• Title/Summary/Keyword: peat layer

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Analysis of Correlation Between Wonhyo Tunnel(section of KTX line) Works and Swamp (경부고속철도 천성산구간 원효터널공사와 늪지와의 상관성 분석)

  • Ham, Dong-Sun;Kim, Byeong-Ho;Jeon, Byeong-Gyoo;Kim, In-Soo
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1838-1844
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    • 2007
  • The Wonhyo Tunnel on KTX railroad line is a section of latest concerns from domestic environmental NGOs, which focus on potential destruction of ecosystem or the like due to ever-depleted swamp water at about 300m upward from the tunnel under construction. As a result of study, out of all swamps in the vicinity of the tunnel, it was found that Mujechi 1st and 2nd swamps have been getting smaller in their area little by little since 50 years ago primarily under the influence of eroded streams around lower swamp and even ever-increasing annual mean temperature. As the result of monitoring about swamp before work, it was found that swamp water depends absolutely on amount of rainfall. Besides, the results of monitoring during work also didn't show any leakage generated in the tunnel during and after excavation works with regard to a wheat field swamp in the most vicinity of the tunnel (80m away). On the other hand, it was found that the range affected by ground water sink in tunnel section without grouting process amounted to about 100m around the tunnel, which indicates that such ground water sink has no significant impact upon most of swamps near the tunnel. As the result of testing by two well tracer test around swamps, it was noted that swamp water didn't run out from the bottom of swamp even with adjacent ground water level sunk in factitious ways. And the results of physical survey showed that swamp kept saturated even in dry season when ground water level becomes lower than the bottom of swamp. Therefore, even supposing that ground water level becomes sunk due to tunnel works, it is estimated that the water level of swamps would be still kept owing to impervious layer(peat beds).

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Hydrogeomorphological Characteristics and Landscape Change of Oegogae Wetland in Jirisan National Park (지리산 외고개습지의 수문지형특성과 경관변화)

  • YANG, Heakun;LEE, Haemi;PARK, Kyeong
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.1
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    • pp.29-38
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    • 2010
  • Oegogae wetland is sub-alpine wetland which is formed in piedmont area in Jirisan National Park. Apparently Oegogae wetland seems to be well-protected wetland. Most alpine wetlands are located in the summit area, but Oegogae wetland is located in piedmont area which is transitional zone between the steep slope and relatively flat valley bottom. Oegogae wetland is active in terms of sedimentation and exceeds 1m in depth. Penetration tests show that composing material is soft such as peat and organic-rich sediment. Basal rock of the basin is gneiss and gneissic schist in general, which is good for the formation of wetland because those rocks are easy to form low permeability layer. Baseflow from the wetland takes control of the most of stream flow during the wet season and this is especially true during the dry season. Precipitation during the wet season increases water content and base flow from the wetland.

The Verification Of Green Soil Material Characteristics For Slope Protection (사면 보호를 위한 녹생토 재료 특성 검증)

  • Lee, Byung-Jae;Heo, Hyung-Seok;Noh, Jae-Ho;Jang, Young-Il
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.681-692
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    • 2017
  • In recent years, large-scale construction projects such as road pavement construction and new city construction have been carried out nationwide with by the expansion of social overhead facilities and base on the economic development planning, resulting in a rapid increase in artificial slope damage. The existing vegetation-based re-installation method of the slope surface greening method reveals various problems such as lack of bonding force, drying, and lack of organic matter. In this study, research was carried out using vegetation-based material and environmentally friendly soil additives, were are used in combination with natural humus, Bark compost, coco peat, and vermiculite. Uniaxial compressive strength was measured according to the mixing ratio of soil additives and the strength was analyzed. Experiments were carried out on the characteristics of the soil material to gauge the slope protection properties by using the soil compaction test method wherein the soil and the soil additive materials are mixed in relation to the soil height, the number of compaction, the compaction method (layer) and the curing condition. As a result of the experiment, excellent strength performance was demonstrated in soil additives using gypsum cement, and it satisfied vegetation growth standards by using performance enhancer and pH regulator. It was confirmed that the strength increases with the mixing of soil and soil additive, and the stability of slope protection can be improved.

Effects of Salinity Level and Irrigation Rate on Kentucky Bluegrass (Poa pratensis L.) Growth and Salt Accumulation in Sand Growing Media Established Over the Reclaimed Saline Soil (염해지 토양을 기반으로 조성된 모래 지반구조에서 관수용수의 량 및 염농도에 따른 토양내 염류 집적과 켄터키 블루그래스의 생육에 미치는 영향)

  • Rahayu, Rahayu;Yang, Geun-Mo;Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • v.25 no.1
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    • pp.79-88
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    • 2011
  • The purpose of this study was to obtain information on rates and salinity levels of irrigation for growth of Kentucky bluegrass by minimizing the hazard of salt accumulation in the sand based growing medium. Root zone profile consists of 20 cm sand based top soil, 20 cm of coarse sand as layer to interrupt capillary rise and 10 cm of reclaimed paddy soil as a base of the root zone profile. Topsoil was a mixture of dredged sand and peat with a ratio of 95%: 5% by volume. The columns were soaked into 5 cm depth saline water reservoir with salinity level of 3-5 $dSm^{-1}$. Salinity levels of irrigation water were 0, 2 and 3 $dSm^{-1}$. Irrigation rates were 3.8, 5.7 and 7.6 mm $day^{-1}$ which were equivalent to 70%, 100% and 130% of average ET (evapotranspiration) rate of Kentucky bluegrass, and irrigation interval was 3 days. Salt accumulation was due to irrigated water and moved up water from shallow water base. At the end of second year, the accumulation of salt in the rootzone showed ECc of3.86, 4.7 and 5.1 $dSm^{-1}$, and SAR of 19.2, 23.9 and 27.5 when the salinities were 0, 2 and 3 dS $m^{-1}$, respectively. Irrigation rates of 100% and 130% of ET rate with saline water did not decrease ECe and SAR in growing media. The growth of KEG was influenced by irrigation rate in the $1^{st}$ year, however, salinity level was more critical in the $2^{nd}$ year. Compared to non-saline water, saline water of 2 and 3 dS $m^{-1}$ resulted in decreased visual quality by 3.2% and 16.5%, by 6.4% and 39.3% in clipping weight, and by 5.5% and 5.0% in root mass, respectively.

Studies on the Desalinization and Improvement of Physical-chemical Characteristics of Saline and Alkali Soils by CHP Treatment (CHP에 의(依)한 간척지(干拓地) 토양(土壤)의 제염(除鹽) 및 이화학성질개량(理化學性質改良)에 관(關)한 시험연구(試驗硏究))

  • Lee, S.H.;Oh, J.S.;Im, C.N.
    • Applied Biological Chemistry
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    • v.8
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    • pp.65-73
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    • 1967
  • For the study of method for salt elimination aimed at reforming tidal land into normal paddy fields in a short period with reduction of periods requiring for elimination of saline, CHP (a kind of Ca-hum ate), a soil conditioner made of peat as a main material was tried. In the pot experiment, effect on elimination of salt, improvement of physical-chemical characteristics and rice cultivation test were studied. The results of these tests are as follows: 1, CHP treatment somewhat improves aggregation state with some effect on aggregation. 2. CHP treatment is remarkably effective in permeability which increases with 1.0 percent treatment by three times in percolation rate, and by 4.5 times in volume of leached water respectively. 3. With the increase of CHP amounts, salt was eliminated in short period. When 80% of the total Na was leached in 1.0% CHP-A treated pot, control pot begins permeable. 4. CEC and phosphorous absorption capacity are not influenced by CHP treatment. 5. Growing state of rice is greatly influenced by rainfalls. Growth of rice in tidal land however are almost similar to those in normal paddy fields with layer amounts of CHP treatment. With salt content in the soils, saline hazard and numbers of ineffective stems, amounts of unmatured grain are increased. 6. With the treatment of CHP yields of rough rice were increased. With 0.5% CHP treatment the yields were similar to those of the normal paddy fields. With 1.0% CHP-A treatment, the yields were increased by 15 times more than those of none treated soil and by 25 percent more than normal paddy soils.

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Analysis Actual Conditions of Arid Progress and Prevention Management of Hwaeom Wetland in Yangsansi (양산시 화엄늪의 산지화 진행실태 및 예방관리 방안)

  • Lee, Soo-Dong;Kim, Sun-Hee;Kim, Ji-Seok
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.498-511
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    • 2012
  • Mountainous wetland have many species such as II grade endangered species of wild flora and fauna(Drosera rotundifolia) and environmental indicator species(Utricularia racemosa, Habenaria linearifolia, Parnassia palustris, Molinia japonica, etc.). Accordingly, the mountainous wetlands is very important. However, most mountainous wetlands will disappear by natural or artificial aridness processes. Thus, it needs to manage mountainous wetland for protecting from aridness. This study has found out the wetland status of the environmental ecology and aridness processes moreover, it has suggested ways of improving wetland conservation plan and wetland aridness management plan. According to the results of topography structure survey, Hwaeom wetland's altitude is ranged within 750~810m(87.4%), and slope is less than $10^{\circ}$. There was ideally suited mountainous wetland. However, the water supply(1.6 meters depth and 0.8 meters wide) was built on under the wetland. For that reason, there was concerned about the aridness processes by sweeping away peat layer and dropping the water level. The distribution area of hygrophyte was narrowed to 6.7% whereas, woody plants and xerophytic plants was achieved a dominant position. If it leaves the situation as it is, the mountainous wetland will be developed next succession as forest ecosystem. Therefore, in order to sustain the mountainous wetland from aridness, it is set to the base direction of conservation and management as main schemes. Moreover, we have suggested that setting the vegetation conservation and management area which considering a ecological vegetation characteristics, managing the ecotone vegetation, setting the buffer zone for protection of ecological core areas, protecting the mountainous wetland indicator species and designating the management vegetation. In conclusion, in order to sustain and maintain a soundly wetland ecosystem, it needs to several management of wetlands damage factors. 1) suppression of the excessive groundwater to basin, 2) stabilization of wetland via hydrologic storage, 3) suppression of changing and transforming wetland into forest by succession via management of xerophytic plants.