• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.127-145
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• 1998

Unlike water or air quality standards that have been established by legislation using potential human health impact as the primary criterion, soil quality depends on the soils primary function and its relevant environmental factors, which is much more site- and soil specific. A properly characterized soil quality assessment system should serve as an indicator of the soil capacity to produce safe and nutritious food, to enhance human and animal health, and to overcome degrative processes. For our proposed example, a high quality soil with regard to maintaining an adequate soil productivity as a food production resources must accommodate soil and water properties, food chain, sustainability and utilization, environment, and profitability, that (i) facilitate water transfer and absorption, (ii) sustain plant growth, (iii) resist physical degradation of soil, (iv) produce a safe food resources, (v) cost-effective agricultural management. Possible soil quality indicators are identified at several levels within the framework for each of these functions. Each indicator is assigned a priority or weight that reflects its relative importance using a multi-objective approach based on principles of systems to be considered. To do this, individual scoring system is differentiated by the several levels from low to very high category or point scoring ranging from 0 to 10, And then weights are multiplied and products are summed to provide an overall soil quality rating based on several physical and chemical indicators. Tlne framework and procedure in developing the soil quality assessment are determined by using information collected from an alternative and conventional farm practices in the regions. The use of an expanded framework for assessing effects of other processes, management practices, or policy issues on soil quality is also considered. To develop one possible form for a soil quality index, we should permit coupling the soil characteristics with assessment system based on soil properties and incoming and resident chemicals. The purpose of this paper is to discuss approaches to defining and assessing soil quality and to suggest the factors to be considered.

• Journal of Korea Water Resources Association
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• v.40 no.5
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• pp.419-430
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• 2007

Integrated modelling of surface water and groundwater has become important to satisfy the growing demands for sustainable water resources and improved water quality. In this study, the integrated model of the semi-distributed watershed model, SWA T and the fully-distributed groundwater flow model, MODFLOW is applied to Musirn river basin for the purpose of investigating its applicability to reproduce watershed-scale hydrological processes. This objective is accomplished by first demonstrating good agreement between the simulated discharge hydrographs with the measured hydrographs for the period of 2001 -2004 while simultaneously calibrating the calculated groundwater level distribution to observation wells. Next, the integrated model is used to evaluate the effect of different temporal precipitation averages on hydrodynamic processes of streamflow, percolation, recharge and groundwater discharge. Moreover, comprehensive simulations are performed to present the relationships between monthly precipitation and each hydrological component, and to analyze the temporal-spatial variability of recharge. The results show that the components are highly interrelated, and that the heterogeneity of watershed characteristics such as subbasin slope, land use, soil type causes a significant spatial variation of recharge. Overall it is concluded that the model is capable of reproducing the temporally and spatially varied surface and subsurface hydrological processes at the watershed scale.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.228-228
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• 2018

강변여과는 지하수 인공함양 방식 중 유도함양(induced recharge) 또는 간접함양 방식에 속한다. 이는 하천 및 강변 부근에 집수시설을 설치한 후, 미고결층 대수층(unconsolidated aquifer)의 자연 오염 저감능을 이용하여 지표수를 간접 취수하는 방식으로 수질이 불량한 지표수가 대수층을 관류하면서 희석, 화학적 이온 교환 및 반응, 흡착, 생물막(biofilm; 미생물에 의한 자연저감), 여과 등을 통하여 수질이 개선된다. 강변여과수내의 용존 농도가 높은 철과 망간은 수처리 비용증가, 용수관정 및 시설물의 수명단축을 초래한다. 따라서 강변여과 지역의 미고결 대수층에서 효과적인 철과 망간 동시 제거(vyredox)를 위해 에어서징(air surging)과 블록 서징(block surging)을 실시하기 위해서 실내 물탱크 모델(water tank model)에서 에어서징에 따른 공기 순환 우물시스템을 관찰하였으며, 이를 바탕으로 현장시험(Test bed)에 적용하였다. 미고결 대층수층에서의 철 망간은 음용수 기준치(각각 0.3 mg/L)를 초과하고 있으며, 강변여과 취수 개발 및 이용을 제한하는 요인이 되고 있다. 본 연구에서 사용된 에어서징과 블록서지 기술은 자갈층 및 미고결 대수층에 충진된 슬라임 및 폐색(clogging)을 제거함과 동시에 관정 주변의 대수층의 투수성 개선과 산화환경으로 치환되며, 대수층에 잔존하는 철/망간의 산화물들을 관정내로 빼낼 수 있는 방법이다. 따라서 서징에 따른 폐색 제거효율을 검토한 결과에서 철 망간 이온농도 저감효과와 관정 주변의 수리전도도(hydraulic conductivity) 및 저류계수(coefficient of storage)가 증가한 것으로 나타났다. 이와 같이 강변여과에 의한 폐색은 미고결층내 공기주입 및 블록서지를 통하여 철/망간 이온농도 저감 및 수리특성 개선 효과에 유용한 것으로 평가된다.

• Journal of Environmental Impact Assessment
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• v.26 no.5
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• pp.344-353
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• 2017

Cambodia is a typical country that a very famous tourist destination in South Asian regions, but water has some serious problems. As a public hygiene point of view, water problems in Cambodia can be roughly classified into two categories. A numbers of the report revealed that thermotolerant coliform(TTC) bacteria and arsenic(As) pollution representative species as a representative pollutant for surface water and ground water problems, respectively. In recent years, home water purifier systems for various filter systems including BSF(Bio-Sand Filter), MF and RO have been spread and adopted in rural areas. However, BSF and composite membrane processes are recognized as an undesirable and representative method due to unreliable efficiency, high cost and maintenance issues. In order to develop a small-scale ceramic filter as a home water purifier, the applicability of two types of gravity ceramic filter using clay and red soil in the part of the Northwest was made and compared in this research.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.409-419
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• 2023

Acid mine drainage(AMD) treatment is classified as both passive and active treatment. During the treatment, about 5,000 tons of neutralization sludge is generated as a by-product per year in Korea. This study was conducted to evaluate the characteristics of sludge generated from physico·chemical treatment processes as an active treatment from 5 different sources (D, H, S, T, Y) and the possibility of the sludges being recycled. The sludges have a pH range of 5.86 ~ pH 7.89, and a water content range of 51% ~ 82%. Most of particle sizes were less than 25 ㎛. In analysis of inorganic elements, the concentration of Al, Fe, and Mn were between 1,189 mg/kg ~ 129,344 mg/kg, 106,132 mg/kg ~ 338,011 mg/kg, and 3,472 mg/kg ~ 11,743 mg/kg, respectively. The concentration of As and Zn in sludge-T, Cd in sludge-D, Ni in sludge-H, Zn in sludge-S, and Cd in sludge-Y exceeded the soil contamination standards of Korea. The results from 2 separate kinds of leaching test, the Korea Standard Leaching Test(KSLT) and Toxicity Characteristic Leaching Procedure(TCLP), showed that all the sludges met the Korea groundwater standards. From the XRD and SEM-EDS analysis, the peaks of calcite and quartz were found in the sludges. The sludge also had a high proportion of Fe and O, and the majority of the composition was amorphous iron hydroxide.

• Economic and Environmental Geology
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• v.38 no.1
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• pp.91-99
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• 2005

Acid Rock Drainage(ARD) is the product formed by the atmospheric(i.e. by water, oxygen and carbon dioxide) oxidation of the relatively common iron-sulphur mineral pyrite($FeS_2$). ARD causes the acidification and heavy metal contamination of water and soil and the reduction of slope stability. In this paper the generation characteristics and the prediction of ARD of various cut slopes were studied. An attempt to classify the rocks into several groups according to their acid generation potentials was made. Acid Base Accounting(ABA) tests, commonly used as a screening tool in ARD predictions, were performed. Fourteen rock samples were classified into PAF(potentially acid forming) group and four rock samples into NAF(non-acid forming) group. The chemical analysis of water samples strongly suggested that ARD with high content of heavy metals and low pH could pollute the ground water and/or stream water.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1346-1350
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• 2009

SWAT 모형에서는 중간유출, 침루, 토양 증발, 식물에 의한 증산 등의 수문과정을 모사하기 위해서 토양 수대를 토양의 물리적 특성에 따라 몇 개의 층으로 구분하고, 각 층별로 순차적으로 각 성분량을 계산한다. 이 때 지표유출로 인한 영양물질 이송이 기작되는 영역을 설정하기 위해서 사용자가 입력한 첫 번째 토양층을 강제적으로 둘로 구분하여 상부 10mm의 새로운 토양층이 자동 생성되도록 알고리즘화되어 있다. 그러나, 동일한 토양 특성을 가진 층을 임의적으로 둘로 구분하는 것은 토양 물리적 관점에서 보면 적절하지 않으며, 또한 생성된 매우 얇은 상부 10 mm 토양층으로 인해서 포장용수량을 초과하는 과잉수가 커서 경사가 급한 유역이나 토양층의 투수성이 매우 큰 지역에 모형을 적용할 경우에는 중간유출량이 비현실적으로 크게 계산되는 문제를 수반한다. 따라서 본 연구에서는 중간유출이 크게 계산되는 문제점을 해결하고 토양층내의 수분 거동을 보다 현실적으로 모사하기 위해서 합체-분리 (combining-partitioning) 방식의 토양층 구조화 기법을 고안하고 SWAT의 지표하 유출 계산 모듈에 새롭게 추가하였다. 모형 개선이 수문 및 수질 성분 모의에 미치는 영향을 평가하기 위해서 충주댐 상류유역을 대상으로 모델링을 수행하고 상대비교를 한 결과, 토양수분, 중간 및 지하수유출, 인 순환에 미치는 영향이 가장 큰 것으로 분석되었다.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.463-471
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• 2006

Electrical resistivity surveys were conducted at areas of abandoned landfills in Cheonan and Wonju. Geology and extent of leachate migration around the landfills were evaluated with collected resistivity data by 2-D and 3-D resistivity inverse modeling. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to examine possible pollution at the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system, which has not been in operation. To evaluate leachate leakage into the paddy fields, a total of 4 survey lines were used. According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and the leachate would reach the downgradient paddy fields. Low resistivity area was observed in the old reservoir area and it appeared to be derived from convergence of groundwater flows from the surrounding valley and the moist wet land. In addition, groundwater flow into the paddy fields occurs beneath the old reservoir embankment at depths of $7{\sim}8m$. This paper reports details of the resistivity surveys for the uncontrolled landfills.

• Journal of the Korean GEO-environmental Society
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• v.13 no.1
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• pp.5-13
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• 2012

For the last decade the amount of waste has rapidly been increased in South Korea and many waste landfills have been built according to government guidelines specifying required systems such as landfill liner, leachate collecting facilities, final cover system, etc. This effort has led the recently constructed landfills to be under well managed sanitary condition. In a meanwhile closed waste-landfill sites in the past before the adoption of the government guidelines exits under unsanitary condition. In these cases untreated leachate flew out to the surroundings due to the absence of liner and leachate collecting facilities and caused groundwater and soils to be contaminated. Waste generated odor and gas also brought civil complaints. Because environmental influences bring serious problems nearby sites, it is required to have unsanitary waste-landfills to be appropriately treated and managed. A study to evaluate environmental influence and contamination level of surroundings nearby and on the unsanitary landfills is necessary before the establishment of "Management guide of closed landfill site." This paper presents an environmental evaluation for the closed site, Doil-dong landfill, according to "Closed landfill management regulation" by Ministry of Environment. "D" landfill, located in Pyeongtaek city, has possobility to contaminate surrounding surfacewater and groundwater by leakage of leachate. The in-situ stabilization carried out to build the DMW(deep soil mixing cutoff wall) wall and drainage systems.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.31-39
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• 2002

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water column can accumulate in sediments at much higher levels. The purpose of this study was to make optimal treatment and disposal plan o( sediment for water quality improvement in small-scale resevoir based on an evaluation of degree of contamination. The degree of contamination were investigated for 23 samples of 9 site at different depth of sediment in small-scale J river. Results for analysis of contaminated sediments were observed that copper concentration of 4 samples were higher than the regulation of hazardous waste (3 mg/L) and that of all samples were exceeded soil pollution warning levels for agricultural areas. Lead and mercury concentration of all samples were detected below both regulations. Necessary of sediment dredge was evaluated for organic matter and nutrient through standard levels of Paldang lake and the lower Han river in Korea and Tokyo bay and Yokohama bay in Japan. The degree of contamination for organic matter and nutrient was not serious. Compared standard levels of Japan, America, and Canada for heavy metal, contaminated sediment was concluded as lowest effect level or limit of tolerance level because standard levels of America and Canada was established worst effect of benthic organisms. The optimal treatment method of sediment contained heavy metal was cement-based solidification/stabilization to prevent heavy metal leaching.