• 한국토양비료학회지
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• 제30권1호
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• pp.67-71
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• 1997

농경지의 정밀토양조사(精密土壤調査) 결과를 이용하여 토양유형(土壤類型), 지형(地形) 및 층위별(層位別)로 토양의 물리, 화학적 특성을 분석 검토한 결과는 다음과 같다. 1. 점토함량(粘土含量)을 유형별로 보면 A층에는 사질밭과 보통밭에서 낮았고 중점(重粘)밭에서 가장 높았으며 B층에서는 화산회밭이 높았다. 토층간에는 화산회밭을 제외하고는 B층이 A층보다 낮았다. 2. 유기물함량(有機物含量)은 다른 유형의 밭에 비하여 화산회밭과 고원(高原)밭에서 현저히 높았다. 3. 양이온치환용량은 사질밭, 보통밭과 미숙(未熟)밭에서 낮았으며 고원밭의 A층도 $13.2cmol^+/kg$으로 높은 편이었고 화산회밭은 가장 높았다. 4. 보통(普通)밭 B층의 물리 화학적 특성간에는 높은 상관관계가 인정되었으며 양이온치환용량은 유효수분(有效水分), 점토, 미사 및 유기물함량과 정(正)의 상관(相關)관계를 보였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권spc호
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• pp.19-33
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• 2022

When subsurface is polluted, contaminants tend to migrate through groundwater flow path. The groundwater flow path is highly dependent upon underground geological structures in the contaminated area. Geophysical survey is an useful tool to identify subsurface geological structure. In addition, geophysical logging in a borehole precisely provides detailed information about geological characteristics in vicinity of the borehole, including fractures, lithology, and groundwater level. In this work, surface seismic refraction and electrical resistivity surveys were conducted in a test site located in Namyangju city, South Korea, along with well logging tests in five boreholes installed in the site. Geophysical data and well logging data were collected and processed to construct an 3D geological map in the site.

• 한국토양비료학회지
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• 제17권4호
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• pp.330-336
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• 1984

우리나라 토양(土壤)의 대표적(代表的)인 물리화학적(物理化學的) 성질(性質)을 구명(究明)하여 토지생산력(土地生産力) 향상(向上)을 위(爲)한 토양(土壤) 개량(改良)에 필요(必要)한 자료(資料)를 제공(提供)하고자 정밀(精密) 토양조사(土壤調査) 결과(結果) 밝혀진 제주도(濟州道) 토양(土壤)을 제외(除外)한 315개(個) 토양통(土壤統)에 대(對)한 토성(土性), 수분특성(水分特性), 유기물함량등(有機物含量等) 14개(個) 물리화학성(物理化學性)을 수집(蒐集)하여 토지이용(土地利用), 배수등급(排水等級), 토양유형별(土壤類型別)로 단순(單純) 평균치(平均値)와 분포면적(分布面積)을 고려(考慮)한 가중(加重) 평균치(平均値)를 전산처리(電算處理)한 결과(結果)는 다음과 같다. 1. 우리나라 전체(全體) 토양통(土壤統)의 단순(單純) 평균치(平均値)는 점토(粘土) 20.0%, 유기물(有機物) 2.03%, 양(陽)이온 치환용량(置換容量) 10.3me/100g이었으며 분포면적(分布面積) 가중평균치(加重平均値)는 점토(粘土) 18.0%, 유기물(有機物) 1.85%, 양(陽)이온 치환용량(置換容量) 8.6me/100g 으로 밝혀졌다. 2. 토지이용(土地利用別)로 점토함량(粘土含量)을 보면 논이 19.7%에 비(比)하여 밭과 임지(林地)는 각각(各各) 17.9%, 16.7%로 낮은 편이고 유기물함량(有機物含量)은 논이 2.0%로서 밭과 임지(林地)의 1.8%보다 높았으며 양(陽)이온 치환용량(置換容量)도 논이 9.1me/100g으로 가장 높고 다음으로 임지(林地)는 8.6me/100g, 밭은 8.1me/100g의 순(順)이다. 3. 배수등급별(排水等級別) 가중평균치(加重平均値)를 보면 배수(排水) 약간(若干) 양호(良好)한 경우 점토함량(粘土含量) 18.9%, 유기물(有機物) 1.7%, 양(陽)이온 치환용량(置換容量) 8.4me/100g이고 약간(若干) 불량(不良)인 경우는 점토함량(粘土含量) 21.3%, 유기물(有機物) 2.2%, 양(陽)이온 치환용량(置換容量) 9.5me/100g 이었고 불량(不良)인 경우는 점토함량(粘土含量) 15.1%, 유기물(有機物) 1.8%로서 양(陽)이온 치환용량(置換容量)만이 9.9me/100g으로 제일 높았다. 4. 논, 밭토양(土壤)에 대(對)한 유형별(類型別) 점토함량(粘土含量), pH, 유기물(有機物), 양(陽)이온 치환용량(置換容量), 염기포화도등(鹽基飽和度等)이 밝혀졌다.

• 한국토양비료학회지
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• 제30권1호
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• pp.62-66
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• 1997

논토양에 대한 전산화(電算化)된 정밀토양조사자료(精密土壤調査資料)를 이용(利用)하여 논토양(土壤) 유형별(類型別) 13개(個) 물리화학적인 특성의 평균치(平均値)를 구하고 토양개량(土壤改良)에 대한 기초자료(基礎資料)를 제공하고자 전산자료를 분석, 검토한 결과는 다음과 같다. 1. 논토양 B층위(層位)에서의 점토함량은 보통답(普通畓)이 28.3%, 사질답(砂質畓)이 11.8%, 미숙답(未熟畓)이 26.8%이었으며 토양 pH는 습답(濕畓), 특이산성답(特異酸性畓)을 제외하고는 B층(層)이 A층(層)보다 높았다. 2. 보통답중(普通畓中)에서 하천변(河川邊)논 A, B층의 점토함량은 각각 16.8%, 23.1%로 가장 낮았고 유기물함량은 42g/kg, 18g/kg로 가장 많았으며 유효인산함량도 가장 많았다. 3. 논토양 유형별(類型別) B층(層)의 유기물함량수준별 분포비율(分布比率)은 사질답, 미숙답은 10g/kg 이하가 가장 많고 특이산성답을 제외한 각 답유형에서는 10~20g/kg 범위가 가장 많았다. 4. 보통답(普通畓) B층위(層位)에서 물리화학성 상호간의 상관계수(相關係數)는 전부 1~5% 수준내에서 유의성(有意性)이 높았다.

• 한국농공학회논문집
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• 제59권2호
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• pp.13-18
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• 2017

Farmers seek for high profitability by increasing the best use of land, and the selection of crops is the first and basic way to achieve their goals. When farmers select crops, the climate, price and productivity of crops are usually considered at the first stage. However, a crucial factor is to understand general characteristics of soils where the crops were grown, but many farmers are lacking in detailed knowledge about soils. The purpose of this study is to search and analyses factors based upon related soil and others in decision-making for the selection of crops. In result, the cultivated rate of the top 5 corps in the suitable areas for cultivation (SAC) is only 53 % which shows most farmers are plants their crops in unsuitable sites. To examine factors influencing on the selection of crops except for soils, surveys about their farm characteristic and Korea Soil Information System (KSIS) were conducted. The result of survey shows 20 % of farmers know KSIS. To increase that rate, there were many changes on soil's characteristic, and at the same time, climate conditions should be updated. It can be expected to increase the rate of farmers' utilization of KSIS.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권2_spc호
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• pp.1-15
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• 2020

Monitoring and assessing terminal electron accepting processes (TEAPs) are one of the most important steps to remediate contaminated sites via various in-situ techniques. TEAPs are a part of the microbial respiration reactions. Microorganisms gain energy from these reactions and reduces pollutants. Monitoring TEAPs enables us to predict degradability of contaminants and degradation rates. In many countries, TEAPs have been used for characterization of field sites and management of groundwater wells. For instance, US Environmental Protection Agency (EPA) provided strategies for groundwater quality and well management by applying TEAPs monitoring. Denmark has also constructed TEAPs map of local unit area to develop effective groundwater managing system, particularly to predict and assess nitrogen contamination. In case of Korea, although detailed soil survey and groundwater contamination assessment have been employed, site investigation guidelines using TEAPs have not been established yet. To better define TEAPs in subsurface environments, multiple indicators including ion concentrations, isotope compositions and contaminant degradation byproducts must be assessed. Furthermore, dissolved hydrogen concentrations are regarded as significant evidence of TEAPs occurring in subsurface environment. This review study introduces optimal sampling techniques of groundwater and dissolved hydrogen, and further discuss how to assess TEAPs in contaminated subsurface environments according to several contamination scenarios.

• Advances in concrete construction
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• 제16권2호
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• pp.79-89
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• 2023

The occurrence of unexpected horizontal offset in the instrument or target will result in accumulated horizontal deviation in segment alignment with traditional short-line match method. A geometry control method, the four-point method, is developed for precast segmental bridges to avoid the influences of unexpected horizontal offset. The concept of the four-point method is elucidated. Furthermore, the detailed instruments and instructions are introduced. Finally, the four-point method is validated through a practical engineering application. According to the survey data, after short-line match precast construction, the vertical deviations on both sides vary between -5 mm and 5 mm in almost all segments, and the horizontal deviations vary between -4 mm and 4 mm in all segments. Without on-site adjustment, the maximum vertical and horizontal closure gaps are 12.3 and 26.1 mm, respectively. The four-point method is suggested to alleviate the issues associated with relatively poor soil conditions in casting yard.

• 지질공학
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• 제31권3호
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• pp.269-281
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• 2021

Land creeping is the imperceptibly slow, steady, downward movement o f slope-forming soil or rock. Because creep-related failures occur frequently on a large scale without notice, they can be hazardous to both property and human life. Korea Forest Service has operated the prevention and response system from land creeping which has been on the rise since 2018. We categorized and proposed three survey steps (e.g., preliminary, regional, detailed) for investigation of creeping susceptibility site with a focus on geophysical mapping of a selected test site, Yongheung-dong, Pohang, Korea. The combination of geophysical (dipole-dipole electrical resistivity tomography and reciprocal seismic refraction technique, well-logging), geotechnical studies (standard penetrating test, laboratory tests), field mapping (tension cracks, uplift, fault), and comprehensive interpretation of their results provided the reliable information of the subsurface structures including the failure surface. To further investigate the subsurface structure including the sliding zone, we performed high-resolution geophysical mapping in addition to the regional survey. High-resolution seismic velocity structures are employed for stability analysis because they provided more simplified layers of weathering rock, soft rock, and hard rock. Curved slip plane of the land creeping is effectively delineated with a shape of downslope sliding and upward pushing at the apex of high resistive bedrock in high-resolution electrical resistivity model with clay-mineral contents taken into account. Proposed survey steps and comprehensive interpretation schemes of the results from geological, geophysical, and geotechnical data should be effective for data sets collected in a similar environment to land-creeping susceptibility area.

• 환경정책연구
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• 제3권2호
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• pp.31-57
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• 2004

Attempts were made to compare and analyze the policies of the United States, the United Kingdom, the Netherlands, Germany and Denmark concerning Korea's major problems associated with legal liability of the contaminated sites. These countries were chosen from a feasible preliminary analysis of 18 countries of the EU and the U. S. The major problems were revealed based on the analysis of Korean legacy and legislation, which are summarized as follows i) lack of clear detailed technical and legal guidance to determine the responsible party or parties of contaminated sites, ii) no distinction between the strict and non strict legal liability of innocent land owners, iii) no clearly set limit on retroactive legal liability. Comparison of the policies of countries chosen suggested improvements regarding these major problems as follows: i) activating national and international research on soil contamination prevention policy, ii) arranging distinct legal regulation between strict and non strict liability criteria, iii) establishing the limits on innocent and non strict liability, iv) establishing methodology and process of legal liability distribution and compensation, and v) establishing a legal process to redeem any benefit derived from remediation of contaminated sites with the public budget. Our policy suggestions above are not yet conclusive due to a lack of policy implementation simulation. Additional research is needed on aspects of social, economic and long term effects of the proposed policy directions. Nevertheless, application of the policy suggestions of this research would increase the efficacy of Korean policy regarding the survey and remediation of the potentially contaminated sites.

• 농촌계획
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• 제30권1호
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• pp.57-66
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• 2024

This study aimed to develop a precise vegetation cover classification model for small streams using the combination of drone remote sensing and support vector machine (SVM) techniques. The chosen study area was the Idong stream, nestled within Geosan-gun, Chunbuk, South Korea. The initial stage involved image acquisition through a fixed-wing drone named ebee. This drone carried two sensors: the S.O.D.A visible camera for capturing detailed visuals and the Sequoia+ multispectral sensor for gathering rich spectral data. The survey meticulously captured the stream's features on August 18, 2023. Leveraging the multispectral images, a range of vegetation indices were calculated. These included the widely used normalized difference vegetation index (NDVI), the soil-adjusted vegetation index (SAVI) that factors in soil background, and the normalized difference water index (NDWI) for identifying water bodies. The third stage saw the development of an SVM model based on the calculated vegetation indices. The RBF kernel was chosen as the SVM algorithm, and optimal values for the cost (C) and gamma hyperparameters were determined. The results are as follows: (a) High-Resolution Imaging: The drone-based image acquisition delivered results, providing high-resolution images (1 cm/pixel) of the Idong stream. These detailed visuals effectively captured the stream's morphology, including its width, variations in the streambed, and the intricate vegetation cover patterns adorning the stream banks and bed. (b) Vegetation Insights through Indices: The calculated vegetation indices revealed distinct spatial patterns in vegetation cover and moisture content. NDVI emerged as the strongest indicator of vegetation cover, while SAVI and NDWI provided insights into moisture variations. (c) Accurate Classification with SVM: The SVM model, fueled by the combination of NDVI, SAVI, and NDWI, achieved an outstanding accuracy of 0.903, which was calculated based on the confusion matrix. This performance translated to precise classification of vegetation, soil, and water within the stream area. The study's findings demonstrate the effectiveness of drone remote sensing and SVM techniques in developing accurate vegetation cover classification models for small streams. These models hold immense potential for various applications, including stream monitoring, informed management practices, and effective stream restoration efforts. By incorporating images and additional details about the specific drone and sensors technology, we can gain a deeper understanding of small streams and develop effective strategies for stream protection and management.