ground tissue growth after transplanting to plastic house soil. As mentioned above, ERH treatment resulted in the highest seedling quality and early growth after transplanting. The results of this study would serve as useful on-site data for the production of high-quality strawberry seedlings.