• 한국환경농학회지
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• 제26권4호
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• pp.279-285
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• 2007

Soil physical properties in organic farming apple orchard were evaluated in relation to conventional farming to better understand the effects of organic farming system on soil quality. Two adjacent apple orchards, matched by soil type, were chosen to ensure the same pedological conditions except management system. Soil samples were collected from middle of two adjacent trees along the tree line at two depths of 5-20 and 20-35 cm in September 2006. Contents of organic matter in organic farming soil were twice as much as those found in soil of conventional farming. The higher level of organic matter in organic farming soil was reflected through a consequent trend in improved soil physical properties. Organic farming produced greater aggregation in >2 mm size and increased aggregate stability. Bulk density was lower by 13% and hence porosity was higher in soils of organic farming as compared with conventional farming. Water holding capacity was significantly greater with organic farming by >17% over conventional farming. The capacity of organic farming to improve soil physical properties can be contributed to the regular application of relatively large amount of organic materials and the sustainable ground-cover managements, mulching with compost and cover crop cultivation.

• 한국토양비료학회지
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• 제34권3호
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• pp.147-152
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• 2001

This study was carried out to investigate the effect of application time and amount of liquid pig manure on growth and yield of rice plant and infiltration water quality. Liquid manure treatment with higher application rate and closer application time to transplanting time showed higher plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and lodging. In liquid manure treatment with higher application rate, number of panicles per hill and number of spikelets per panicle were higher but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample was increased with increasing application amount of liquid manure and closer application time to transplanting of rice plant. With consideration yield of rice and environment such as groundwater quality, the proper application amount were 150% and 100% of recommending N fertilizer level (11kg) at before winter and April or May treatment, respectively.

• 한국산림과학회지
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• 제87권1호
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• pp.62-73
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• 1998

이 연구(硏究)는 계류수(溪流水)에서 수질평가항목(水質評價項目)의 설정시(設定時) 중요한 인자(因子)인 양(陽)이온($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$)과 음(陰)이온($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$)에 미치는 영향요인을 구명(究明)함으로써 계류수질평가기준(溪流水質評價基準)을 정립(定立)하기 위한 기초자료(基礎資料)를 제공(提供)하기 위하여 서울대학교(大學校) 농업생명과학대학(農業生命科學大學) 부속(附屬) 관악수목원내(冠岳樹木園內) 산림소유역(山林小流域)의 3개 조사구(調査區)에서 수행(遂行)하였다. 1996년 7월 1일부터 1997년 8월 31일까지 강수(降水), 수관통과우(樹冠通過雨), 토양수(土壤水) 그리고 계류수(溪流水)의 수질동태(水質動態)를 분석(分析)한 결과(結果), 계류수(溪流水)에 용존(溶存)되어 있는 $Cl^-$이온은 강수(降水)나 수관통과우(樹冠通過雨)보다는 토양수(土壤水)에 용존(溶存)되어 있는 $Cl^-$이온과 유의(有意)한 상관관계(相關關係)를 나타내었으며, 토양수(土壤水)에 용존되어 있는 $NO{_3}^-$이온은 강수(降水)에 용존되어 있는 $NO{_3}^-$이온과 유의(有意)한 상관관계(相關關係)를 나타내었다. 또한 토양(土壤) A층(層)과 B층(層)의 토양수(土壤水)에 용존되어 있는 양(陽)이온($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$)과 음(陰)이온($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$)은 통계적(統計的)으로 유의(有意)한 상관관계(相關關係)를 나타내었다. 강수(降水)에 용존(溶存)되어 있는 $NO{_3}^-$이온과 $SO{_4}^{2-}$이온의 평균농도비(平均濃度比)는 약 0.66으로 강수(降水)에는 $NO{_3}^-$이온보다는 $SO{_4}^{2-}$이온이 더 많이 함유(含有)되어 있었다. 전체 조사구에서 강수(降水), 수관통과우(樹冠通過雨), 토양수(土壤水)의 음(陰)이용량(量)은 계류수(溪流水)에 용존(溶存)하는 음(陰)이온량(量)과 유의(有意)한 상관관계(相關關係)를 나타내었으며, 강수(降水), 수관통과우(樹冠通過雨), 토양수(土壤水), 계류수(溪流水)에 용존(溶存)되어 있는 이온총량(總量)의 평균값의 크기는 토양수(土壤水)(B층(層)>A층(層))>수관통과우(樹冠通過雨)(리기다소나무림 > 벚나무림 > 서어나무림) > 계류수(溪流水) > 강수(降水)의 관계(關係)이었다.

• 한국수자원학회논문집
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• 제42권10호
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• pp.877-889
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• 2009

본 연구에서는 SWAT(Soil and Water Assessment Tool) 모형을 이용하여 미래 기후변화가 충주댐 유역(6,585.1 km$^2$)의 하천수질에 미치는 영향을 분석하고자 하였다. 미래 기상자료는 IPCC에서 제공하는 A2, A1B, B1 배출시나리오를 포함하는 ECHAM5-OM 모형의 결과를 과거 30년(1977-2006, baseline period) 기후자료를 바탕으로 편이보정(bias correction)과 Change Factor Method로 Downscaling 하였다. 6년(1998-2003) 동안의 일별 유출량 및 월별 수질(SS, T-N, T-P) 자료를 이용하여 모형의 보정 및 검증을 실시한 후, Downscaling된 ECHAM5-OM의 A2, A1B, B1 시나리오에 대해 2020s, 2050s, 2080s로 대별되는 미래의 수문학적 거동 변화 및 하천수질 변화를 전망하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.422-425
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• 2003

This study was carried out to apprehend the variation of quality of mine drainage in the abandoned Samtan coal mine. After closure of coal mine, although still pumping, water level in underground was raised to loom and the concentration of some elements such as Fe and Mn was elevated. At present, the worst pollution source in this area is too the acidic leachate drained from uncovered mine waste impoundment. The flow rate of mine drainage from the adit is ave. about 20,000t/d. If water were flooded and deteriorated due to stopping pumping, the impact of the mine drainage on the stream around the abandoned mine would be more severe. Therefore, It is considered that the prediction of water quality of mine drainage from the adit after stopping pumping will be very important with a view to establishing countermeasures.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.316-318
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• 2006

The purpose of this research is to write out vulnerability for western area in Jeju island by using drastic method which is the most frequently utilized among the writing techniques of underground water vulnerability. In case of aquifer, it was divided into two types, gravel layer or not and rated. And soil media was rated two kinds of method. Plan 1 is concerned with only soil class and plan 2 is concerned with soil class and gravels (or rocks), Vadose zone was rated differently according to the ratio of gravel layer. In case of plan 1, the scope of drastic index is from the minimum 77 to the maximum 176, on the other hand, plan 2, the scope of drastic index is from the minimum 79 to the maximum 182. In case of using the water quality data of Nitrate from 1994 to 2004, Pearson correlation coefficient are 0.164(Plan 1) and 0.124(Plan 2) and Spearman correlation coefficient are 0.132(Plan 1) and 0.113.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.172-172
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• 2020

In recent years, soil erosion has come to be regarded as an essential environmental problem in human life. Soil erosion causes various on- and off-site problems such as ecosystem destruction, decreased agricultural productivity, increased riverbed deposition, and deterioration of water quality in streams. To solve these problems caused by soil erosion, it is necessary to quantify where, when, how much soil erosion occurs. Empirical erosion models such as the Universal Soil Loss Equation (USLE) family models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well by utilizing big data related to climate, geography, geology, land use, etc. within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models remain powerful tools to distinguish erosion-prone areas at the macro scale but physics-based models are necessary to better analyze soil erosion and deposition and eroded particle transport. In this study, the physics-based Surface Soil Erosion Model (SSEM) was upgraded based on field survey information to produce sediment yield at the watershed scale. The modified model (hereafter MoSE) adopted new algorithms on rainfall kinematic energy and surface flow transport capacity to simulate soil erosion more reliably. For model validation, we applied the model to the Doam dam watershed in Gangwon-do and compared the simulation results with the USLE outputs. The results showed that the revised physics-based soil erosion model provided more improved and reliable simulation results than the USLE in terms of the spatial distribution of soil erosion and deposition.

• 한국작물학회지
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• 제40권3호
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• pp.278-284
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• 1995

본 연구는 토성별 지하수위가 밀, 보리의 생산물 종실의 품질 및 발아와 효소활성에 미치는 영향 등을 추구함으로서 적정지하수위와 지하수위에 따른 피해 정도를 구명 평가하고자 실시하였다. 올보리와 그루밀을 공시하여 1992년 10월 ~ 1993년 6월에 걸쳐 대형포트(550 liter) 시험을 수행하였다. 토성을 식양토와 사양토로 조성하여 전 생육기에 걸쳐 지하수위가 20, 30, 40, 50, 70cm가 되도록 조절하고 비가림 재배를 실시하였는데 그 결과를 요약하면 다음과 같다. 1. 정립비율과 종보비중은 토성과 지하수위에 따른 영향이 일정하지 않았으며 1,000립중은 보리와 밀 모두 지하수위가 낮아짐에 따라 증가하였고 토성에 따른 차이는 미미하였다. 2. 조단백 함량은 보리와 밀 모두 지하수위가 높아질수록 많아졌으며 특히 밀에서 뚜렷하게 나타났다. 토성에 따른 조단백 함량의 변화는 지하수위에 따른 영향보다 적었으며 사양토에서의 것이 식양토의 것보다 높은 경향이었으나 그 차이는 적었다. 3. 조지방 함량은 보리와 밀 모두 지하수위가 높아질수록 낮아졌으며 사양토에서의 조지방 함량이 높은 경향으로 나타났다. 4. 회분 함량은 보리와 밀 모두 지하수위가 높아질수록 낮아졌으며 특히 사양토에서 그 경향이 뚜렷하였다. 5. 밀의 제분율은 토성에 따른 차이는 없었으며 지하수위 20cm에서 종실 제분율이 65% 정도로 나타났고 지하수위 40cm 이하에서 제분율이 67% 이상으로 나타났다. 6. 2$0^{\circ}C$에서 3일 이내의 발아율에서 보면 보리와 밀 모두 모든 처리에서 95% 이상의 발아율을 보였으며 토성에 관계없이 지하수위 20cm에서 가장 낮은 발아율을 보였고 지하수위가 낮아질수록 발아율도 높아졌다. 7. 보리에서 24시간 이내의 발아율에서는 일정한 경향을 나타내지 않았으나 48시간 이내의 발아율에서는 사양토의 지하수위 20cm 처리를 제외하고는 89% 이상의 발아율로 나타나 48시간 이내에 대부분이 발아하는 발아세를 보였다. 8. 보리 맥아에서의 당화력(diastic power)은 지하수위 20cm 처리구에서 가장 낮게 나타났고 지하수위 30cm 이하 처리에서의 당화력의 차이는 현저하지 않았으며 토성에 따른 맥아 당화력의 차이는 나타나지 않았다.

• 한국물환경학회지
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• 제24권5호
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• pp.569-580
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• 2008

In this study, area-weighted slope and slope length module, considering measured field slope and slope length of the agricultural fields within the subwatershed, was developed using the ArcView Avenue programming to reflect the field topography of the Soil and Water Assessment Tool (SWAT) HRU in simulating the hydrology and water quality. Flow and sediment yield estimated values of the SWAT were compared with and without applying area-weighted slope and slope length module, developed in this study. There was 103% increases in estimated sediment with area-weighted slope and slope length module for the study watershed. The soil erosion and sediment yield from only agricultural field in Hae-an watershed was also assessed. There are 111% increase in estimated soil erosion and 112% increase in estimated sediment by applying area-weighted slope and slope length module. This study shows that the area-weighted slope and slope length module needs to be utilized in estimating the HRU field slope and slope length for accurate estimation of soil erosion and nonponit source pollutant modeling with the SWAT although it is not feasible to measure topographic information for every agricultural fields within the watershed. The area-weighted slope and slope length module can be used in identifying soil erosion hot spot areas for developing cost effective and efficient soil erosion management practices.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.15-18
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• 2001

Sixty natural springs and wells used as community facilities for drinking water are developed along mountain climbing way of suburban area and residential area in Daejeon City. In this study, the seasonal variation of their water quality and hydrochemical characteristics were investigated. Some natural springs are vulnerable to bacilli contamination because of their short residence time and shallow circulation in subsurface environment. The waters show hydrochemical types of Ca-HCO$_3$ and Na-HCO$_3$, and are characterized by low electrical conductance and weak acidic pH.