• Title/Summary/Keyword: 토심

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The Classification and Interpretation of Korean Soils Derived from Sedimentary Rocks using Multidimensional Scaling (다차원척도법을 이용한 우리나라 퇴적암 유래토양의 분류 및 해설)

  • Sonn, Yeon-Kyu;Seo, Myung-Chul;Park, Chan-Won;Hyun, Byung-Keun;Zhang, Yong-Seon
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.6
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    • pp.387-392
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    • 2008
  • It is very important to characterize five major properties of topography, drainage class, soil texture, available soil depth, and gravel content for soil survey. We used multidimensional scaling method for analyzing five major properties for the soils originated from sedimentary rocks to understand their relationships. We simplified 5 major characteristics on soils derived from sedimentary rocks. That is, topographic factor was 15 to 9, soil texture was 32 to 6, drainage class was 6 to 5, available depth was 4, and gravel content was 3. For the viewpoint of eigenvector, from dimension 2, 3 to dimension 1, 4, mountain soils and more fine soils dominated. By eigenvalue, there was no tendency, but in details, was some tendency between small groups. Like this, closely observe exceptional distribution of soils, we need improved intra-group homogeneity based on weight control of soil factor, addition and subtraction of soil factors. Also, we carefully analyzed soil characteristics involved intra-group, then we need reconsideration of past classification units.

Changes of Soil Salinity due to Flooding in Newly Reclaimed Saline Soil (신간척지 토양에서 담수에 의한 토양염도 변화에 대한 개관)

  • Ryu, J.H.;Yang, C.H.;Kim, T.K.;Lee, S.B.;Kim, S.;Baek, N.H.;Choi, W.Y.;Kim, S.J.;Chung, D.Y.
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.spc
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    • pp.45-46
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    • 2009
  • This study was carried out to identify the changes of EC during desalinization due to flooding in newly reclaimed saline soil. To do this, experimental plots were made of rotary tillage+water exchanging plot, flooding plot and rainfall flooding plot. In rotary tillage+water exchanging plot, drainage, rotary tillage and flooding were conducted at the interval of 7 days. In rotary tillage+water exchanging plot and flooding plot, plots were irrigated at the height of 10 cm. After 38 days desalinization, changes of EC values at top soil (0~20 cm) were as follows. In rotary tillage+water exchanging plot, EC decreased from $21.38dS\;m^{-1}$ to $2.16dS\;m^{-1}$ and in flooding plot, EC decreased from $13.97dS\;m^{-1}$ to $2.22dS\;m^{-1}$. In rotary tillage+water exchanging plot and flooding plot, EC values decreased below the EC criterion ($4.0dS\;m^{-1}$) of saline soil. In rainfall flooding plot, EC values decreased or increased according to amounts of rainfall and rainfall time. After 38 days, EC decreased from $16.7dS\;m^{-1}$ to $12.35dS\;m^{-1}$. In flooding plot, changes of EC due to soil depth were investigated. After 38 days desalinization, changes of EC due to soil depth were as follows. At 0~10 cm depth, EC value decreased from $13.08dS\;m^{-1}$ to $0.74dS\;m^{-1}$ (94.3% of salt was desalinized). At 10~20 cm depth, EC value decreased from $14.80dS\;m^{-1}$ to $3.69dS\;m^{-1}$ (75.2% of salt was desalinized). At 20~30 cm depth, soil was desalinized slowly compared with upper soil, EC value decreased from $13.57dS\;m^{-1}$ to $6.93dS\;m^{-1}$ (48.9% of salt was desalinized).

Atomic Absorption Spectrophotometric Analysis of Lead (Pb) in the Soils of Cropping Areas Near Highways (원자흡광법에 의한 고속도로변 경작지토양중의 납함량분석에 관한 연구)

  • Park Seung Heui
    • Korean journal of applied entomology
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    • v.18 no.1 s.38
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    • pp.43-48
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    • 1979
  • This study was conducted to detect lead which is exhausted with gas from running automobiles and is considered to accumulate in cropping lands. Soil samples were taken from uplands and paddy fields with different distance from highways. atonic absorption spectrophotometer was applied for analysis. Results obtained are summarized as follows: 1. In the areas of Seoul toll gate and Jookjeon, Gyeonggi province, soils of fields within $3\~5$ meters from highway appeared to contain $11\~110\;ppm$ of lead. On the other hand, soils outside of $3\~5$ meters showed only natural background level of lead. 2. The maximum concentration of lead in Hwoedeuk area (Choong-nam p개vince) was 16.3 ppm and those of Kimhae and Dongrae areas were about 12 ppm. Low concentration of $1\~4\;ppm$ was observed in the areas, south of Daejeon along the Honam and Namhae highways. 3. Lead seemed to accumulate in the soil surface within the range of 0 to 5 centimeters which anable to expect little translocation to deeper layer of the soil. 4. lost of arable lands locates at least 15 meters apart from highways so that lead concentrations were lower than expected. No damage could be speculated with the present concentration of lead analyzed. This does not deny the necessity to the long term dectect of the possible pollutant.

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Site and Soil Factors Affecting Early Growth of Larix kaempferi Trees Planted in Harvested Larix kaempferi Plantations (지황 및 토양 인자가 낙엽송 벌채지 내 낙엽송 조림목의 초기 생장에 미치는 영향)

  • Yang, A-Ram;Jeong, Jaeyeob;Cho, Min Seok
    • Journal of Korean Society of Forest Science
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    • v.107 no.1
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    • pp.35-42
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    • 2018
  • This study was carried out to investigate site and soil factors affecting growth of root collar diameter (RCD) and height (HT) of Larix kaempferi trees planted in harvested Larix kaempferi plantations. We were found effect factors of growth of RCD and HT using 15 of site and soil factors. And then we made the growth estimated equations of RCD and HT of 6-years-old L. kaempferi tree by the derived affecting factors. The growth of RCD was affected in order of available phosphorus (+), effective soil depth (+), organic matter (-), sand separate in soil (-), pH (-), and elevation (-), and the coefficient of determination ($R^2$) of the growth estimated equation of RCD was 0.51. The growth of HT was affected in order of effective soil depth (+), elevation (-) slope (-), and available phosphorus (+) and the $R^2$ of the growth estimated equation of HT was 0.46. The growth of RCD and HT were commonly affected by effective soil depth, available phosphorus, and elevation. Therefore, planting site of L. kaempferi should be considered the mainly effect factors in order to keep better early growth based on the current study.

Development of Prediction Technique of Landslide Hazard Area in Korea National Parks (국립공원의 산사태 발생 위험지역 예측기법의 개발)

  • Ma, Ho-Seop;Jeong, Won-Ok;Park, Jin-Won
    • Journal of Korean Society of Forest Science
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    • v.97 no.3
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    • pp.326-331
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    • 2008
  • This study was carried out to analyze the characteristics of each factors by using the quantification theory(I) for prediction of landslide hazard area. The results obtained from this study were summarized as follows; The stepwise regression analysis between landslide sediment ($m^3$ ) and environmental factors, factors affecting landslide sediment ($m^3$ ) were high in order of mixed (forest type), < 15 cm(soil depth), 801~1,200 m (altitude), $31{\sim}40^{\circ}$ (slope gradient), 46 cm < (soil depth), 1,201 m < (altitude) and s(aspect). According to the range, it was shown in order of soil depth (0.3784), altitude (0.2876), forest type (0.2409), slope gradient (0.1728) and aspect (0.1681). The prediction of landslide hazard area was estimated by score table of each category. The extent of prediction score was 0 to 1.2478, and middle score was 0.6239. Class I was over 1.1720, class II was 0.7543 to 0.1719, class III was 0.4989 to 0.7542 and class IV was below 0.4988.

Comparison of Hydrologic Soil Groups with Classification Method (분류방법에 따른 수문학적 토양유형 비교)

  • Jung, Kang-Ho;Hur, Seung-Oh;Sonn, Yeon-Kyu;Park, Chan-Won;Ha, Sang-Keun;Kim, Nam-Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.97-105
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    • 2007
  • 수문학적 토양유형은 복잡하게 세분되어 있는 토양의 종류를 수문학적인 목적에 따라 단순화하기 위해 만든 것으로 미농무성 토양보전국에서 고안한 개념이다. 우리나라 토양을 이 방법으로 구분하고자 하는 몇번의 시도가 있으며 그 중 대표적인 것이 정 등(1995)이 분류한 수문학적 토양군이다. 이는 토양의 침투 투수특성에 대한 실측자료가 부족한 우리나라의 실정을 감안하여 토성속(textural family), 배수등급(drainage class), 불투수층(impermeable layer), 투수성(permeability)의 네가지 토양특성을 분류특성으로 하여 각각에 1-4점 범위로 점수를 매긴 후 합산한 점수를 기준으로 수문학적 토양유형을 분류하는 것이다. 최근에는 토양의 한계침투속도에 따라 수문학적 토양유형을 분류하고자 하는 시도가 있으며 본 논문에서는 새로운 방법으로 분류할 때 기존의 방법과 어떠한 차이가 있는지 비교하고자 하였다. 정 등(1995)의 분류방법은 개념상 몇가지 문제점을 안고 있다. 먼저 토양의 수리특성은 같은 토성속이라 하여도 토양생성 과정과 토지이용 방법에 따라 그 차이가 매우 큼에도 불구하고 이에 대해 고려하지 못하였으며 다음으로 지표유거가 많아 배수가 양호한 토양의 강우 유출을 과소평가한다. 또한 얕은 토심에 존재하는 불투수층이 존재하는 경우 토양의 수리특성에 관계없이 적은 양의 강우에도 유출이 발생하므로 별도의 제한인자로 간주하여야 한다. 토양의 한계 침투속도를 이용한 분류방법은 이러한 문제점을 상당 부분 개선할 수 있다. 토양의 한계침투속도를 산정하기 위해 현장에서 지표 한계침투속도와 투수속도를 측정하였으며 이 자료를 확장하여 해석하기 위해 입자특성을 이용한 Pedo Transfer Function을 개발하였다. 토심 50 cm 포화시 토양 투수성을 한계 침투속도로 가정하였으며 50 cm 이내에 암반층과 지하수위가 존재할 경우 투수성에 관계없이 D유형으로 분류하였다. 새로운 방법으로 분류한 결과 기존의 분류와 몇가지 차이점이 발견되었다. 가장 큰 차이는 대부분의 논토양이 느린 한계침투속도의 영향으로 D유형에 속한 것이다. 산림토양과 밭토양은 기존 방법과 마찬가지로 A, B유형이 많았으며 암반층을 고려하기 전에는 기존 분류에 비해 강우 유출 가능성이 적은 쪽으로 평가되었다. 그러나 암반층이 존재하는 토양을 고려한 결과 A 또는 B 유형에 속하던 상당수의 산림토양이 새로운 분류에서 D유형으로 분류되었다. 지표 유거가 많아 배수등급이 매우양호로 분류되던 토양은 정 등(1995)의 분류와 비교하여 대부분 강우 유출 가능성이 큰 쪽으로 조정되었다. 새로운 수문학적 토양유형을 이용할 경우 낮은 토심에서 암반층이 발견되는 산림토양이 분포한 유역이나 산림, 밭 등에 식질 토양이 많이 분포하는 유역에서는 기존의 방법을 이용하는 것보다 강우 유출량이 높게 평가될 것으로 판단된다. 앞으로 강우 유출량 실측자료와의 비교를 통해 지속적인 보정을 하여야 할 것이며 특히 불투수층의 존재시 일괄적으로 D유형으로 분류된 토양의 경우 깊이에 따라 C 또는 D 유형으로 세분하여 조정할 필요가 있다.

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Analysis of Characteristics of Plant, Soil Physical and Chemical of Salix spp. on the Environment of Namgang Dam Reservoir (남강댐 수변구역 버드나무류 군락의 식생분석 및 토양의 이화학적 특성)

  • Park, Jae-Hyeon;Kim, Ki Heung;Lee, Seok Bae
    • Journal of Korean Society of Forest Science
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    • v.102 no.2
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    • pp.161-169
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    • 2013
  • This study was carried out to examine characteristics of physical and chemical current status and problems of Salix spp. communities based on growth characteristics by tree age and height of the tree species in around Namgang Dam reservoir area. Tree density in 4 survey areas was 5,284 trees/ha, but all areas need to control high tree density. Tree crown area in 4 survey areas was 9,786.4 $m^2/ha$ and crown area of Salix spp. was the most dominant among tree species in watershed of the Jinyang lake. Mean soil depth in 4 survey areas was 65.5 cm higher in the sedimental deposit soil (78 cm) than in forest soil (12.5 cm) near the watershed. Soil bulk density was also higher in the sedimental deposit soil than in forest soil because of poor porosity in the sandy sediment. Soil pH was higher in sedimental deposit soil (A, B horizon:pH 6.7) than in forest soil (A horizon:pH 5.3; B horizon:pH 5.2) because of originated from non-point source polution and detergent of domestic sewage. The results suggest that growth of Salix spp. could be poor because of low fertility with low cation exchange capacity in sedimental deposit soil.

Analysis of Characteristics of Landslide Susceptibility in Rugged Mountain Range in the Korean National Park (산악형 국립공원지역의 산사태 발생과 취약지역 특성 분석)

  • Lee, Sung-Jae;Lee, Eun-Jai;Ma, Ho-Seop
    • Journal of Korean Society of Forest Science
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    • v.108 no.4
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    • pp.552-561
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    • 2019
  • In korea, debris-flow disasters are induced by typhoon and localized torrential rainfall annually. These disasters are particularly severe in the Korean national park due to its geomorphological characteristics. This study was conducted to analyze the landslide characteristics and forest environmental factors of landslide areas located in rugged mountain range in the Korean national park (Mt. Seorak, Mt. Jiri, and Mt. Sobaek). Overall, landslides occurred at 474 sites. The average area of the landslide scar among these sites was 1,212 ㎡. The average landslide sediment was 1,389 ㎥, average landslide length was 75 m, and the average width was 12.9 m. The landslides frequently occurred in regions with igneous rock and coniferous forest. In addition, slope gradient degree (31°-40°), slope gradient direction (N), vertical slope (concave), cross slope (concave), altitude (401-800 m), position (middle), stream order (first order), forest type (mixed), parent rock (igneous), and soil depth (<46 cm). The relationship between landslide soil volume and environmental factors showed positive correlation. The variables of vertical slope (complex), altitude (<1,201 m), and soil depth (<46 cm) correlated significantly at 1 % level.

조경수의 병해충 - 밤나무에 피해를 주는 해충(1)

  • 최광식
    • Landscaping Tree
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    • s.88
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    • pp.8-11
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    • 2005
  • "가을을 상징하는 과일 중 밤나무의 밤 송아리처럼 가을을 대변하는 전령사는 드물 것이다. 가을 빛 영롱한 숲속에서 하늘과 당과 구름과 별과, 햇빛과 바람이 시를 읊고 있는 가을은 가시 속에 아롱진 꿈이 밤송이 되어 바람결에 빗방울처럼 떨어져도 겨울에 먹을 음식이 다람쥐와 청설모에게는 모자라는 안타까움이 인간의 욕심을 새삼 느끼게 하는 구나! 이렇게 우리에게 넉넉함과 즐거움을 주는 밤나무는 양수로서 바람이 적은 산록이나 저지대의 토심이 깊은 비옥토에서 잘 자라며, 맹아력이 좋고 수세가 강건하다. 과실은 예로부터 식용대용으로 각종음식을"

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