• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.140-143
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• 2004

The west coast of the Korean Peninsula is famous for its large tidal range (up to 9 m) and vast tidal flats. With comparison the sedimentary environments of open and close tidal flat using remote sensing, we select Kanghwa tidal flat and Hwang-Do tidal flat in Cheonsu Bay. Prior to surface sediment discrimination using remote sensing, sedimentary environments including intertidal OEM, hydraulic condition, and relationship between grain size and various tidal condition are investigated. Remote sensing has the potential to provide synoptic information of intertidal environments. The objectives of this study are: (i) to generate an intertidal digital elevation model (OEM) using the waterline method of Lansat TM/ETM+, (ii) to investigate the tidal channel distribution using texture analysis, and (iii) to analyze the relationship between surface grain size by using in-situ data and intertidal OEM and tidal channel density by using high-resolution satellite data such as IKONOS and Kompsat EOC. The results demonstrate that satellite remote sensing is an efficient and effective tool for a surface sediment discrimination and long term morphologic change estimation in tidal flats.

• 한국물환경학회지
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• 제25권6호
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• pp.935-942
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• 2009

During period of the rainy season of spring tide Aug. 2005, the suspended sediment transport rate from Seomjin River increased ten times as high as neap tide of low river discharge. During ebb tide of high terrestrial input, the grain size of suspended particles of both surface and bottom layer of the water column, showed a uni-modal distribution with a dominant peak at coarse fraction, which suggests a characteristic development of floc-sized particles of low mean effective density. On the contrary, the particles supplied toward upstream of Seomjin river from Gwangyang Bay during flood tide showed a bi-modal distribution with a secondary peak at finer fraction, possibly due to the resuspension and the deflocculation associated with the increased shear velocity at near bottom. Break-up of large flocs is also suggested by the increased mean effective density. However, settling velocity was lower during flood tide because of smaller grain size. Thus, net deposition of suspended sediment is expected at within Gwangyang Bay instead of upstream of Seomjin River, even though suspended sediment transport rate at near bottom water was three times higher than that at surface water during flood tide.

• 한국토양비료학회지
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• 제50권6호
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• pp.684-696
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• 2017

An investigation of grain size, organic compounds and metal distribution in lakes from Geum river basin (Republic of Korea) was conducted in two years (2014 and 2015). The samples of sediment were collected from the 3 lakes (12 sites). The samples were analyzed the concentration of metals (Pb, Zn, Cu, Cr, Ni, As, Cd, Hg, Al, and Li) and general indices including grain size. Spearman correlation coefficients were determined using general indices and metal concentrations respectively. The organic qualities of sediments were improved in 2015 compared with 2014. The concentrations of metals were lower than Sediment Criteria of Lakes in Korea. The significant Spearman correlation coefficients were presented only sand-clay, clay-water content, COD-TOC, Cu-Ni, Cd-Li, Zn-Li, and Cr-Ni of general and metal parameters in 2014, 2015 and both of two years.

• 한국지반환경공학회 논문집
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• 제15권4호
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• pp.13-27
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• 2014

Catchments soil erosion, one of the most serious problems in the mountainous environment of the world, consists of a complex phenomenon involving the detachment of individual soil particles from the soil mass and their transport, storage and overland flow of rainfall, and infiltration. Sediment size distribution during erosion processes appear to depend on many factors such as rainfall characteristics, vegetation cover, hydraulic flow, soil properties and slope. This study involved laboratory flume experiments carried out under simulated rainfall in a 3.0 m long ${\times}$ 0.8 m wide ${\times}$ 0.7 m deep flume, set at $17^{\circ}$ slope. Five experimental cases, consisting of twelve experiments using three different sediments with two different rainfall conditions, are reported. The experiments consisted of detailed observations of particle size distribution of the out-flow sediment. Sediment water mixture out-flow hydrograph and sediment mass out-flow rate over time, moisture profiles at different points within the soil domain, and seepage outflow were also reported. Moisture profiles, seepage outflow, and movement of overland flow were clearly found to be controlled by water retention function and hydraulic function of the soil. The difference of grain size distribution of original soil bed and the out-flow sediment was found to be insignificant in the cases of uniform sediment used experiments. However, in the cases of non-uniform sediment used experiments the outflow sediment was found to be coarser than the original soil domain. The results indicated that the sediment transport mechanism is the combination of particle segregation, suspension/saltation and rolling along the travel distance.

• 한국수산과학회지
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• 제44권6호
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• pp.772-784
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• 2011

We measured grain size, organic matter, and metallic elements (Fe, Cu, Pb, Zn, Cd, Cr, Mn, Hg, and As) in intertidal sediments collected from six islands in the western part of Jellanam Province in order to evaluate heavy metal contamination in the tidal flat sediments of coastal islands. The evaluation of metal contamination was carried out using geochemical assessment techniques such as sediment quality guidelines (SQGs), enrichment factor (EF), and geoaccumulation index ($I_{geo}$). Surface sediments were classified into four sedimentary facies: sand, gravelly muddy sand, slightly gravelly mud, and silt. The concentrations of heavy metals in intertidal sediments from Jaeun, Amtae, Biguem, and Docho islands showed good positive correlations with mean grain size and ignition loss, indicating that the concentrations of metallic elements in these sediments were dependent on grain size and the organic matter content. The concentrations of heavy metals in sediments from almost all of the stations were lower than two criterion values proposed by the National Oceanic and Atmospheric Administration (NOAA) in the United States. Based on the EF and $I_{geo}$ results, surface sediments were a little polluted for Cr and were moderately polluted for As. Our results suggest that more intensive studies are necessary in the future in order to determine the major source of As in intertidal sediment and to evaluate the As pollution level in macrobenthos.

• 한국지형학회지
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• 제17권4호
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• pp.1-16
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• 2010

본 연구는 화강암 유역분지인 내성천과 퇴적암 유역분지인 위천을 대상으로, 하도 지형, 수문, 퇴적물 특성과 하도의 경관 및 지표 피복 특성을 비교·분석하였다. 유역분지의 기반암, 토양, 지표 피복 특성의 차이로 인해, 유속이 느린 위천이 내성천에 비해 하천 수위 변화가 심한 것으로 나타났다. 그리고 입상붕괴된 화강암 퇴적물을 공급 받는 내성천은 상·하류 거의 대부분에서 조립 모래의 입도를 일정하게 나타내고 있지만, 퇴적암 퇴적물이 공급되는 위천은 상류에서 하류로 가면서 평균 입도가 급격히 작아지는 특징을 보인다. 이러한 모래입자 크기의 퇴적물 이동과 준설, 골재 채취 등의 하도 간섭이 활발한 내성천은 위천에 비해 하도 표면의 변화가 심하여 식생 피복이 매우 불량한 것으로 분석되었다.

• 한국수자원학회논문집
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• 제37권5호
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• pp.387-395
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• 2004

본 논문에서는 하상변동 및 유사입자의 시간적 공간적 분포를 동시에 모의할 수 있는 2차원 수치모형을 제시하였다. 사행수로의 하상변동은 만곡부의 외측에서는 하상이 세굴되고 훨씬 더 거친 입경의 재료로 구성되며, 만곡부의 내측에서는 하상이 상승하고, 세립토로 구성되었다. 또한 사행하천에서 흐름의 방향에 대한 입자분포 과정은 상류의 변곡점에서 시작하여, 하류 변곡점에서 마치게 되는 것을 보여주었다. 하천의 경계가 불규칙하고 복잡한 하천에서는 혼합사호 형성된 하천에서보다 균일사로 이루어진 하천에서 하상이 깊게 세굴되는 현상을 보여준다. 혼합사로 이루어진 하천에서의 공간적 입도 분포는 사행하천에서와 마찬가지로 하상이 퇴적되는 사행의 내측에서는 세립토로 구성되고 하상이 세굴되는 외측에서는 굵은 입자로 구성되는 것을 보여주었으며, 하천 폭이 좁은 부분에서는 하상의 세출 및 하상재료가 굵게 변화되는 것을 보여주었다.

• 한국환경과학회지
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• 제27권6호
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• pp.411-423
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• 2018

To investigate the distribution characteristics of grain size and organic matter of surface sediments from the Nakdong-Goryeong Mid-watershed, surface sediments were collected and analyzed. The samples were collected from six sited at four different times between May 2013 and May 2014. The were analyzed for grain size, water content, ignition loss, chemical oxygen demand, total organic carbon and total nitrogen. The surface sediments were mainly composed of medium sand (mean 44.7%) and coarse sand (mean 32.8%) and became coarser in May 2014. Fine sediments at the site NG-2 were poorly sorted and positively skewed, and occur in a tributary environment that is relatively low-energy compared with the other sites. The water content at the studied sites (15.3 ~ 34.9%) averaged 20.25%, and ignition loss (0.4 ~ 5.8%) and total nitrogen (274 ~ 2493 mg/kg) averaged 1.33% and, 696 mg/kg, respectively. These values indicated that the sediments were not seriously contaminated when compared with the sediment pollution evaluation standard of the National Institute of Environmental Research. The chemical oxygen demand (mean 0.17%) was at the non-polluted level compared with United States Environmental Protection Agency sediment quality standards. The total organic carbon (mean 0.18%) at all sites except site NG-2 (lowest effect level) was the no effect level of the Ontario sediment quality guidelines. The COD/IL (0.02 ~ 0.20) and C/N (0.73 ~ 6.76) were less than 1 and 10, respectively. Organic matter in the study area produced naturally from aquatic organisms. Results of principal component analysis showed that fine sediments (very fine sand and silt) were significantly affected by organic matters (ignition loss, chemical oxygen demand, total organic carbon and total nitrogen). In addition, the highest organic matters content in the study area occurred at the site with the finest sediments (NG-2).

• 한국환경과학회지
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• 제26권3호
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• pp.311-324
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• 2017

To certificate change in the geochemical characteristics of surface sediments in the main stream of the Nakdong River, surface sediments from 12 sampling sites during the first and second half year (total 24 sampling sites) were collected and analyzed for grain size, ignition loss, total organic carbon and heavy metal content. Surface sediments mainly composed of sand (coarse and medium sand) and fining changed from the first half to the second half of the year. Ignition loss, total organic carbon and heavy metals content increased in the second half of the year. Some heavy metals (Zn, Ni and Cu) were found to be at the lowest effect levels according to Ontario sediment quality guidelines. Additionally, most heavy metals were found to be at the non polluted level and level I according to USEPA sediment quality standards and National Institute of Environmental Research sediment pollution evaluation standard, respectively. The enrichment factor (< 1) and index of geoaccmulation (< 0) were non polluted in the study area. The correlation analysis results showed that ignition loss, total organic carbon and heavy metal content were highly correlated with grain size. Regarding changes in geochemical characteristics of surface sediments in the study area, grain size fine and organic matter and heavy metal content increased in the second half year. Nonetheless these results indicated pollution levels that did not adversely affect the benthos.

• 한국지구과학회지
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• 제33권4호
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• pp.350-359
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• 2012

30종의 초 중 고 및 대학교 교과서에 나타난 퇴적물의 입도에 대한 한국어 용어를 비교 검토하고 문제점과 대안을 제시하였다. 교과서에 나타난 퇴적물의 입도에 대한 한국어 용어는 거의 모두 Udden-Wentworth의 분류를 번역한 것으로, 교과서마다 다른 용어를 사용하고 있다. 자갈은 여러 교재에서 왕모래, 잔자갈, 왕자갈, 및 표력 또는 거력으로 나타내고 있으나, 이들은 각각 잔자갈(granule), 중자갈(pebble), 큰자갈(cobble), 및 왕자갈(boulder)로 나타내는 것이 적절한 것으로 생각한다. 자갈보다 작은 퇴적물은 '매우 고운', '고운', '중간', '굵은', 및 '매우 굵은'이라는 형용사를 각 퇴적물 이름 앞에 붙여서 표현하는 것이 적합한 것으로 생각된다. silt는 여러 교재에서 미사로 나타내고 있으나 실트로 표현하는 것이 적당하다고 판단된다. 실트와 점토의 혼합물인 mud는 대부분의 초등학교와 중학교, 그리고 일부 고등학교와 대학교 교과서에서 진흙으로 표현하고 있으나 한국지구과학 사전 등을 포함한 여러 교과서에서 쓰고 있는 바와 같이 이토(泥土)로 나타내는 것이 적당하다고 생각한다.