• Journal of the Korean Geographical Society
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• 제43권4호
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• pp.477-494
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• 2008

Stable isotope analyses on lake or wetland sediments are useful to reconstruct paleoclimate. Organic and inorganic carbonates obtained from lake sediment are isotopically analyzed to get oxygen and carbon isotopic ratios. Oxygen isotope ratios can be used to quantitatively and qualitatively reconstruct paleo-temperature or humidity while carbon isotope ratios be used to reveal environmental changes around the lake or human impacts on the area. Peat mosses in peat bogs are nice samples for the carbon isotope analysis, which derives paleo-temperature and paleo-atmospheric $CO_2$ changes. In coastal area, the reconstruction of past sea-level is possible because terrestrial originated organic matter is carbon isotopically different from marine originated organic matter. Also, scientists can do research on Asian Monsoon based on the fact that $\delta^{13}C$ of C3 plants and C4 plants are consistently different each other and that they are distributed differently with respect to salinity. In Korea, paleoenvironmental studies using stable isotopes are not popular yet because of low academic interests on the methodology and difficulties of obtaining proper sediment samples. Interesting results can be produced to answer paleoenvironmental questions of Korea if scientists isotopically analyze sediment cores from a paleo-lake such as Hanon in Jeju island, peat bogs such as Mujechi-Neup and Yong-Neup, and coastal wetlands.

• Journal of the Korean association of regional geographers
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• 제19권4호
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• pp.627-640
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• 2013

Cette $\acute{e}$tude a pour objet d'analyser le processus de morphogen$\grave{e}$se de l'$\hat{I}$le rocheuse de Baek. Nous y voyons une cl$\acute{e}$ pour apprendre son relief marin et le processus de morphogen$\grave{e}$se des l'$\hat{I}$les m$\acute{e}$ridionales de Cor$\acute{e}$e du Sud. Le granit porphorique qui compose l'$\hat{I}$le rocheuse de Baek est une roche magmatique qui s'est form$\acute{e}$e il y a 60 million d'ann$\acute{e}$es. La cause principale de formation de l'$\hat{I}$le rocheuse de Baek, est une ligne de d$\acute{e}$lit vers le NE-SO et l'ENE-OSO, un soul$\grave{e}$vement de la plaque tectonique et une $\acute{e}$rosion par les vagues. L'$\hat{I}$le rocheuse de Baek pr$\acute{e}$sente un caract$\grave{e}$re d'$\acute{e}$ruption de magma de calc-alcalin par analyse g$\acute{e}$ochimique de son granit porphorique et fait partie du granit de l'arc volcanique. Il s'agit d'un magma qui s'est form$\acute{e}$ dans la subduction pr$\grave{e}$s du continent. Il est aussi n$\acute{e}$ssaire d'examiner un soul$\grave{e}$vement qui est plus $\acute{e}$lev$\acute{e}$ qu' un mouvement ascendant de la surface de la mer $\grave{a}$ l'$\grave{e}$re quaternaire environ de l'$\hat{I}$le rocheuse de Baek malgr$\acute{e}$ que, selon nous, nous y trouvions une faille et une terrasse marine.

• 한국지형공간정보학회:학술대회논문집
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• 한국지형공간정보학회 2004년도 추계학술발표대회 논문집
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• pp.167-173
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• 2004

The erosion(or sediment) reaches very serious level due to the aftermath by the imprudent reclamation on the coast. Continuous studies for long on coastline erosion may be warranted and possible countermeasures proposed because the change of the coastline has been progressed slowly for a long period of time in a wide area. Many experts anticipate that the global sea level's average increase by 19-35 cm due to global warming may certainly have an effect on the coastal erosion throughout the world. Thus, a more rigorous study on the causes of changing coastlines is particularly proposed to find ways to counteract any possible threats against coastal environments. In this study, Ortho aerial photo and hydrographic survey datum were utilized to quantitatively analyze coastal erosion and sediment patterns. This paper also seeks to prove that a parcel under the sea occurred due to relatively significant changes to the coastline. We created Ortho aerial photo using aerial photos taken each decade ('81, '93, '00), overlaid them onto a cadastral registration map, and calculated each amount of erosion and sediment while accounting for the tide level and without considering it. As the result of this study, we could propose that the methods of Ortho aerial photo and the marine observation datum were the effective ways of change detection in erosion, sediment, and artificial reclamation of the coastline for a long time.

• Journal of Korean Society for Geospatial Information Science
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• 제17권3호
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• pp.23-31
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• 2009

The border of the shorelines in a nation is an important factor in determining the border of a national territory, but Korea's shorelines are rapidly changing due to the recent rise in sea level from global warming and growth-centered economic policy over the decades of years. This research was done centering on the areas having well-preserved shorelines as they naturally are and other areas having damaged shorelines in their vicinities due to artificial structures at the two beaches located at the neighboring areas and having mutually homogeneous ocean conditions with each other. First, this research derived the shorelines using the aerial photographies taken from 1947 until 2007 and revised the tidal levels sounding data obtained from a hydrographical survey automation system consisting of Echosounder[Echotrac 3100] and Differential Global Positioning System[Beacon]by using topographical data and ships on land obtained by applying post-processing Kinematic GPS measuring method. In addition, this research evaluated the changes and dimensional variations for the last 60 years by dividing these determined shorelines into 5 sections. As a result, the Haewundae Beach showed a total of 29% decrease rate in dimension as of the year 2007 in comparison with the year 1947 due to a rapid dimensional decline centering on its west areas, while the dimension of the Gwanganri Beach showed an increase in its dimension amounting to a total of 69% due to the decrease in flow velocity by artificial structures built on both ends of the beach-forming accumulation; thus, it was found that there existed a big difference in deposition & accumulation tendency depending on neighboring environment in spite of the homogeneous ocean conditions.

• 전기의세계
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• 제18권1호
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• pp.33-37
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• 1969

한전은 1968년 11월 3일 오전 10시 04분을 기하여 154KV 전계통의 직접접지방식 전환을 단행하였다. 종전의 P.C(소고선륜) 중성점접지방식을 직접접지방식으로 전환한것으로서 전력사상 특기 할 만한 근대화사업이며 다년간을 두고 추진해온 중요과제였다. 전력계통의 확대와 복잡화는 선진국가에서도 실시하고 있는 직접접지방식의 채택을 불가변하게 하였고 또한 1차 AID송배전차관도 이의 채택을 조건부로 승인되었던 것으로서 1968년 이후에 건설되는 송변전기기는 직접접지계에서만 운전할 수 있는 절연Level 650KV급이 도입되어 부산화력발전소 3호기가 준공되는 1968년 10월말까지는 직접접지전환이 반드시 이루어져야 하는 실정에 놓여 있었다. 그런데 직접접지방식의 단점인 인접통신선에 미치는 유도장해를 해결하는 문제가 다년간을 두고 진지하게 검토되어 왔으나 해결이 늦어지고 있었다. 사유는 154KV 계통에 인근된 통신선이라면 체신부, 내무부, 교통부, 국방부등 여러기관의 것이 있는데, 유도장해보안방법과 유도보상비문제에 대하여 전력측(상공부, 한전)과 통신측(상기의 체신부등)의 견해차가 해소되지 않기 때문이었다. 그것이 1968년 5월에 와서 전력.통신쌍방이 범국가적입장에서 제반애로를 무릅쓰고 최소한의 투자로 가능한 범위내의 보안책으로서 우선 Arrester 보안방식을 채택하기로 합의되어 경제장관회의를 거쳐 시공하기에 이른것이다. 이 란을 빌려 이 사업의 필요성과 경위및 통신선유도장해방지를 위한 보안방식내용을 간단히 소개함으로써 앞으로 이 분야의 항구적인 유도대책연구에 다소나마 참고가 된다면 다행으로 생각하겠다.면서 예측강우의 질이 저하되기 시작하였으나 QPM을 합성함으로써 생산한 BQPF는 보다 신뢰성있고 양호한 결과를 얻을 수 있었다. 이러한 결과들은 향후 정량적 분포형강우 예측을 이용한 실시간 홍수유출 예측시 댐운영자는 리드타임(홍수선행시간)을 충분히 확보함으로서 안정적이고 예측 가능한 홍수조절을 하는데 도움을 줄 수 있을 것으로 기대된다. 이와 같이 다양한 단기저수지 유입량의 예측정보 제공으로 다목적댐 저수지 운영모형의 효용성을 제고하여 향후 실제 저수지 유입량 예측에 이용함으로써 저수지 단기운영효율 개선에 기여할 수 있을 것으로 사료된다.다. 이것은 여름철 강수량이 증가하고, 호우발생빈도, 특히 8월의 강수일수가 증가하고 있다는 것과 밀접한 관련이 있다. 여름과 가을에 우리나라에 영향을 미치는 태풍의 수는 뚜렷한 추세를 보이지 않으나, 2002년 루사, 2003년 매미로 인하여 각각 6조원, 4조원 이상의 막대한 피해가 발생하였다. 태풍에 의한 피해액은 GDP 대비 약 0.9%(태풍 루사)로 최근 경제상장률과 비교해 보면, 상당한 비율을 차지한다. 우리나라에 영향을 미치는 태풍은 연근해의 해수면 온도가 높아지면 세기가 강해질 가능성이 높다. 폭설과 한파일수도 평년대비 최근 10년 감소하였고 일최저기온이 영하 $10^{\circ}C$ 이하인 날도 연간 발생일수가 감소하였다. 최근 10년간 우리나라 기후의 변화특성은 기온상승과 더불어 서리종료일이 앞당겨지고 열대야가 증가하고 폭설, 한파, 겨울철 일최저기온 영하 10도 이하인 날의 감소 등이 나타나고, 여름철 재해의 원인인 호우일수는 증가하는 추세이다.

• Journal of the Korean Geographical Society
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• 제46권3호
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• pp.277-290
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• 2011

Changes of the characteristics in summer rainfall in the Republic of Korea by the regime shift and their causes were examined by analyzing long-term observational data. There has been an abrupt increase in rainfall variability since 1998, which was mainly due to the enhanced rainfall during August~September, although the gradual increase was also detected in June~July. In June~July, the enhanced rainfall developed as a band type covering the whole East Asia while in August~September, it is only found over the Republic of Korea with the greatest increase of 130 mm over Seoul and Gyeonggi area. The two intensified anticyclonic anomalies over the north-northwest/east of the Republic of Korea resulted in producing northerlies/southeasterlies, transporting cold/warm-wet air flows, respectively. The center of the convergence zone from the two separate systems located in the Republic of Korea, leading to a favorable condition for the development of the extreme rainfall. The enhanced barotropic anticyclonic anomalies also affected in warming the sea surface temperature anomalies covering from the eastern coast of East Asia to North Pacific Ocean, which in turn leaded to enhance warm air transporting back to the Republic of Korea.

• The Journal of Engineering Geology
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• 제13권4호
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• pp.457-474
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• 2003

This study aims to elucidate characteristics of groundwater level fluctuation at riverbank filtration sites in Daesan-myeon, Changwon City. Groundwater level fluctuation, river water level change and stream-aquifer interaction are very important to estimate optimal discharge rate of the pumping well. Water level contours from February 2003 to October 2003 show normal decreasing trend toward the Nakdong river with the hydraulic gradient of 0.008. However, flow reversion occurs when groundwater is discharged at the pumping wells or rise of the Nakdong river by rainfall. The fluctuation of the Nakdong river ranges 0 - 10 m msl. Autocorrelation analysis was conducted to the groundwater levels measured on the six monitoring wells (DS1, DS2, DS3, DS4, DS6 and DS7). The analyzed waterlevel data can be grouped into three: group 1 (DS1 and DS3) represents strong linearity and long memory effect, group 2 (DS1 and DS6) intermediate linearity and memory, and group 3 (DS4 and DS7) weak linearity and memory. Waterlevels of group 1 wells are relatively closely related to the change of river-water level. Those of group 2 wells are largely affected by the pumping and the river-water level, and those of group 3 wells are strongly linked to pumping.

• Journal of Korean Society of Coastal and Ocean Engineers
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• 제20권1호
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• pp.128-136
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• 2008

Recently, the unusual climate change is happening from the global warming in the whole world, the Korean peninsula is also no exception. It is predicted by many researchers that, in the near future, the Super-Typhoon of overwhelming power will occur due to rising temperatures on the sea surface around the Korean peninsula. In this study, numerical simulation has been performed with the Super-Typhoons which combined route of Typhoon Maemi with typhoon conditons of Hurricane Katrina (New Oleans in U.S.A, 2005), Typhoon Durian (philippine, 2006) and Typhoon Vera (Ise Bay in Japan, 1959) at Busan and Gyeongnam coastal area which has been badly damaged due to storm surge every year. From the numerical results, it is revealed that the storm surge heights of the Super-Typhoons are higher than that of Maemi, specially the storm surge height in the case of Katrina is about 4 times larger. So, it can be pointed out that the construction of countermeasures against disasters are very important in order to prepare against an attack of the Super-Typhoons.

• Journal of the Korean Society for Marine Environment & Energy
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• 제8권4호
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• pp.203-212
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• 2005

Anthropogenic emissions of greenhouse gases, particularly carbon dioxide($CO_2$) which arises mainly as wastes from the fossil fuel burning processes, are causing global warming. The effects of global warming become increasingly felt all over the world including sea level rise and extreme weather. The more direct consequences of the elevated atmospheric $CO_2$ on the ocean is the acidification of the surface ocean which brings a far reaching adverse impact on the life at sea and probably on the whole ecosystem of the planet. Improvement in energy efficiency and use of alternative energy sources are being made to reduce $CO_2$ emissions. However, a rapid transition to alternatives seems unachievable within a few decades due to the constraints on the associated technology and socio-economic factors in the world, since fossil fuels make up approximately 85% of the world's commercial energy demands. It has now been recognized that capture and geological sequestration of $CO_2$ could significantly reduce its emissions from fossil fuel utilization and therefore provides the means to rapidly achieve large reductions in $CO_2$ emissions(excerpts from London Convention, LC/SG 28, 2005). In Korea, well-developed sedimentary basins are spread over the vast continental shelf and slope regions, whereas, the land is densely populated and limited in area. Consequently, the offshore area is preferred to the land for the sites for geological sequestration. The utilization of the offshore area, however, may be subject to international agreements including London Convention. In this paper, the recent trends in technologies and regulations for $CO_2$ capture and geological sequestration are described to encourage its applications in Korea.

• Korean Journal of Remote Sensing
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• 제14권2호
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• pp.117-128
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• 1998

Topex/Poseidon satellite, launched in Auguest 1992, has provided more 5 years of very good quality data. Efficient improvements, either about instrumental accuracy or about sea level data correction, have been made so that Topex/Poseidon has become presently a wonderful tool for many researchers. The first mission data of 73 cycles, September 1992 - August 1994, was used to our study in order to know characteristics of environmental correction factors in the Amsterdam-Crozet-Kerguelen region of the South Indian Ocean. According to standard procedures as defined under user handbook for sea surface height data processes, then we have chosen cycles 43 as the cycle of reference because this cycle has provided the completed data for measurement points and has presented the exacted position of ground track compared to another cycles. It was computed variations of various factors for correction in ascending ground track 103(Amsterdam-Kerguelen continental plateau) and descending ground track170 (Crozet basin). Here the variations of ionosphere, dry troposphere, humid troposphere, electromagnetic bias, elastic tide and loading tide were generally very smaller as a few of cm, but the variations of oceanic tide(30-35cm) and inverted barometer(15-30cm) were higher than another factors. For the correction of ocean tide, our model(CEFMO: Code d' Elements Finis pour la Maree Oceanique) - This is hydrodynamic model that is very well applicated in all oceanic situations - was used because this model has especially good solution in the coastal and island area as the open sea area. Conclusionally, it should be understood that the variation of ocean free surface is mainly under the influence of tides(>80-90%) in the Amsterdam - Crozet- Kerguelen region of the South Indian Ocean.