• 동굴
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• 제64호
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• pp.49-59
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• 2004

본 연구지역은 북한강과 남한강, 경안천이 합수하는 지역이다. 1973년 팔당댐의 건설로 거대한 호수가 발달하였다. 이는 유속의 감소와 퇴적, 침수 등의 현상을 가져와 호소변에 습지가 발달하는 요인이 되었다. 습지 수원은 지하수면과 함께 지표수, 강수 모두 영향을 받지만, 무엇보다도 댐의 통제계획하에서 발생하는 호소형 습지임을 알 수 있다.

• 한국환경과학회지
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• 제12권7호
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• pp.783-789
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• 2003

This study was conducted to reuse the rice straw ash as washing agent for oil contaminated soils. The results are summarized as follows. The physical characteristics of rice straw before and after burning were as follows ; In case of burning rice straw 1g, the rice straw ash was generated 0.14g and pH was changed neutrality into alkali(pH 10.9) and specific surface area was increased to five times and particle distribution was corresponded to fine silt.(under 0.05mm) The physical characteristics of rice straw ash were Carbon 10.9%, Hydrogen 1.5%, Oxygen 23.4%, Nitrogen 5.2%, Sulfate 1.2% and chemical characteristics were Si 189.2ppm, Ca 10.2ppm, Mg 4.7ppm. Oil cleanup ratio by pH variation were about 40∼50% of initial concentration of oil by pH 10∼11. As the result of cleanup comparative experiment, the rice straw ash was about 20∼30%, the tritonX-100 about 40∼50% of washing efficiency, and then in the future it will be possibility of substitute washing agent.

• 한국습지학회지
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• 제2권1호
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• pp.69-85
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• 2000

Wetlands are generally thought to be among the most fertile and productive ecosystems of the world. They provide a variety of ecological functions to the landscape. In recent years there has been considerable research activity to generate more scientific documentation on the ecological functions of wetlands. Many pollutants released to the environment settle and accumulate in the silt and mud called sediment on the bottoms of wetlands. Contaminated sediment can cause adverse effects to aquatic organism and eventually to ecological system. Sediment toxicity test with water fleas has been done by standardized preparation method of pore and elutriate water methods described in the literature for the need to protect Woopo wetlands. The results of Daphnia magna, Ceridaphnia dubla and Simocephalus sp. toxicity test were compared and discussed in terms of the relative sensitivity and discrimination abilities with both pore and elutriate water obtained from the sediments of Woopo wetlands.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.221-224
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• 2005

Hyperspectral image data have great potential to depict more detailed information on biophysical characteristics of surface materials, which are not usually available with multispectral data. This study aims to test the potential of hyperspectral data for classifying five soil classes defined by the vector product interim terrain data (VITD). In this study, we try to classify surface materials of bare soil over the study area in Korea using both hyperspectral and multispectral image data. Training and test samples for classification are selected with using VITD vector map. The spectral angle mapper (SAM) method is applied to the EO-I Hyperion data and Landsat ETM+ data, that has been radiometrically corrected and geo-rectified. Higher classification accuracy is obtained with the hyperspectral data for classifying five soil classes of gravel, evaporites, inorganic silt and sand.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.379-391
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• 2010

In order to understand the mechanism of cementation of soft soils treated with bacteria, three types of specimens(untreated, normal bacteria concentration treated, and high bacteria concentration treated) were made. Scanning Electron Microscope(SEM), EDX and X-ray diffraction(XRD) analyses were performed on the soft silt and loose sand specimens. Compared with the untreated specimen, a clearer cementation between particles was observed in the high bacteria concentration treated specimen. Based on the scanning electron microscope(SEM) EDX analyses, more calcium carbonate was observed in the specimen treated with high bacteria concentration than other specimens. On the basis of the preliminary results, it appears that microbial cementation can occur in the soft soil. Further study on the cementation of soils using bacteria is necessary to validate this result.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.736-744
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• 2003

This study is conducted to investigate aerodynamic forces and wake structures about the pressure interference of a circular cylinder with slits. An experimental investigation of a circular cylinder with slits is carried out in uniform flow in the range of Reynolds number from 8,000 to 32,000 using X-type hot wire. Flow visualization is executed by smoke-wire method to understand the mechanism of these vortex formation process. Inspection in the wake at X/D=5.5 of the cylinder with the slits suggested that a strong vortex-shedding pattern for these cylinders is revealed compare with a circular cylinder without slits. It is found that the rolling up position of shear layer of the cylinder with slits is shorten compare with a circular cylinder without slits.

• Journal of the korean society of oceanography
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• 제39권1호
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• pp.107-118
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• 2004

A series of mesocosm experiments has been conducted to investigate the effects of sediment on the qualities of superficial water over the tidal flats. The experiments involved two different kinds of sediments (Silt and Fine Sand) to mimic the natural habitats. Other environmental conditions in the mesocosm were kept as natural as possible. The mesocosm coincided with the annual patterns of the natural water qualities and was identical with the composition of benthic organisms of three reference sites of natural tidal flats. DIP has been leached out from sediment from June to October, but not for ammonium and DIN. The mesocosm was successfully able to simulate the environmental situations of natural tidal flat and will be a useful tool to assess the environmental impacts by human activities.

• 한국제4기학회지
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• 제8권1호
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• pp.33-42
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• 1994

The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 춘계학술대회 논문집
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• pp.188-191
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• 2007

The Han River is divided into North and South Korea by NLL(Northern Limit Line) and its area has been blocked by CCL(Civil Control Line) since the Korean War in 1950. Satellite remote sensing, therefore, is uniquely suited to monitoring bar transformation in the region. In river with bar, the characteristics of its physical conditions have a close relationship with bar morphology. In this paper, a monitoring approach of bar transformation in the Han River Estuary is presented using RADARSAT/SAR images from 2000 to 2005 and spatial patterns of bar morphology are presented. it could be said that in the estuary vegetated area and natural levees are developed well, but bars are shifted after an event like a flood. It is also showed that suspended solids such as silt transported through the estuary could contribute highly to a sedimentation environment around Incheon.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.318-326
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• 2008

Recently, a new seismic probe, called "MudFork", has been developed and can be utilized for accurate and easy measurements of shear wave velocities of soft soils. To expand its use to estimate undrained shear strength and density, correlations between those and shear wave velocity were being attempted. Cone penetration tests and a seismic test, using MudFork, were performed at a soft ground site near Incheon, Korea. Also, undisturbed samples were obtained and shear wave velocities of the samples were measured as well as undrained shear strength, using triaxial compression test and bender elements. A simple linear relationship between shear strength and shear wave velocity was obtained, and a tentative relationship between density and shear wave velocity was also defined.