• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.607-622
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• 2005

This study was carried out in order to evaluate where the soil loss was mainly occurred, .and to verify how riverbed sediments in the tributaries of the Seomjin River were related to their source rocks distributed in Sunchang area. The study area including the Seomjin River with 4 tributaries of Kyeongcheon, Okgwacheon, Changjeong-cheon and Ipcheon was divided into 10 watershed. The RUSLE (Revised Universal Soil Loss Equation) was estimated for all the grids (10 m cells) in the corresponding watershed. The amount of soil loss per unit area was calculated as follows: dry fold (53,140.94 tons/ha/year), orchard (25,063.38 tons/ha/year), paddy field (6,506.7 tons/ha/year) and Idlest (6,074.36 tons/ha/year). The differences of soil loss per unit area appear to be depends on areas described earlier. Soil erosion hazard zones were generally distributed within dry fields. Several thematic maps such as land use maps, topographical maps and soil maps were used as a data to generate the RUSLE factors. The amount of soil loss, computed by using the RUSLE, showed that soil loss mainly occurred at the regions where possible source rocks were distributed along the stream. Based on the this study on soil loss and soil erosion hazard zone together with chondrite-normalized REE patterns that were previously analyzed in same study area, a closed relationship between riverbed sediments and possible source rocks is formed. Especially in the Okgwacheon that are widely distributed by various rocks, chondrite-normalized REE pattern derived from the riverbed sediments, source rock and soil is expected to have a closed relationship with the distribution of soil loss.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.193-198
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• 1972

Twenty seven specimens of deteriolated storage rice were collected all over Korea. Types of deteriolation were classified according to color outlooks, and for 48 grains of each specimen the causative storage microorganisms were isolated and identified. The following results were observed; 1. 27 specimens of deteriolated rice were classified according to color outlooks into 7 types: reddish yellow 1, light reddish yellow 3, light grayish yellow 4, light red 6, dark gray 7, light gray 3, and rice weevil type 3. 2. The most common storage microorganisms group which infected deteriolated Korean rice were Aspergillus glaucus group, especially species of A. amstelodami, A. chevalieri, A. montevidensis, and A. ruber, which were frequently associated with Penicillium, Brevibactereum, and Bacillus. 3. As a specific case sometimes a specimen of deteriolated rice was infected chiefly by one deminant species of microorganism. Five cases were observed: that is, by P. islandicum, P. lanosum, B. lentus, Pseudomonas cohaerans, Brev. lipolyticum. 4. No definite relationship was observed between color outlook types and the deteriolation causing microorganisms. Only the heavily infected rice by Penicillium islandicum expressed discernible reddish yellow color indicative of the infection by this mold. 5. Mycotoxin problem could be noted in one specimen of deteriolated imported rice heavily infected by P. islandicum. Other mycotoxin producing fungi, A. flavus, A. ochraceus, A. fumigatus were also detected, but their growth frequencies were so low that it might not be serious problem.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.594-604
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• 2021

To evaluate the causes of beach erosion in Sinji-Myeongsasimni Beach, external forces, such as tides, tidal currents, and waves, were observed seasonally from March 2019 to March 2020, and the surface sediments were analyzed for this period. In addition, the shoreline positions and beach elevations were regularly surveyed with a VRS GPS and fixed-wing drone. From these field data, the speed of the tidal currents was noted to be insufficient, but the waves were observed to af ect the deformation of the beach. As the beach is open to the southern direction, waves of heights over 1 m were received in the S-SE direction during the spring, summer, and fall seasons. Large waves with heights over 2 m were observed during typhoons in summer and fall. Because of the absence of typhoons for the previous two years from July 2018, the beach area over datum level (DL) as of July 2018 was greater by 30,138m² compared with that of March 2019, and the beach area as of March 2020 decreased by 61,210m² compared with that of March 2019 because of four typhoon attacks after July 2018. The beach volume as of March 2019 decreased by 5.4% compared with that of July 2018 owing to two typhoons, and the beach volume as of September 2019 decreased by 7.3% because of two typhoons during the observation year. However, the volume recovered slightly by about 3% during fall and winter, when there were no high waves. According to the sediment transport vectors by GSTA, the sediments were weakly influxed from small streams located at the center of the beach; the movement vectors were not noticeable at the west beach site, but the westward sediment transport under the water and seaward vectors from the foreshore beach were prominently observed at the east beach site. These patterns of westward sediment vectors could be explained by the angle between the annual mean incident wave direction and beach opening direction. This angle was inclined 24° counterclockwise with the west-east direction. Therefore, the westward wave-induced currents developed strongly during the large-wave seasons. Hence, the sand content is high in the west-side beach but the east-side beach has been eroded seriously, where the pebbles are exposed and sand dune has decreased because of the lack of sand sources except for the soiled dunes. Therefore, it is proposed that efforts for creating new sediment sources, such as beach nourishment and reducing wave heights via submerged breakwaters, be undertaken for the eastside of the beach.

• Journal of Korea Water Resources Association
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• v.47 no.8
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• pp.729-742
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• 2014

This study predicted long-term sediment distribution for 76 years by using RMA-2 which is two-dimensional numerical model and SED2D which is the sediment transport model to quantitatively analyze sediment distribution in the reservoir based on sediment intrusion and efficiently manage the reservoir. For water level-discharge-sediment data required in boundary conditions of the model, real-time data measured by the Korea Water Resources Corporation were used. The sediment input data was calculated using K-DRUM model. Sedimentation depth was compared with results of model by collecting cross-section core in the reservoir during the dry season. As the result of validation, the sediment depth in the reservoir was similar to actually measured value. For prediction of long-term sediment distribution, terrain data measured in 2012 was used as starting crosssection and simulations for 76 years until 2088 were made. As the results of simulations, sediment distributions of 1.63~1.26 m and 1.45~0.007 m were shown in upstream and downstream of Hapcheon Dam, respectively.

• Journal of Life Science
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• v.27 no.3
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• pp.301-309
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• 2017

This study is examined river naturality and vegetative composition of river riparian zones to identify their most important sources of variation. Information on plant species cover and on physical characteristics that occur at upper, medium, and low areas was collected for 30 riparian plots located throughout the Youngjeong River in Korea. The riparian areas of river banks are dominated by mixed sediment and the vegetation is composed of herbs, shrub, and trees. The floristic characterization of riparian at this river during 2015 season was identified with a total of 28 families, 72 genera, 75 species, 13 varieties, 23 associations. The vegetations of low water's edge and flood way at upper region were naturally formed various vegetation communities by natural erosion. Forty plant species were identified around the upper region, where the dominant growth form was mostly trees. The flood way vegetation at middle region was both of natural vegetation and artificial vegetation. Land uses in riparian zones river levee at low region were bush or grassland as natural floodplain. The values of cover-abundance at upper, middle, and low region were total 9.26, 7.24, and 7.56, respectively. Grasses and forbs at the Youngjeong River have similar cover-abundance values. Recent, many riparian areas of this river have been lost or degraded for commercial and industrial developments. Thus, monitoring for biological diversity of plant species of this river is necessary for an adaptive management approach and the successful implementation of ecosystem management.

• Communications of Mathematical Education
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• v.11
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• pp.259-277
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• 2001

본 연구는 개방형 문제를 활용한 평가가 수학적 창의력에 미치는 효과를 분석함으로써 수학적 창의력을 신장시킬 수 있는 평가 방법을 찾는데 그 목적이 있다. 이를 위해 대구광역시 소재의 C중학교 2학년 1개반과 S중학교 2학년 1개반을 임의로 선정하여 한 반은 개방형 문제를 활용한 평가 집단으로 하고 다른 한 반은 전통적 평가 집단으로 무선 할당하여 실험연구를 실시하였다. 실험처치는 두 집단에게 서로 다른 유형의 평가를 실시하는 것으로, 실험집단은 개방형 문제를 평가과제로 하여 실험집단 담임 교사가 평가를 실시하였으며, 비교집단은 객관식 및 주관식 단답형 문제를 평가과제로 하여 비교집단 담임교사가 전통적인 평가를 실시하였다. 본 연구에서 사용한 검사도구는 수학적 창의력 검사로 사전 사후검사 모두 같은 검사지를 사용하였다. 사후 수학적 창의력 검사의 평균의 차를 t-검정한 결과 유의도p=.025(p < .05)로 실험집단과 비교집단 사이에는 통계적으로 유의미한 차가 있는 것으로 나타났다. 수학적 창의력의 각 요소별로 차이가 있는지 알아보기 위해 사후 창의력 검사의 각 요소별로 평균의 차를 t-검정한 결과, 유창성과 융통성은 각각 유의도 p=.030, p=.040으로 p < .05 수준에서 통계적으로 유의미한 차이가 있었으며, 독창성은 유의도 p=.052로 p < .1 수준에서 통계적으로 유의미한 차이를 보였다. 연구결과 개방형 문제를 활용한 평가가 전통적 평가보다 수학적 창의력 향상에 더 효과적이며, 수학적 창의력의 세 가지 요소(유창성, 융통성, 독창성)의 향상에도 효과적인 것으로 나타났다. 결론적으로 개방형 문제를 활용한 평가가 수학적 창의력 신장에 효과적인 방법임을 시사한다.질공학적 특성의 위도별, 깊이별 변화는 탄산질 퇴적물과 규질 퇴적물의 분포, 수층의 생산성 및 수심변화에 따른 용해도와 퇴적을 차이 그리고 침식 및 재퇴적작용 등 퇴적 과정이 위도별로 달랐기 때문으로 판단된다.haetoceros resting spores/Chaetoceroe vegetative cells도 80 cm 보다 상층에서는 높게 나타나 규조온도지수 분포와도 일치하는 경향을 보인다. 이상의 규조군집 분석 결과에 의하면, 홀로세의 후빙기동안 본 연구 지역인 동해 북동부에는 대마 난류의 유입이후 현재와 유사한 환경이 우세하게 발달했으나, 난류종 P. doliolus의 변화는 동해내에서 대마난류의 세기가 반복되었음을 지시하고 있다./3 수준으로 높다. 결론적으로 풍부한 화학물질들을 함유한 제주해류는 남해 및 동해의 생지화학적 과정들에 있어 상당히 중요함을 시사한다.다. 수조 상층수 중 Cu, Cd, As 농도는 모든 FW, SW수조에서 시간이 지남에 따라 일관성 있게 감소하였고, 제거속도는 Cu가 다른 원소에 비해 빨랐다. 제거속도는 FW 3개 수조 중 FW5&6에서 세 원소 모두 가장 느렸고, SW 3개 수조 중에서는 SW1&2에서 가장 빨랐다. SW와 FW간 제거속도 차이는 세 원소 모두 명확치 않았다 Cr은 FW에서 전반적으로 감소하는 경향을 보였지만 SW에서는 실험 초기에 감소하다 24시간 이후에는 증가 후 일정한 양상을 보였다. Pb은 FW에서 전반적으로 감소했지만 SW에서는 초기에 급격히 증가 후 다시 급격히 감소하는 양상을 보였다 Pb 또한 Cu, Cd, As와 마찬가지로 SW1&2에서 제거속도가 가장 빠르게 나타났다. FW 상층수 중 Hg는 시간에 따라 급격히 감소했고,

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.198-205
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• 2010

The purpose of this study is to investigate the characteristics of the grain size distribution and organic matters to understand the current status of the tidal flat sediment for efficient management of Suncheon Bay. We investigated the characteristics of the surface sediments in the mouth area of the Suncheon Bay at fifteen stations in April and July, 2009. Specific conclusions were as follows. The sediments in the most part of tidal flat was shown as muddy facies(clay and silt contents was more than 90%), whereas in the tidal river affected by water flow from the Dongstream was shown as sandy facies. The analyzed values of the tidal flat sediment were in the range of $1.9{\sim}3.8{\phi}$(mean $2.5{\phi}$) for sorting, and -1.5~3.2(mean -0.3) for skewness, and 1.5~14.1(mean 3.9) for kurtosis. So we knew that the tidal flat sediments in the Suncheon Bay was mainly composed by fine-grained sediment. Erosion was happened in the tidal river, whereas sedimentation was occurred in the tidal flat. The most of organic matters was derived from the Dongstream. Total organic matters shown as ignition loss was 5.75%, COD and $H_2S$ values were lower than the eutrophication level(COD; 20.0 mg/g dry, $H_2S$; 0.2 mg S/g dry). From our research the tidal flat of the Suncheon Bay is relatively fine, but a part of the flat was exceed the environmental standard. So we have to establish effective countermeasures to reduce the organic matters and nutrients derived from stream for environmental preservation of the Suncheon bay and conduct scientifically sustainable monitering for streams flowing into Suncheon Bay and tidal flat.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.66-66
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• 2010

야외지질학습은 교실에서 경험할 수 없는 물질과 현상을 관찰하고 직접 경험할 수 있는 기회를 제공받을 수 있어서 매우 중요하다(Orion 1989). 또한 체험활동으로서 교실에서 학습한 내용의 구체적인 예를 제공하여 교육과정을 촉진시키는데 중요한 요소로 인식되고 있다. 일반적으로 야외 활동은 교실 활동보다 학생들의 경험과 훨씬 더 밀접히 관련되어 있기 때문에 보다 의미가 있을 수 있다. 야외실습 중에서 얻은 경험은 학생들이 그가 관찰한 것에 대해 읽도록 동기화시키고, 교과서와 자연조건에서의 실제적 경험 사이의 차이를 연결해 주는 다리를 제공해 줄 수 있다(홍정수, 장남기, 1997). 야외학습을 위한 적절한 장소는 먼저 학습주제나 목표와 부합되는 곳이어야 하며, 지리적으로 가깝고 안전한 곳이어야 한다(김찬종, 2008). 그렇기 때문에 각 지역별로 학습주제와 부합된 지역을 선정하여 야외지질 학습자료를 개발하는 것은 무엇보다 중요하다. 따라서, 본 연구에서는 전북 남원 일대를 중심으로 한 야외지질 학습자료를 개발하는데 그 목적이 있다. 전북 남원지역은 한반도의 중요지괴에 해당하는 영남육괴 지리산지구에 해당하며 편마암 복합체를 기저로 이를 관입하는 수 차례의 화성활동과 지구조운동으로 복잡한 지질양상을 보인다. 또한 지리산 지역은 평안분지와 경상분지의 일부가 보존되어 있고 지질시대를 달리하는 각종 화성암류가 골고루 분포하여 각 지질시대별로 화성활동과 지구조 운동이 활발했음을 시사해준다. 본 연구에서는 남원 지역의 지질학적 특징을 관찰하기 용이한 지역을 대상으로 총 5곳을 선정하였다. 남원 시내에 소재한 춘향대교 아래 지역은 중생대 쥐라기에 관입한 저반상의 남원화강암과 페그마타이트가 다수 분포하는 곳이다. 이 지역에서는 무수히 많은 관입암체를 찾을 수 있는데 다수의 지진과 지각변동이 있었음을 알 수 있다. 두 번째 장소는 다양한 바위들을 관찰할 수 있는 구룡계곡 일대이다. 이 장소는 오랜기간 동안 물의 흐름에 의해 풍화와 침식을 받은 다양한 크기의 바위를 관찰하고 구별함으로써 풍화에 따른 원마도의 관계, 바위들의 배치 형태를 통해 고지형 및 고수류의 방향을 유추해 볼 수 있다. 남원에서 장수 방향에 위치한 만행산 주변에는 흑운모편마암에 우세한데, 이 지역에서는 흑운모편마암에 나타나는 변성구조로 볼 때 높은 열과 압력을 받은 광역변성작용을 받는 것으로 판단된다. 또한 관입암체 내에 다양한 맥들이 관입을 해와 이를 통해 관입암체들의 상대연령을 판단해보는 학습자료로 활용될 수 있다. 네 번째 장소는 남원시 인월면 인풍리 소재의 인월 피바위 지역이다. 이 지역에서는 압쇄상 화강암이 주로 관찰되는데 이는 기원암인 반상화강암이 동력변성작용을 받아 생성된 것이다. 다섯 번째 지역은 지리산 내의 뱀사골로 지리산 인근에 분포하는 대표적인 편마암인 반상변정질 편마암을 관찰할 수 있다. 변정이란 변성작용을 받는 동안 형성되는 것으로 변성작용을 받는 동안 생긴 것도 있으나 경우에 따라 생성당시 원래 모암속에 포함되어 있는 반정들도 있다.

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.204-217
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• 2013

This study shows the geomorphological processes of Yuga alluvial fan at Dalseong-gun, Daegu in Korea, based on characteristics of geomorphological surfaces, analysis of geomorphological deposits and OSL age dating. Alluvial fans of this area are classified into three surfaces(YG-F1, YG-F2, YG-F3) and were formed by the depositional processes resulting from the changes in hydraulic geometry of flowing water which was a stream flowing out of mountains debouched on to a plain, not by a sudden decrease in surface gradient of river bed. YG-F3 surface, about 110,000 yr B.P.(MIS 5.4), was formed as Yongri river deposited a lot of debris. This result was due to the process that the deposition took place actively with the upward of base level as the last interglacial period began. Later, the denudation of the river valley and geomorphological surface constantly occurred and the local and seasonal changes were found in precipitation and stream discharge with the beginning of the interstadial of the last glacial stages(MIS 3), leading to YG-F2 formed by debris flow, earth flow, mud flow and stream flow. Then, short-term climate changes and temporal climate events repeatedly caused aggradation and denudation over time and going through these processes, YG-F1 is believed to have been made by earth flow or mudflow during the last glacial maximum(MIS 2).

• 한국지구물리탐사학회:학술대회논문집
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• 2002.09a
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• pp.46-66
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• 2002

High-resolution multichannel seismic data were collected in the coastal area near the Gori nuclear power plant to investigate Quaternary fault pattern and timing. A 12 channel streamer, a sparker, and a portable recorder were used for data acquisition. Because the group interval of the streamer was 6.25 m and the sparker can generate acoustic waves with the frequency content of up to 500 Hz, the data show a significant improvement both in horizontal and vertical resolution. The area surveyed is covered with 30-40 m thick Holocene sediments that constitute the mud belt along the southeastern coast of Korea. The survey area is characterized by the well discriminated Pleistocene and Holocene boundary and shallow gas-charged zones. A number of Quaternary faults were found in the sediment column, that are nearly vertical and extend north-south. The Quaternary faults, arranged at a spacing of a few hundred meters, suggest that they were formed in response to compression, although some of them reveal extensional characteristics. Locally, faults disrupt Incised-channel fills that are interpreted to have formed in the early stage of transgression after the beginning of the Holocene. Seismic sections suggest that shallow gas in the mud belt sediments made its way upward through the fractured fault planes. The tectonism responsible for the opening of the East Sea has not persisted since the late Miocene, but vigorous Quaternary faulting activity in the vicinity of the southeastern Korean Peninsula indicates that tectonic stability has yet to be achieved in this region underlain by the hotter than normal mantle.