• Title/Summary/Keyword: 표토 조건

Search Result 48, Processing Time 0.034 seconds

A Study on the Actual Condition of Topsoil Management at River Restoration Projects (하천복원현장에서 표토관리 실태에 관한 연구)

  • Cho, Yong-Hyeon;Lee, Jong-Mun;Kim, Won-Tae;Yoon, Yong-Han;Kang, Hee-Kyoung;Park, Bong-Ju;Yoon, Taek-Seong;Jang, Kwang-Eun;Shin, Kyung-Jun;Eo, Yang-Joon;Kwak, Moo-Young;Song, Hong-Seon
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.41 no.1
    • /
    • pp.34-43
    • /
    • 2013
  • This study aimed to research and analyze the real condition of topsoil management of river development field as a significant case among domestic development fields for topsoil preservation. Through survey with experts, we understood the real condition and problems of topsoil management during river development. In order to verify this, we analyzed the characteristics of soil before and after development focusing on the rivers recently completed as an ecological river restoration project, supervised by Ministry of Environment among domestic river improvement projects. The study results are like below. First, experts preferred collecting and reusing topsoil as the best method to maintain and improve soil for plant growth. Second, realistically collecting and reusing topsoil is not fully conducted due to economical issues and inconvenience in construction. In the soil condition, third, the contents of elements necessary for plant growth like organic matter and total nitrogen declined overall after development.

Studies on Restoration of Forest-Floor Vegetation Devastated by Recreational Trampling (I) -Seeding, Fertilizing and Soil Surface Treatment Effect on Restoration of Forest-Floor Vegetation- (답압(踏壓)으로 훼손(毁損)된 임간나지(林間裸地)의 임상식생복원(林床植生復元)에 관한 연구(硏究)(I) -임상식생복원(林床植生復元)에 미치는 파종(播種), 시비(施肥) 및 표토처리효과 (表土處理效果)-)

  • Oh, Koo Kyoon;Woo, Bo Myeong
    • Journal of Korean Society of Forest Science
    • /
    • v.81 no.1
    • /
    • pp.53-65
    • /
    • 1992
  • For elucidating effective methods of restoration of forest recreational sites where management goals are maintaining naturalness and conserving natural ecosystem, seeding, fertilization and soil surface treatment were used for four years at the devastated forest-floor. For restoration of forest-floor vegetation, factorial experiment was used with a split plot design(main plot : fertilization, subplot : soil surface${\times}$seeding) and a randomized complete block design (fertilization${\times}$seeding) at the Kwanaksan Aboretum, Anyang, Kyonggido. Results were summarized as follows : Soil surface softening with tipping and ripping and straw-mat mulching (70% coverage) treatment was effective on germination, survival and growth of seeded vegetation at devastated forest-floor. Especially, straw-mat mulching treatment was effective on soil surface stabilization and seedling's survival at eroded soil surface, while complete soil surface softening treatment was effective on germination, survival and early growth of tree species of late-successional series. Introducing seeds of native species of pioneer or early-successional series, with good growth capability in barren soil was effective on rapid restoration in devastated forest-floor with its soil surface previously compacted and its surviving seeds washed away. When the seeding and straw-mat mulching after partial soil surface softening with tipping and ripping treatment were employed, it took about three years to restore the devastated forest-floor where surface erosion had been undertaken for an extended period of time and where naturally surviving seeds of native species had been washed away. Softening treatment of soil surface was effective for about two years, and seeding and soil surface treatment increased number of seedlings and improved soil surface environment through fixing of movement of the fallen leaves. Fertilizing effect was not oberserved, mainly due to seeding exposure and poor physical condition including soil surface erosion, low soil water potential and drought, etc, at the field experimental site. However, application of nitrogen and phosphate fertilizers was effective on seedling survival of the species in late-successional series, while lime application adversely affected the seedling survival.

  • PDF

Loss and Sediment Estimation for the Precise Monitoring of Surface Soil (표토의 정밀 모니터링을 위한 유실 및 퇴적량 산정)

  • Kang, Young Mi;Kang, Joon Mook
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.1D
    • /
    • pp.141-147
    • /
    • 2006
  • Soil losses are occurred by rainfall has caused productivity decline of a fertile surface soil and inflow sediment on Dam reservoir which are the main reasons of the decrease of storage volume and difficulty of water management. In this study, the amount and location of soil losses which were evaluated using USLE(Universal Soil Loss Equation) were applied on soil, landcover, and topographical conditions on the basis of satellite images and GIS. Furthermore, it was possible to evaluate the amount of riverbed sediments using echo-sounder and sediment rate were analyzed by comparing with soil losses.

Impact of landuse and slope on soil erosion (토지이용과 경사가 토양침식량 미치는 영향)

  • Kim, Seong Won;Lee, Dae Eop;Yu, Wan Sik;Lee, Gi ha
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2020.06a
    • /
    • pp.337-337
    • /
    • 2020
  • 기후, 지형, 토지이용 등 다양한 환경요인들의 조건에 따라 동일한 강수량에도 표토침식량이 다르게 발생한다. 지형과 토지이용은 인위적인 개발에 의해 크게 변화될 수 있지만 인위적인 요소를 제외한다면, 지형변화는 매우 느리게 발생하며 토지이용은 계절적으로 변화하게 된다. 우리나라 대부분의 토양침식은 강우-유출에 의한 침식(water erosion)으로 지표를 흘러가는 유체에 함께 표토를 구성하는 토양 입자들이 이동하면서 발생하게 되는데 지표면을 덮고 있는 피복과 사면경사에 큰 영향을 받게 된다. 본 연구에서는 강우와 지표흐름을 고려할 수 있는 물리적 기반 토양침식모형을 이용하여 토지이용과 경사에 따라 토양침식량과 공간적 침식분포가 어떻게 변화되는지 분석하고자 하였다.

  • PDF

Analysis of the Efficiency of Investment Made on Species of Major Economic Importance (몇 주요경제수종(主要經濟樹種)에 대(對)한 경제효과(經濟効果) 분석(分析))

  • Yim, Kyong-Bin
    • Journal of Korean Society of Forest Science
    • /
    • v.13 no.1
    • /
    • pp.41-66
    • /
    • 1971
  • 본연구에 있어서 낙엽송, 소나무, 잣나무, 밤나무 그리고 포풀러를 주요 조림수종으로 취급해서 이들 수종(樹種)을 용재림생산(用材林生産) 또는 채실림(採實林)의 목적(目的)으로 경영(經營)한다하는 합리적(合理的)이라고 생각되는 몇 전제조건(前提條件)을 세워서 투자(投資)에 대한 수입률(收入率)을 분석(分析)해 보았다. 수입(收入)에 관여(關與)하는 인자(因子)에는 특히 토지조건(土地條件) (비옥도(肥沃度) 수분(水分), 경사(傾斜), 표토조건(表土條件) 등), 경영방법(經營方法)등에 따라 변화(變化)할 가능성(可能性)이 다분(多分)히 많은 것이지만 일단 일반수준(一般水準)을 생각해서 분석(分析)을 했다. 시대(時代)의 변천(變遷)에 따라 투자분석(投資分析)에 쓰여지는 인자(因子)의 값은 따라서 달라질 것이나 현시(現時)에 있어서의 어떤 수준(水準)이란 것을 고찰(考察)해 본 것이다.

  • PDF

Rehabilitation Measures for Disturbed Subalpine Meadows in Chirisan National Park, Republic of Korea (지리산 국립공원 아고산대 황폐나지의 식생복원공법 개발)

  • 오구균;우보명;김동완
    • Korean Journal of Environment and Ecology
    • /
    • v.11 no.1
    • /
    • pp.37-45
    • /
    • 1997
  • The Nogodan area has maintained the subalpine meadows(m.s.l. 1,500m) in Chirisan National Park. A field experiment including fertilizing, introducing plants and mulching treatment was conducted for three years at artificially disturbed subalpine meadows in the Nogodan to find out effective revegetation measures. Factorial experiment(2*2*2) was applied to the subsoil sites with ten percent hillslope and the topsoil sites with forty percent hillslope. Regardless of site conditions, survival rates of plants were more effective in on-site conditions, showed significant increase in the number of individuals and crown coverage of vegetation, but mulching treatment did not show a significant effect.

  • PDF

Analyzed Change of Soil Characteristics by Rainfall and Vegetation (강우 및 식생에 의한 토질특성 변화 분석)

  • Lee, Moon-Se;Kim, Kyeong-Su;Song, Young-Suk;Ryu, Je-Cheon
    • The Journal of Engineering Geology
    • /
    • v.19 no.1
    • /
    • pp.33-41
    • /
    • 2009
  • In this study, some changes of soil characteristics in a field were analyzed to investigate the effect of heavy rainfall during rainy season. The heavy rainfalls were often induced geohazards like landslides. To do this, the reaching rainfall in the ground surface was investigated according to a condition of vegetation, and the change of soil characteristics induced by infiltrating rainfall was analyzed. The study site is a natural terrain located in Daedeok Science Complex. This site has same geology and soil condition whereas it has different vegetable condition. The rainfall records during the rainy season of 2006 and 2007 were selected. The rainfall records are based on the measuring date from Daejeon Regional Meteorological Administration adjacent to the study site. Also, the rainfall records according to the condition of vegetation were measured using rainfall measuring device made by ourselves. The soil tests were carried out about soil specimen sampled before and after rainfall, and then the change of soil characteristics related to rainfall and vegetation were analyzed. As the result, the density of vegetation was influenced by reaching rainfall quantity in the ground surface, and its influence intensity was decreased with rainfall intensity and rainfall duration. Also, it shows that degree of saturations, water contents, liquidities and shear resistances are directly influenced by heavy rainfalls.

Characteristics and classification of paddy soils on the Gimje-Mangyeong plains (김제만경평야(金堤萬頃平野)의 답토양특성(沓土壤特性)과 그 분류(分類)에 관(關)한 연구(硏究))

  • Shin, Yong Hwa
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.5 no.2
    • /
    • pp.1-38
    • /
    • 1972
  • This study, designed to establish a classification system of paddy soils and suitability groups on productivity and management of paddy land based on soil characteristics, has been made for the paddy soils on the Gimje-Mangyeong plains. The morphological, physical and chemical properties of the 15 paddy soil series found on these plains are briefly as follows: Ten soil series (Baeggu, Bongnam, Buyong, Gimje, Gongdeog, Honam, Jeonbug, Jisan, Mangyeong and Suam) have a B horizon (cambic B), two soil series (Geugrag and Hwadong) have a Bt horizon (argillic B), and three soil series (Gwanghwal, Hwagye and Sindab) have no B or Bt horizons. Uniquely, both the Bongnam and Gongdeog series contain a muck layer in the lower part of subsoil. Four soil series (Baeggu, Gongdeog, Gwanghwal and Sindab) generally are bluish gray and dark gray, and eight soil series (Bongnam, Buyong, Gimje, Honam, Jeonbug, Jisan, Mangyeong and Suam) are either gray or grayish brown. Three soil series (Geugrag, Hwadong and Hwagye), however, are partially gleyed in the surface and subsurface, but have a yellowish brown to brown subsoil or substrata. Seven soil series (Bongnam, Buyong, Geugrag, Gimje, Gongdeog, Honam and Hwadong) are of fine clayey texture, three soil series (Baeggu, Jeonbug and Jisan) belong to fine loamy and fine silty, three soil series (Gwanghwal, Mangyeong and Suam) to coarse loamy and coarse silty, and two soil series (Hwagye and Sindab) to sandy and sandy skeletal texture classes. The carbon content of the surface soil ranges from 0.29 to 2.18 percent, mostly 1.0 to 2.0 percent. The total nitrogen content of the surface soil ranges from 0.03 to 0.25 percent, showing a tendency to decrease irregularly with depth. The C/N ratio in the surface soil ranges from 4.6 to 15.5, dominantly from 8 to 10. The C/N ratio in the subsoil and substrata, however, has a wide range from 3.0 to 20.25. The soil reaction ranges from 4.5 to 8.0. All soil series except the Gwanghwal and Mangyeong series belong to the acid reaction class. The cation exchange cpacity in the surface soil ranges from 5 to 13 milliequivalents per 100 grams of soil, and in all the subsoil and substrata except those of a sandy texture, from 10 to 20 milliequivalents per 100 grams of soil. The base saturation of the soil series except Baeggu and Gongdeog is more than 60 percent. The active iron content of the surface soil ranges from 0.45 to 1.81 ppm, easily-reduceable manganese from 15 to 148 ppm, and available silica from 36 to 366 ppm. The iron and manganese are generally accumulated in a similar position (10 to 70cm. depth), and silica occurs in the same horizon with that of iron and manganese, or in the deeper horizons in the soil profile. The properties of each soil series extending from the sea shore towards the continental plains change with distance and they are related with distance (x) as follows: y(surface soil, clay content) = $$-0.2491x^2+6.0388x-1.1251$$ y(subsoil or subsurface soil, clay content) = $$-0.31646x^2+7.84818x-2.50008$$ y(surface soil, organic carbon content) = $$-0.0089x^2+0.2192x+0.1366$$ y(subsoil or subsurface soil, pH) = $$-0.0178x^2-0.04534x+8.3531$$ Soil profile development, soil color, depositional and organic layers, soil texture and soil reaction etc. are thought to be the major items that should be considered in a paddy soil classification. It was found that most of the soils belonging to the moderately well, somewhat poorly and poorly drained fine and medium textured soils and moderately deep fine textured soils over coarse materials, produce higher paddy yields in excess of 3,750 kg/ha. and most of the soils belonging to the coarse textured soils, well drained fine textured soils, moderately deep medium textured soils over coarse materials and saline soils, produce yields less than 3,750kg/ha. Soil texture of the profile, available soil depth, salinity and gleying of the surface and subsurface soils etc. seem to be the major factors determining rice yields, and these factors are considered when establishing suitability groups for paddy land. The great group, group, subgroup, family and series are proposed for the classification categories of paddy soils. The soil series is the basic category of the classification. The argillic horizon (Bt horizon) and cambic horizon (B horizon) are proposed as two diagnostic horizons of great group level for the determination of the morphological properties of soils in the classification. The specific soil characteristics considered in the group and subgroup levels are soil color of the profile (bluish gray, gray or yellowish brown), salinity (salic), depositonal (fluvic) and muck layers (mucky), and gleying of surface and subsurface soils (gleyic). The family levels are classified on the basis of soil reaction, soil texture and gravel content of the profile. The definitions are given on each classification category, diagnostic horizons and specific soil characteristics respectively. The soils on these plains are classified in eight subgroups and examined under the existing classification system. Further, the suitability group, can be divided into two major categories, suitability class and subclass. The soils within a suitability class are similar in potential productivity and limitation on use and management. Class 1 through 4 are distinguished from each other by combination of soil characteristics. Subclasses are divided from classes that have the same kind of dominant limitations such as slope(e), wettness(w), sandy(s), gravels(g), salinity(t) and non-gleying of the surface and subsurface soils(n). The above suitability classes and subclasses are examined, and the definitions are given. Seven subclasses are found on these plains for paddy soils. The classification and suitability group of 15 paddy soil series on the Gimje-Mangyeong plains may now be tabulated as follows.

  • PDF

Analysis of Ground Subsidence on Gyochon Residential Region of Muan City (무안 교촌리주거지역 지반침하 안정성 분석)

  • Han, Kong-Chang;Cheon, Dae-Sung;Ryu, Dong-Woo;Park, Sam-Gyu
    • Tunnel and Underground Space
    • /
    • v.17 no.1 s.66
    • /
    • pp.66-74
    • /
    • 2007
  • The analysis of ground subsidence stability was conducted for the residential area located on the limestone corrosion zone. For the investigation of the cavity distribution in limestone region, various geophysical investigations such as electroresistivity tomography, electromagnetic prospecting are carried out. Geotechnical field tests with drilling are also carried out for the evaluation of the ground characteristics. Based upon their results, numerical modeling is performed for the simulation and prediction of the ground subsidence with the conditions of cavity geometry and groundwater level. The main factor to cause the ground subsidence is estimated as the draw down of the groundwater level below soil overburden, which disturbs the mechanical equilibrium of ground and drives washing away the overburden soil through the cavity and solace subsidence. It seemed that it is essential to maintain the groundwater level continuously above the shallow cavity for the prevention of the ground subsidence on the limestone corrosion zone.

Study of the USLE P factor in USLE Equation (범용토양유실량 산정공식 USLE P factor에 관한 연구)

  • Sung, Yunsoo;Lee, Doungjun;Han, Jeongho;Lee, Seoro;Lim, Kyoung Jae
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2016.05a
    • /
    • pp.399-399
    • /
    • 2016
  • 현대 인류는 비약적인 경제성장으로 인하여 급격한 도시화와 산업화를 이루었다. 하지만 이러한 성장을 위해 수반되는 자원개발 및 생활환경조성으로 인한 토지개발이 진행되어 많은 양의 토양이 유실되고 있다. 토양유실을 관리하기 위해서는 모니터링을 통해 관리하는 방법과 모형을 통해 유실되는 토양의 양을 산정하여 관리방안을 제시하는 방법이 있다. 현재 전 세계적으로 사용되고 있는 범용토양유실량 산정공식(USLE)은 사용상의 편리성과 연간 토양유실량을 산정할 수 있는 이점이 있다. 뿐만 아니라 국내의 환경부에서는 USLE 공식을 적용한 '표토 침식 현황에 관한 고시'를 제정하여 유실되는 표토를 관리하고 있다. 하지만 USLE 공식을 구성하고 있는 인자 중 P factor는 경사도만을 고려하여 인자 값을 제시하고 있으며, 밭에 적용된 관리방법과 작물, 경운방법 등을 고려하지 않아 방법에 차이에 따른 발생되는 토양유실량에 차이가 발생하게 된다. 이러한 문제점을 고려하여 경작지의 경사도와 적용된 관리방안을 복합적으로 고려한 P factor 선정 체계가 필요한 시점이다. 따라서 본 연구에서는 실제 경작지 조사를 통해 경작지 별 관리방안과 경사도를 고려한 P factor를 제안하고자 한다. 관리방안과 경사도를 복합적으로 고려한 P factor를 제안하기 위해 선정된 유역은 강원도 양구군 해안면 유역과 자운리 유역, 안동시 임동면 반변천 상류 유역을 선정하여 위치하고 있는 밭에 대한 현장조사를 진행하였다. 조사항목은 경작지의 경사도, 재배작물, 관리방법, 경운방법 등을 조사하였으며, 이를 바탕으로 경사도와 관리방법을 복합적으로 고려한 P factor를 재산정 하였다. P factor를 재산정한 결과 대상 유역 내 밭에 적용된 관리방법과 경운방법, 재배작물의 차이로 인해 상이한 값이 산정되었다. 또한 기존 P factor와 재산정된 P factor를 사용하여 산정한 토양유실량의 차이가 약 17%정도 나타났다. 따라서 본 연구를 통해 재산정된 P factor는 토양유실에 직간접적으로 관여하는 조건들을 복합적으로 고려한 P factor로써 정확한 토양유실량을 산정하는데 기여할 것으로 판단되며, 본 연구를 바탕으로 전국단위 USLE P factor를 산정을 위한 추가적인 연구가 필요하다고 판단된다.

  • PDF