• 한국환경과학회지
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• 제28권12호
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• pp.1061-1069
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• 2019

Common reed (Phragmites australis) is widespread in reclaimed land and wetland habitats. Every year, the common reed produces extensive colonies by means of underground rhizomes and ground-surface stolons. From an agricultural point of view, the common reed's large biomass is a good material for supplying organic matter. However, it has not yet been studied in terms of seedling production, transplanting conditions, and decomposition characteristics in reclaimed land. Seeds were harvested from the native common reed in Saemangeum, South Korea, the previous year and stored on an open field. The seeds were sowed in the greenhouse at the beginning of April. Common reed decomposition was studied from June to September, with the use of coarse mesh (5 mm) stem litterbags, on three samping dates and with five replicate packs per sample. These packs were dug in five soil condition (low-salinity topsoil, subsoil, high-salinity topsoil, subsoil, paddy topsoil) to 0.2 m and 0.4 m depth. The highest germination rate of common reed seeds was observed in non-salt solution, but the exhibited germination rate was 70% at 9.38 dS m^-1. The plant height of young reed decreased steadily with increasing salinity, but leaf number did not decrease by 9.38 dS m^-1. The survival rate of the two-year-old reed was 83.3%, which was 35% higher than that of the one-year reed. The transplant success rate was 0% in the no vinyl mulching in the soil, but the first year and second year seedlings survived rates were 63% and 83.3%, respectively, in vinyl mulching. Common reed decomposition rates were faster low salinity than high salinity. All nutrient contents were found to fluctuate significantly with time by soil conditions. We also need to study the growth rate of reed transplanting seedlings by soil moisture contents and the comparison of degradation in common reed tissues.

• 자원환경지질
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• 제35권5호
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• pp.465-478
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• 2002

JERS-1 L-밴드 SAR 위성에서 얻어진 5개의 interferogram을 이용하여 1996년 5월 2일부터 1998년 2월 21일 사이 연안매립지인 녹산 국가산업단지의 공단조성과정에서 발생한 지반침하량을 계산하였다. 약 16 m의 공간해상도를 갖는 레이더 관측결과는 현장측정 자료로부터 관측되기 어려운 세밀한 침하 양상을 잘 반영하였다. 정확도 검증을 위해 2-pass DInSAR로 구한 침하량을 Magnetic Probe Extensometer(측정정밀도:${\pm}$1 mm)를 사용하여 총 42개소에 서 측정된 현장자료와 비교하였다. 5개의 쌍으로부터 추정된 DInSAR침하량과 실측침하량의 평균 상관계수는 0.77 이다. 추정된 DInSAR 침하량 중 0.5 이상의 긴밀도를 갖는 점들만을 이용하여 계산한 경우 상관계수는 0.87이며, RMSE는 1.44 cm로 더욱 좋은 결과를 나타낸다. 또한 추정된 회귀선의 기울기는 1.04로 실측값과 DInSAR 추정값이 기울기 1에 가까운 선형관계를 잘 만족하고 있음을 보여준다. 즉 DInSAR 결과 긴밀도 0.5 이상의 지점을 이용하면 효과적으로 연안매립지의 침하량을 관측할 수 있다. DInSAR를 이용하여 계산된 녹산 국가산업단지에서 발생한 최대 누적침하량은 약 60 cm 정도이며, 연구지역의 북쪽과 남서쪽에서는 약 20 cm 이하의 침하가 관측되었다. 이러한 결과는 자연적인 지표변위 관측뿐만 아니라 지반공학적 응용분야에서도 DInSAR 기술이 매우 중요한 역할을 맡을 수 있음을 보여준다.

• 한국해안·해양공학회논문집
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• 제21권5호
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• pp.371-379
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• 2009

본 논문은 매립지에서 과거의 해안선을 산정하는 방법과 문제에 대하여 논의하였다. 우리나라 해안토지의 미등록 실태는 공유수면 매립 시 복잡한 토지소유권 분쟁을 초래할 수 있다. 과거의 해안선은 지적경계와 달리 해안선 정의에 대한 제도적 미흡과 더불어 해안선 변화의 특성으로 인하여 다양한 위치의 해안선이 제시될 수 있으며, 이는 해안빈지 및 포락지의 면적 산정에 직접적인 영향을 미친다. 안정국가산업단지에 대한 사례연구를 통하여 이러한 문제를 저감할 수 있는 체계적인 해안선 조사 방법을 제시하였다. 해안선 변화가 없는 암반해안을 대상으로 매립 이전에 촬영된 항공사진을 이용하여 조위에 근거하는 해안선을 산정하였다. 이를 지상 지형 측량 성과와 비교한 결과, 항공사진측량에 의한 해안선의 정확도는 신뢰할 만한 수준이었다.

• 한국관개배수논문집
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• 제21권1호
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• pp.1-16
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• 2014

The purpose of this study is to calculate agricultural water demand as considering landuse plan of the farm land on the Saemangeum tidal land reclamation project. This study based on the farm landuse plan(2012) and considered some items which did not included previous work like prevention water for resalinization for paddy and upland and muli-purpose water for upland. This study showed that the agricultural water demand estimated $145.123Mm^3/yr$, which is needed as much $14.792Mm^3/yr$ as more water than previous work. The difference comes from the change of unit water demand. Water demand is possible to be changed if guidelines are improved and detailed design work is completed through further study. Especially, the more studies for prevention water for resalinization in a tidal reclaimed farmland and water demand for a horticulture are needed.

• 한국농공학회지
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• 제28권2호
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• pp.53-62
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• 1986

An Idea of Standard Rural Area(SRA), the rural areas which have higher ruralities of the rice cropping region and also higher urban characteristics, was conceptualized to develop the tentative basic indices necessary for rural settlement design in reclaimed land. The SRA's were determined by a technique of the principal component analysis with relevant data from 81 counties or cities located in the west side of Korea(Chon-Nam,Chon-Buk, Chung-Nam, Kyung-Ki Do).By the definition of the SRA, the principal component analysis is seperately carried out by two subworks, analyses of rurality and urban characteristics. From the analysis, rurality of the SRA is characterized by four components which appears to describe the scale of farm management, intensive farming, soundness of farming and farming basis on rice cropping, while urban characteristics of the SRA by three components to describe the accessibility, keeping ratio of infrastructures and level of medical services. Through grouping and synthesizing two characteristics of all counties by each component score, 24 counties were classified as urban-rural harmonized region which is the same result as that obtained from the extraction index being more than 50% of available area to total area except 1 county. Therefore, SRA is defined as the group of counties having more than 50% of available area to total area.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.667-675
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• 2008

As a large construction such as highway, dam, reclaimed land etc. increase in number more and more, large amount of fill materials are required. However, it's difficult to obtain it because of environmental problems and economical efficiency. A alternative plan is to utilize a gypsum which is a by-product yielded from chemical plants and verify suitability to use gypsum as fill materials. Therefore, a characteristic of compaction for gypsum is analyzed and construction methods are given regard to this characteristic from construction of dike using gypsum. Based on the results obtained, it is found that moisture of gypsum in compaction should to be more dry side of O.M.C(optimal moisture content) because of sponge phenomenon. When gypsum is used to fill materials, standards of compaction should be decided from laboratory test.

• 한국농공학회논문집
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• 제58권2호
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• pp.45-52
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• 2016

The object of this paper was to evaulate modified proposed design equation in model test result in order to estimate uplift-resistance of timber pile of reclaimed land greenhouse foundation. Uplift resistance result of model test was increased to according to increased of contact area. Uplift-resistance result of field test tend to lineary increased to according to increased of embedment depth and contact area. Results of field uplift-resistance was evaluate compare with modified proposed design equation results of model test and Effective stress method. As the Effective stress method tend to underestimate, modified proposed design equation results of model test tend to similar type. As the contact area increase, difference between field uplift-resistance results and modified proposed design equation results of model test was considered uplift-speed.

• 한국농공학회논문집
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• 제56권6호
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• pp.139-147
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• 2014

Forecasting salinity in an estuary reservoir is essential to promise irrigation water for the reclaimed land. The objective of the research was to assess salinity balance and its temporal and spatial variations in the Iwon estuary reservoir which has been issued by its high contents of salinity in spite of desalination process for four years. Seepage flows through the see dikes which could be one of possible reason of high salinity level of the reservoir was calculated based on the salinity balance in the reservoir, and used as input data for salinity modeling. A three-dimensional hydrodynamic model, Environmental Fluid Dynamics Code (EFDC), was used to simulate salinity level in the reservoir. The model was calibrated and validated based on weekly or biweekly observed salinity data from 2006 to 2010 in four different locations in the reservoir. The values of $R^2$, RMSE and RMAE between simulated and observed salinity were calculated as 0.70, 2.16 dS/m, and 1.72 dS/m for calibration period, and 0.89, 1.15 dS/m, and 0.89 dS/m for validation period, respectively, showing that simulation results was generally consistent with the observation data.

• 한국초지조사료학회지
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• 제11권1호
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• pp.22-29
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• 1991

This study was experimented to obtain the basic information on the changeable aspect and improvement of soil fertility in newly-reclaimed sloped land. Silage corn was cultivated under the six different treatments for 4 years. The relation between the amount or ratio of annual changes of soil physico-chemical properties and yield of silage corn were analyzed. Soil bulk density was decreased in 3rd year at topsoil, but that decreased in 4th year at subsoil. Soil organic matter also decreased in 2nd year at topsoil, and decreased continuously at subsoil. Bulk density and hardness of soil depths showed significant negative simple correlation with dry matter yield and cation exchange capacity showed positive. Correlation coefficient of chemical properties with dry matter yield were low. The range of annual changes of moisture percent, hardness and organic matter were wider than the other properties. The significantly different of physical properties were higher than the chemical properties, and those of topsoil were higher than subsoil. According to multiple regression between yield and physico-chemical properties of subsoil, bulk density and cation exchange capacity were in the greatest contribution at the variations, but bulk density was greatest at the ratios.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.640-648
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• 2009

Recently the truction of coastal reclaimation work has been extensively implemented in Korea. The Sondo New City is being established on the reclaimed land from the sea, construction companies of metro construction are planing to pull-out the sheet pile for saving the construction cost. In the case of soft marine clay, it is very difficult to pull-out the sheet pile by using the hydraulic hammer difficult. Therefore, the man of the field must be aware of vibration effect to the ground and the structure. For understanding the vibration effect to the ground during subway construction, the model was formulated with 1/25 braced-cut for subway construction. Scott and Iai(1989) proposed the law of the similarity for other experimental conditions. The laboratory model test was conducted under the vibration condition of sheet pile pulling out. The settlement on the ground surface was measured during the shaking table test. The pore water pressure was also monitored in the upper, middle, and lower layers of soil. The field settlement level and the pore water pressure can be predicted by using the results of the laboratory shaking table test.