• 지질공학
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• 제17권4호
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• pp.665-671
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• 2007

본 연구에서는 독도 동도지역의 토질에 대한 공학적 특성을 조사하고, 산사태발생 가능성을 조사하였다. 이를 위하여 먼저 독도의 동도지역에 대한 토층분포 및 심도를 조사하고, 토질특성을 조사하기 위하여 시료를 채취하였다. 현장조사 결과 동도지역의 토층은 일부구간에 부분적으로 분포해 있으며, 토층의 심도는 $1{\sim}50cm$로 존재하고 있음을 알 수 있다. 토층의 심도는 대부분 구간에서 10cm내외로 존재하고 있다. 토질은 모암의 오랜 풍화로 인하여 생성된 풍화잔류토층으로서 썩은 나무뿌리 혹은 나뭇잎과 같은 유기물 성분이 매우 많이 함유되어 있음을 알 수 있다. 토질의 함수비는 평균 23.2%, 액성한계는 평균 42.2%이며, 비소성(non-plastic)인 것으로 나타났다. 그리고 대부분 입도분포가 불량한 모래로 분류할 수 있으며, 일부 롬(loam)이 함유되어 있음을 알 수 있다. 한편, 대상지역에 대한 토층의 발달양상을 파악하여 독도 동도지역의 산사태 발생가능성을 조사하였다. 대부분의 구간에서 토층의 심도가 매우 얕고 토층의 분포지역이 넓지 않은 것으로 나타났다. 따라서 산사태가 발생할 수 있는 조건을 만족하지 못하므로 산사태 발생가능성은 매우 낮은 것으로 예측할 수 있다.

• 한국토양비료학회지
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• 제49권2호
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• pp.200-207
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• 2016

To add new groundwater standard, 7 candidate materials (copper, zinc, selenium, manganese, iron, chromium, aluminum) were calculated by CROWN (Chemical Ranking Of groundwater pollutaNts). Copper and zinc were selected as groundwater candidates through the process and monitored total 430 samples for 2 years with 113 groundwater sampling sites. In this study, geological distribution characteristics (igneous rock, metamorphic rock, sedimentary rock) of copper and zinc were evaluated and the geological background levels obtained by a cumulative probability distribution and pre-selection methods were compared. In the results, the highest average concentrations of the copper and zinc were observed both in the igneous rock. The detection concentration ranges of copper and zinc in 430 groundwater samples were $0.002{\sim}0.931mg\;L^{-1}$, and $0.002{\sim}32.293mg\;L^{-1}$, respectively. In addition, detection concentration ranges of copper and zinc were $0.002{\sim}0.931mg\;L^{-1}$, $0.002{\sim}32.293mg\;L^{-1}$ in the igneous rock, $0.002{\sim}0.134mg\;L^{-1}$, $0.004{\sim}7.038mg\;L^{-1}$ in the metamorphic rock and $0.002{\sim}0.008mg\;L^{-1}$, $0.003{\sim}3.948mg\;L^{-1}$ in the sedimentary rock, respectively. As a result of the background concentrations with two methods, zinc concentrations with the pre-selected method are comparatively higher than that of the others with the cumulative distribution.

• 한국작물학회지
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• 제43권1호
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• pp.38-43
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• 1998

This study examined root growth and distribution under the direct seeding of rice cultivars developed in Korea, Japan, and the U.S. Cultivars from the U.S., especially 'M202' and 'Caloro', had a high ratio of the dry matter partitioning for root and top plant components. Caloro had high root and top growth. 'Koshihikari' from Japan showed the lowest ratio of R/T (root/total dry matter) due to the small amount of root and top plant growth. Most Japanese cultivars except transplanted 'Hatsuboshi' showed low ratio of R/T. Patterns of root distribution for each soil block were recorded by the root box-pin board method. Roots of all cultivars were distributed in blocks A, C, and E in the middle of box, i.e., just below the plant base. Roots of 'Dongjin', M202, and Caloro were distributed deeper than the others. Roots of transplanted Hatsuboshi developed much better than direct seeded Hatsuboshi. Total root weight density was highest in Caloro followed by Dongjin, 'Gancheok', 'Calrose', and the others. The root density of Caloro was twice as much as those of the others except Dongjin. According to cumulative percentages of root distribution on each soil layer, roots of most cultivars were distributed below 20cm. The U.S. cultivars showed vertically well developed root systems as compared to others. A large amount of roots were distributed in the top 15cm of soil layer for Hatsuboshi and Koshinikari, and their root systems appeared to be shallow. In contrast, the rates of root distribution in the top 10cm of soil layer were low for Dongjin, Calrose, and Caloro. These cultivars had relatively deep root systems.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.390-399
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• 2019

Background: The Northern Hemisphere forest ecosystem is a major sink for atmospheric carbon dioxide, and the subalpine zone stores large amounts of carbon; however, their magnitude and distribution of stored carbon are still unclear. Results: To clarify the carbon distribution and carbon budget in the subalpine zone at volcanic Jeju Island, Korea, we report the C stock and changes therein owing to vegetation form, litter production, forest floor, and soil, and soil respiration between 2014 and 2016, for three subalpine forest ecosystems, namely, Abies koreana forest, Taxus cuspidata forest, and Juniperus chinensis var. sargentii forest. Organic carbon distribution of vegetation and NPP were bigger in the A. koreana forest than in the other two forests. However, the amount of soil organic carbon distribution was the highest in the J. chinensis var. sargentii forest. Compared to the amount of organic carbon distribution (AOCD) of aboveground vegetation (57.15 t C ha^-1) on the subalpine-alpine forest in India, AOCD of vegetation in the subalpine forest in Mt. Halla was below 50%, but AOCD of soil in Mt. Halla was higher. We also compared our results of organic carbon budget in subalpine forest at volcanic island with data synthesized from subalpine forests in various countries. Conclusions: The subalpine forest is a carbon reservoir that stores a large amount of organic carbon in the forest soils and is expected to provide a high level of ecosystem services.

• 지질공학
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• 제32권2호
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• pp.241-255
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• 2022

본 연구에서는 예천지역의 화강풍화토에 대하여 KS F 2302의 체 분석 방법과 규정에 준하여 체분석 시험을 수행하고, 물 세척시 발생되는 흙의 입자분리와 입도분포 변화의 특성을 비교 분석하였다. 광학현미경에 의한 영상이미지 분석결과 흙입자가 물에 의해 더 작은 입자로 분리됨을 확인하였고 입도분포곡선의 변화를 5가지 지표값으로 산출한 결과 세립분(0.075 mm)의 증가량은 13.67%, 임의 입경(0.25 mm)의 증가량은 19.44%, 입도분포곡선의 최대통과율폭(B_M)은 #30 체에서 21.08%가 증가되었고 입도분포곡선의 이동면적(A)은 69.28%·mm로 분석되었으며 평균입경(D₅₀)은 0.663 mm가 감소되었다. 이러한 결과는 물 세척을 수행하는 것이 세립토의 함량이 실제보다 과소평가 되는 것을 막을 수 있는 효과적인 방법임을 의미한다.

• 한국환경과학회지
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• 제16권12호
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• pp.1451-1462
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• 2007

Heavy metal concentrations in the soil were investigated for the abandoned Samkwang metal mine, Cheongyang-Gun, Chungnam Province, Korea. The concentrations of heavy metal(As, Cd, Cu, Ni, Pb, Zn) were determined in mine soils collected at the abandoned mine sites to obtain a general classification and specification of the pollution in this highly polluted region. The results estimated with the normal test and basis statistic on the central tendency and variation showed that the distribution of heavy metal concentration had significantly different at the range of all locations. The range of spatial distribution on the relationship of heavy metal concentration and pH was $4.8{\sim}8.8$ and heavy metal concentration on the type of land use was highest in forest land, and also Ni and Zn in farm and rice field showed the high concentration. The distribution of heavy metal concentration on the depth of a soil showed that the metal concentrations in subsoil were higher than of those in surface soil, while the concentration of Cu and Ni had no significant difference on the depth of soil. Results from the correlation analysis using the data except the extreme and unusual data revel that Zn-Cd(r=0.867), Zn-As(r=0.797), Zn-Pb(r=0.764), Cu-Cd(r=0.673), Cu-As(r=0.614) and Zn-Ni(r=0.605) were the most important parameters in assessing variations of heavy metal in soil. To discriminate pattern differences and similarities among samples, principal factor analysis(PFA) and cluster analysis(CF) were performed using a correlation matrix. This study suggests that PFA and CF techniques are useful tools for identification of important heavy metal and parameters. This study presents the necessity and usefulness of multivariate statistical assessment of complex databases in order to get better information about the quality of soil and gives the basis information to clean up the abandoned mine sites.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권3호
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• pp.22-40
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• 2022

The goal of this study was to estimate the possible scattering distance of deicer from the highway and the impact range of deicer on soil quality in terms of plant growth. Among the major elements (Ca²⁺, Cl^- and Na⁺) of deicer, Ca²⁺and Cl^- are usually applied as fertilizer to soil. Therefore both elements (Ca²⁺and Cl^-) were not appropriate for a tracer of deicer at the agricultural area. In this study, SAR (sodium adsorption ratio) of soil was proposed as an alternative tracer to confirm the distribution of the deicer around the highway areas. Because deicer is the main anthropogenic source of Na⁺ around the highway areas and does harm to the physical properties of soil and plant growth through the destruction of soil aggregate, SAR would be an recommendable tracer to access the distribution of deicer as well as adverse effect on soil quality at highway areas. The influence range of deicer based on SAR of soil was estimated to be less than 20 m distance from the highway even though the possible flying distance of deicer was found to be more than 100 m from the highway. However the deicer seriously deposited within 10 m from the highway.

• 한국토양비료학회지
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• 제44권5호
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• pp.696-701
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• 2011

전북지역 과수원 토양 110개소를 대상으로 토양특성이 미생물분포에 미치는 영향을 조사하였다. 토양 중 미사함량이 많아질수록 호기성세균, 곰팡이, 미생물 biomass C 함량은 증가하였고, 탈수소효소 활성은 토성에 따라 차이가 없었다. 지형에 따른 미생물분포, 미생물의 biomass C 함량, 탈수소효소 활성은 차이가 없었고, 과수종류에 따라 coliform group은 배와 포도 재배지에서 각각 $133.0{\times}10^3\;CFU\;g^{-1}$, $107.4{\times}10^3\;CFU\;g^{-1}$으로 가장 높은 수준을 보였다. 과수재배기간이 길어질수록 미생물 밀도는 감소하는 것으로 나타났다. 토양 pH, 유기물, 치환성 Mg 함량은 모든 미생물분포와 정의 상관관계를 보였고, Bacillus sp.는 조사한 모든 화학성분과 정의 관계를 보였다. 토양미생물의 biomass C 함량과 탈수소효소 활성은 유기물과 치환성 Ca 함량에 대해 고도의 유의성 (p<0.01)을 보였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권6호
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• pp.72-79
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• 2014

Cavitation generated by ultrasonic irradiation can enhance the diffusional transport of organic contaminants from soil surfaces or pores. Therefore, ultrasound soil washing can be an alternative of traditional soil washing process. In this study, soil was artificially contaminated with n-tetradecane, n-hexadecane and phenanthrene. A plate type ultrasonic reactor at 25 kHz frequency and 1000W power was used for laboratory soil washing experiments. Ultrasonic soil washing efficiency was compared with those of traditional soil washing using mechanical mixing. Various operational parameter such as soil/liquid ratio, irradiation time, particle size, and soil organic matter content was tested to find out the optimum condition. It was found that ultrasonic soil washing demonstrates better performance than mechanical soil washing. Optimum soil:liquid ratio for ultrasonic soil washing was 1 : 5. Desorption of organic contaminants from soils by ultrasonic irradiation was relatively fast and reached equilibrium within 10 minute. However, decrease in the soil particle sizes by ultrasonic irradiation results in re-adsorption of contaminants to soil phase. It was also observed that soil particle size distribution and soil organic matter content have significant effects on the efficiency of ultrasonic soil washing.

• The Korean Journal of Ecology
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• 제20권1호
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• pp.1-8
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• 1997

This study was conducted to investigate the distributions of the native and introduced dandelins in the western Kyonggido area and to determine the environmental factor influencing distribution of dandelions. One hundered and thirty seven study sites were randomly selected along roadsides in urban areas, arable lands, apartment areas and industry regions, and vegetation, dandelion's seed characters and soil acidity were sureyed. Throughout the areas the introduced dandelions were more widely distributed than the native ones. The native dandelions were scarcely distributed in the developed areas and roadsides. The introduced dandelions were dominantly distributed in the new environments where soils were alkalized by the trban development, road pavement, and construction of new buildings, while the native ones were mostly distributed in the rural area with weakly acid soil. The seed production of the introduced ones were two times more than that of the native ones. The seed of the introduced ones were lighter than that of the native ones. The introduced ones yield seeds more than four times a year. These results suggested the urbanization and the seed characters to bet the two dominant factors influencing the distribution of dandelions.