• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.413-424
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• 2020

Environmental policies and industry practices have recently seen a gradual paradigm shift from reactive management to proactive prevention of environmental impacts. Accordingly, preventive conservation policies are carried out to address the increasing value of protecting soils and soil functions as resources are limited. To propose a direction for future soil erosion research, we analyzed domestic and international research trends of soil erosion, based on journal papers retrieved from the Web of Science databases over the last decade, using VOSviewer for keyword co-occurrence analysis. The results showed that the number of publications on soil erosion per land area in Korea ranked high worldwide. In particular, studies on the soil erosion control were found to account for a more significant proportion than other countries. The active ongoing studies on soil erosion in Korea indicate that the country has recognized the severity of soil erosion resulting from climate, topography, and land use. However, the number of keywords found in the studies on the soil erosion control in Korea was relatively smaller than those found at the international level, indicating the need to diversify and expand the study subjects. In particular, studies on the soil erosion process and the related physical and chemical soil properties are necessary to find the fundamental solutions to soil erosion problems.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.7-13
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• 1985

The cropping management factor, C, in the Universal Soil Loss Equation (USLE) has been measured on a newly reclaimed Yesan sandy loam of 20% slope under various cropping system. Soil losses measured from lysimeter were 12.9, 5.4, 3.1, and 1.2 ton/10a for clean tilled, corn, barley-soybean, and grass, respectively. The values of C to be utilized in Soil-Loss Equation was obtained as fallows; corn 0.47, upland rice 0.34, barley-soybean 0.18, barley-sweet potato 0.10, grass 0.08, barley-corn 0.34, wheat-soybean 0.25, barley-corn (Soybean) 0.42, barley-corn (sweet potato) 0.37, wheat-sesame 0.20, barley-red pepper 0.18, red pepper 0.32, sesame 0.28, potato-soybean 0.26, respectively. According to the comparisons between the actual soil loss measured by lysimeter and the soil loss predicted by the USLE, the smallest difference of both method came from barley-soybean while the largest came from corn.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.87-92
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• 2002

Soil erosion is detrimental to sustain soil productivity in north Korea, since agriculture of this country depends largely upon the slope land in mountainous area. Taking any measure for protection from erosion should be based on prediction of soil loss. Estimation of rainfall factor, R, in north Korea for the Universal Soil Loss Equation was attempted. The monthly precipitation data of the twenty six locations provided by the Korean Meteorological Adminstration were used. From the relationship between II_30 and the July-August precipitation concentration percents, the regional adjustment factor was obtained. The rainfall factor was calculated with the monthly precipitation data and the regional adjustment factor. The annual precipitation in north Korea ranged from 606 to 1,520mm, and the July-August precipitation concentration percents were 34.4 to 53.8. The regional adjustment factor ranged from 0.53 to 1.33 showing lower value in the highland and east coastal region than in the mid mountainous inland and west region. The R-factor value estimated from the monthly precipitation and the regional adjustment factor ranged from 107 to 483, which was lower than average value in south Korea.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.1-24
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• 2000

21세기는 생명, 환경, 정보를 주제로 새 시대를 맞이하고 있다. 20세기 절대빈곤에서 벗어나기 위한 성장제일주의의 경제개발정책은 짧은 시간에 성공적으로 달성되어 높은 문화수준과 산업사회를 이룰 수 있었다. 한편, 국민생활향상과 산업발전에 결정적 역할을 해왔던 수자원개발은 동강에서, 시화호에서, 지리산, 인천 앞바다에서 개발 부작용으로 생태와 환경이 심한 몸살을 앓기 시작하고 있다. WTO에 의한 시장개방으로 생산구조가 붕괴되고 농촌지역이 공동화될 것을 걱정하고 있다. 누군가는 농촌에서 농사를 짓고 살아야만 국가의 산업구조가 유지되고 아름다운 국토의 자연환경을 보전할 수 있다. 농촌은 식량생산을 위한 공간과 인간생활을 위한 공간 등 두 가지 기능을 가진 공간이다. 쾌적한 농촌을 이룩하려면 농업생산성을 향상시켜 농업소득을 높이고, 농공단지의 활성화와 농촌관광과 휴양시설에 의한 농외소득을 강화해야 한다. 또한, 농업은 식량의 안정적 공급은 물론 홍수 및 토양침식 억제, 수자원함양, 수질정화, 대기정화, 생물 다양성 등 환경보전적 기능이 WTO에 대응하여 쌀시장을 지킬 수 있는 논리로 새롭게 평가받고 있다. George Brokeway (경제인의 종말, 1991)의 “ 이윤극대화라는 경제원칙이 인간의 자연파괴와 기상이변 앞에 모순을 드러내고 있어 경제학의 인간화를 요구하고 있다.”는 지적에 비교우위론자들은 다시 한번 귀기울여주기 바란다.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.61-72
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• 2004

The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.21-29
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• 1999

This study was carried out to clarify the syntaxonomy of the pine forest in Youngdong region by the phytosociological methods. As a result of the investigation of 62 quadrats, Pinus densiflora forest was classified into four subassociations: Typical subassociation, Quercus mongolica subassociation, Rhododendron mucronulatum subassociation, Rhus chinensis subassociation. Many differences in ecological characteristics such as species composition, stratum structure, vegetation coverage and of diameter at breast height(DBH) of class distribution were found among the communities. Soil properties of the pine forest on the study area was relatively poor compared with other pine forests, especially, soil pH was strongly acidic with 4.87. Soil conditions among the subassociations appeared different. Future succession of pine forest by the similarity index of communities was proposed. Estimated degree of green naturality for Typical subassociation and Q. mongolica subassociation correspond to 7th grade, and R. mucronulatum subassociation, 8-1st grade, and R. chinensis subassociation, 8-2nd grade.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.19-26
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• 2012

The purpose of this study was to provide basic data for the cultivation of Allium victorialis var. platyphyllum in the area covered with forest vegetation. The populations of A. victorialis var. platyphyllum in Ulleungdo were naturally growing in the communities of Fagus japonica var. multinervis, Acer okamotoanum, Pinus parviflora, Tsuga sieboldii, Pinus densiflora, Pinus thunbergii, Tilia amurensis, and Alnus maximowiczii. On average, the study area of A. victorialis var. platyphyllum population was located in the places of 563 m above sea level, and in the slope area of $27.8^{\circ}$. Soil texture of its inhabitation site mainly consisted of sandy soil, sandy loam, loamy sand, and loam. The depth of the organic layer was 6 cm on average, soil pH 5.4, available phosphate content 18.5 ppm, and cation exchange capacity $18.6cmol_c/kg$. The correlation between the site factors and soil factors by CCA analysis showed that the community of beech tree indicated positive correlation with carbon, nitrogen, sand content, and cation exchange capacity.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.450-450
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• 2021

기후변화 보고서에 따르면 집중 호우의 강도 및 빈도 증가가 향후 몇 년동안 지속될 것이라 제시하였다. 이러한 집중호우가 빈번히 발생하게 된다면 강우 침식성이 증가하여 표토 침식에 더 취약하게 발생된다. Universal Soil Loss Equation (USLE) 입력 매개 변수 중 하나인 강우침식능인자는 토양 유실을 예측할때 강우 강도의 미치는 영향을 제시하는 인자이다. 선행 연구에서 USLE 방법을 사용하여 강우침식능인자를 산정하였지만, 60분 단위 강우자료를 이용하였기 때문에 정확한 30분 최대 강우강도 산정을 고려하지 못하는 한계점이 있다. 본 연구의 목적은 강우침식능인자를 이전의 진행된 방법보다 더 빠르고 정확하게 예측하는 머신러닝 모델을 개발하며, 총 월별 강우량, 최대 일 강우량 및 최대 시간별 강우량 데이터만 있어도 산정이 가능하도록 하였다. 이를 위해 본 연구에서는 강우침식능인자의 산정 값의 정확도를 높이기 위해 1분 간격 강우 데이터를 사용하며, 최근 강우 패턴을 반영하기 위해서 2013-2019년 자료로 이용했다. 우선, 월별 특성을 파악하기 위해 USLE 계산 방법을 사용하여 월별 강우침식능인자를 산정하였고, 국내 50개 지점을 대상으로 계산된 월별 강우침식능인자를 실측 값으로 정하여, 머신러닝 모델을 통하여 강우침식능인자 예측하도록 학습시켜 분석하였다. 이 연구에 사용된 머신러닝 모델들은 Decision Tree, Random Forest, K-Nearest Neighbors, Gradient Boosting, eXtreme Gradient Boost 및 Deep Neural Network을 이용하였다. 또한, 교차 검증을 통해서 모델 중 Deep Neural Network이 강우침식능인자 예측 정확도가 가장 높게 산정하였다. Deep Neural Network은 Nash-Sutcliffe Efficiency (NSE) 와 Coefficient of determination (R²)의 결과값이 0.87로서 모델의 예측성을 입증하였으며, 검증 모델을 테스트 하기 위해 국내 6개 지점을 무작위로 선별하여 강우침식능인자를 분석하였다. 본 연구 결과에서 나온 Deep Neural Network을 이용하면, 훨씬 적은 노력과 시간으로 원하는 지점에서 월별 강우침식능인자를 예측할 수 있으며, 한국 강우 패턴을 효율적으로 분석 할 수 있을 것이라 판단된다. 이를 통해 향후 토양 침식 위험을 지표화하는 것뿐만 아니라 토양 보전 계획을 수립할 수 있으며, 위험 지역을 우선적으로 선별하고 제시하는데 유용하게 사용 될 것이라 사료된다.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.31-38
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• 1999

Rainfall factor. R, and soil factor, K were estimated to use the Revised Universal Soil Loss Equation (RUSLE) to predict the amount of soil erosion from a land on slope in Kangwon-do, Korea. The average of R factor was 405 with a range from 251 to 601. The R factor differed among regions. The R factor at Taegwalryung, in the highland region, was 409 and those at Inje and Hongchon, in the mid mountainous regions, ranged from 310 to 493. The R factors at Wonju and Chuncheon, in the plain regions, ranged from 505 to 601. The R factors at Sokcho, Kangnung and Samchok, in the east coastal region, which ranged from 251 to 368, were lowee than those in the western part of the Taebaeg Mountains. The R factor during the winter including the effect of winter freezing and thawing was 12 to 30% of the annual average value in the east coastal and highland regions, while that in the western part of Taebaeg Mountains was lower than 7%. The average of K factor in the surface soil was 0.21 with a range from 0.06 to 0.42. The K factors of Odae and Weoljeong serieses were the lowest, while that of Imog was the highest. The average of K factor in the subsoil was 0.28 with a range from 0.07 to 0.45. The K factor of the subsoil was 1.3 times higher than that of top soil. The average of K factor in he soil including the effect of the gravel covering and percolation was 0.18 with a range from 0.03 to 0.33. In contrast. the K factor excluding the effect of the gravel covering was lower than this. The average of K factor in the frozen subsoil was 0.33, which was 1.6 times higher than that of the non frozen subsoil.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.134-141
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• 2005

Cultivation of winter cover crops and its soil utilization for summer main crops in slope upland is very important at the respects of diminution of soil erosion and non-point pollution source. The effects of cover crop, hairy vetch as no-tillage or conventional tillage on prevention of soil erosion and reduction of chemical nitrogen fertilization were investigated in the slope upland with whiter clover living mulch (partial tillage) in Suwon for three years and with rye (conventional tillage) in Hongcheon for two years, respectively. In Suwon, amounts of soil lost by rainfall runoff decreased as much as 90% by hairy vetch-no tillage (HV-NT), white clover-partial tillage (WF-PT) together with the decrease of rainfall runoff compared to winter fallow with conventional tillage (WF-CT). In addition, amounts of weed also decreased as much as 80-90% by HV-NT and WF-PT. Corn yield decreased much at the plot of WF-PT mainly due to competition for soil water and nutrients between clover and corn at the early corn growth stage. On the contrary, corn yield increased by HV-NT compared to WF-CT regardless of weed control. In Hongcheon, amounts of soil eroded during winter season before corn seeding were reduced as much as 95% by cultivation of hairy vetch and rye compared to winter fallow. Amount of soil eroded during waxy corn growing season was reduced as much as 98% by HV-NT compared to WF-CT. Also, soil incorporation of hairy vetch and rye as green manure with conventional tillage at corn seeding time could reduce soil erosion as much as 70% compared to no soil cover with conventional tillage. Ear yields of waxy corn were increased 10% higher at hairy vetch green manure (HV-CT) without nitrogen fertilizer, 20% higher at HV-NT with standard nitrogen fertilizer, respectively than WF-CT. But ear yields of waxy corn were decreased by rye green manure (R-CT) and HV-NT at the condition of no nitrogen fertilizer. It was concluded that hairy vetch was better as winter cover crop to reduce both soil erosion and chemical nitrogen fertilizer simultaneously in slope upland than other cover crops.