• 한국지형학회지
• /
• 제27권3호
• /
• pp.53-73
• /
• 2020

Morphology and grain size distribution of coastal dunes should be well documented because they are critical to dune's buffering capacity and resilience against storm surges. The nationwide coastal dune survey produced the dataset, including beach-dune topographic profiles and grain size parameters for frontal beaches, foredunes, and inland dunes. This research investigated the dataset to describe geomorphic and textural properties of coastal dunes: foredune slopes, dune heights above approximately highest high water, mean size, and sorting, together with associated variables of coastal setting that influence coastal dunes. It also explores the possibility of a dune type scheme based on gran size trends. The results are as follows. First, the coast in which dunes are developed is the primary control on foredune morphology and sediment texture. Coastal dunes on the east coast were developed more alongshore rather than inland, with gentler slopes on the higher ground and out of coarser sand. The shore aspect contributes to this pattern because the east coast cannot benefit from prevailing northwesterly. Second, grain size trends from beaches through foredunes to inland dunes were little identified. Third, 12 dune types were identified from 69 dunes, showing the indicative capability for the status of beaches and dunes. We confirmed that the dataset could increase our understanding of the overall characteristics of coastal dune morphology and texture, though there is something to be improved, for example, establishing the refined and comprehensive field survey protocol.

• Fisheries and Aquatic Sciences
• /
• 제4권2호
• /
• pp.51-57
• /
• 2001

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in sediment samples from 19 stations in the coastal areas of Korea from February to July 2000. PCDDs and PCDFs were detected in all sediment samples. The concentrations of these con­taminants ranged from 18.2 to 804.0 pg/g dry weight and I-TEQ concentrations varied from 0.1 to 5.5 pg/g dry weight. Examination of homologue groups showed that octachlorinated dibenzo-p-dioxin (OCDD) was predominant congener in Korean coast. This pattern was similar to homologue profiles of marine sediments in which the main source of PCDDs/DFs was derived from the atmospheric deposition of particulate matters generated from various industrial activities. Grain size and total organic carbon (TOC) distribution are one of the important factors governing PCDDs/DFs concentration in this study.

• 환경영향평가
• /
• 제13권5호
• /
• pp.251-262
• /
• 2004

In order to investigate the geochemical characteristics of surface sediments in lower Yeongsan river system, sediment samples from the main stream of Yeongsan river, Gomakwon and Hampyeong streams were collected and analyzed for grain size and metal and organic carbon contents. The sediment types of the streams widely vary from pebble to mud. The metal contents in the sediments are mainly dependent on grain size of the sediments, geology around the streams and organic matter contents from the domestic sewage. Enrichment factor (EF) representing the degree of metal contamination in the sediments are relatively low in the study area. But, high Zn and Pb values seem to be from the study area, partly.

• Journal of the korean society of oceanography
• /
• 제32권3호
• /
• pp.112-119
• /
• 1997

Coastal sediments collected near the Youngkwang Nuclear Power Plant were analysed for major(Al$_2$O$^_3$, Fe$^_2$O$^_3$, MgO, CaO, Na$^_2$O, K$^_2$O, TiO$^_2$, MnO), trace (Ba, Sr, V, Co, Cr, Cu, Ni, Zn, Pb) metal, and P$^_2$O$^_5$ contents. The composition of bulk metals from most stations fits within the range as those in the average crustal and sedimentary rocks, suggesting that the anthropogenic perturbation of these components is insignificant. The abundance and distribution of total contents for the majority of metals in the surface sediment could be explained by the grain size and were associated with mud (<63 ${\mu}$m) contents. However, distributions of Ca, K, Sr and Ba did not have any significant association with the sediment grain size. This may be due to the geochemical coherence among these metals in certain minerals abundant in coarse grained fractions. The distribution of Pb appears to be partly affected by the contribution from aerosol fallout. Using the R'-mode factor analysis, we show that the variance of the metal contents could be explained by four factors which account for 93.7% of the total variance. It appears that texturally controlled and/or sorting factors influenced by fine fraction are the most dominant factors which determine the relative abundance and distribution of metals in the study area.

• 한국농공학회지
• /
• 제44권4호
• /
• pp.62-74
• /
• 2002

The purpose of this study is to find the variation of sedimentation patterns before Saemangeum reclamation. Residual flow before Saemangeum reclamation was calculated diagnostically from the observed water temperature and salinity data in May 1992 by the Marine Development Institute of Kunsan National University and wind data which were obtained from spring 1969 through winter 1977 by the Gunsan Meteorological Observatory. Three dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-Lagrange method. Calculated sedimentation patterns of riverine materials are highly similar to the observed ones. When suspended sediments with the size of soil grain of 60 ${\mu}m$ are injected from the Mangyeong River, their dispersion range of sediment is about 25km for 24 hours after the injection, while about 35km for 72 hours after the injection. When suspended sediments with the size of soil grain of 200 ${\mu}m$ are injected, their dispersion range of sediment is about 18km for 24 hours after the injection, while about 21km for 72 hours after the injection.

• 한국해안·해양공학회논문집
• /
• 제23권4호
• /
• pp.304-312
• /
• 2011

낙동강 하구 신자도에서 2005년 11월과 2006년 5월에 남쪽 해빈의 상부, 중부 및 하부 조간대에 해당하는 3개의 횡단선(upper, middle 및 lower transect)을 따라 67개 정점에서 총 402개의 표층퇴적물을 채취하여 입도 분석을 실시하였다. 신자도 해빈 퇴적물은 단일 모드의 입도로 구성되었고, 2005년에는 $3.0{\phi}$의 최빈값이 우세하였으며, 2006년에는 $2.5{\phi}$의 최빈값이 우세하였다. 이러한 퇴적물의 조립화는 신자도 해빈의 서쪽 지역과 중부 및 하부 정점들에서 더욱 뚜렷하였다. 이 연구에서는 조위에 의해 구분된 횡단선 자료에 근거하여 퇴적물 입도의 시간적인 변화 특성을 규명하는데 초점을 두었다. 이와 같은 목적을 위하여 횡단선간에 평균입도, 분급도 및 왜도와 같은 퇴적물 조직 변수를 비교할 수 있는 통계적 검정법을 이용하였다. 평균입도는 해빈 중부와 하부 정점들에서, 분급도는 해빈 상부와 하부 정점들에서, 왜도는 해빈 전체에서 통계적으로 유의한 시간적인 변화가 나타났다. 또한, 평균입도와 왜도 사이에 역의 상관관계는 2005년에 비하여 2006년에 더욱 뚜렷하였다. 2005년 11월에서 2006년 5월까지 신자도 해빈 퇴적물의 시간적인 변화는 평균입도와 분급도는 감소하였고, 왜도는 증가하였으며, 평균입도와 왜도 사이에 역의 상관관계가 강화되었다.

• 한국제4기학회지
• /
• 제18권2호통권23호
• /
• pp.19-22
• /
• 2004

Seasonal changes of topograpy, sediment grain size and accumulation rate on the Gomso-Bay tidal flat(Fig. 1), west coast of Korea, have studied in order to understand the seasonal accumulation pattern and preservation potential of tidal-flat sediments. Seasonal levelings across the tidal flat show that the landward movement of both intertidal sand shoals and cheiers accelerates during the winter and typhoon period, but it almost stops in summer when mud deposition is instead predominant on the middle to upper tidal flat. Seasonal variations of mean grain size were largest on the upper part of middle tidal flat where summer mud layers were eroded during the winter and typhoon periods(Fig. 2). Measurements of accululation depths from sea floor to basal plate reveal that accumulation rates were seasonally controlled according to the elevation of tidal-flat surface(Table 1) : the upper flat, where the accumulation rate of summer was generally higher than that of winter, was characterized by a continuous deposition throughout the entire year, whereas on the middle flat, sediment accumulations were concentrated in winter realtive to summer, and were intermittently eroded by typhoons. The lower tidal flat were deposited mostly in winter and eroded during summer typhoons. Cancores taken across the tidal flat reveal that sand-mud interlaers resulting from such seasonal changes of energy regime are preserved only in the upper part of the deposits and generally replaced by storm layers downcore(Fig. 3). Based on above results, it is suggested that the storm deposits formed by winter stors and typhoons would consist of the major part of the Gomso-Bay deposits(Fig. 4).

• 한국해양학회지
• /
• 제27권1호
• /
• pp.55-65
• /
• 1992

황해 남동해역에서 채취한 97개 표층퇴적물을 대상으로 그 지화학적 특성을 규명 하기 위하여 철, 망간, 니켈, 구리 및 납의 5가지 금속원소 함량과 아울러 퇴적물의 입도와 탄산염 함량 등이 분석되었다. 분석된 금속원소 중 니켈과 구리는 퇴적물 입도 와 밀접한 상관관계를 나타내어 그 공간적 분포는 입도분포와 유사하게 나타났다. 이 와는 대조적으로 망간과 납의 경우는 입도와의 관련성이 미약하였으며, 전반적으로 한 국 연안에 인접한 시료에서 높은 함량이 나타났다. 한편, R-mode 요인분석 결과도 니 겔과 구리의 함량을 조절하는 요인이 망간이나 납의 함량을 조절하는 요인들과 구별됨 을 보여주었으며, 금속원소의 행동과 분포에 있어 이렇게 상반된 결과가 나타나는 현 상은 퇴적후 속성작용 및 환경오염물질 유입의 영향에 기인한 것으로 해석되었다. 이 에 근거하여 이들 금속원소들의 비가 서로 다른 기원의 세립물질들을 구분하는 특징으 로 이용될 수 있는 가능성이 제시되었다.

• 한국환경과학회지
• /
• 제24권8호
• /
• pp.969-980
• /
• 2015

In order to certificate the distribution and pollution of heavy metal of surface sediments in Nakdong River were collected and analyzed for grain size, water content, ignition loss and heavy metal content. Surface sediments mainly composed of sand(avg. 94.6%) and water content and ignition loss were 20.46%, 1.53% on average. Grain size were relatively fine and organic matter content were relatively high in the Hoichun and Sunakdonggang. Most of heavy metal content(Zn > Cr > Pb > Ni > Cu > Hg) in the Deokcheongang and Sunakdonggang were higher than the other streams. The Igeo were non polluted(less than 0) in all streams and the EF were relatively high in the small stream and PLI were non polluted(less than 1). In addition, organic matter, heavy metal content and pollution were highly correlation with grain size. Surface sediments in study area, heavy metal pollution of the Sunakdonggang were relatively high compared to the other stream but these results were not serious pollution that exceed the sediment pollution evaluation standard of river and lake in Korea and pollution levels adversely affected the majority of benthos were not.

• 한국지형학회지
• /
• 제24권4호
• /
• pp.27-41
• /
• 2017

In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.