• Journal of Korea Water Resources Association
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• v.42 no.11
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• pp.1005-1015
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• 2009

Saltwater intrusion in coastal aquifer was investigated using a laboratory model. Salt-wedge profiles were reproduced in a porous media tank 140 cm long, 70 cm high, and 10 cm wide. The experiments were performed with various conditions of porous media hydraulic conductivity, salinity, and ground surface slope to assess relationships on salt wedge location and inclination. Salt-wedge profiles induced by saltwater intrusion were observed in porous media equilibrium state, and compared with previously derived formulas of the Glover (1959), Henry (1959) and Strack (1976). It was found that salt-wedge shape and formations were affected by the water level ratio ($H_F/H_S$) due to high hydraulic conductivity, saltwater salinity and ground surface slope. High $H_F/H_S$ of porous media having high hydraulic conductivity shifted the saltwater interface toward the saltwater reservoir. Increasing surface slope of the porous media caused the salt-wedge profile inclination to decrease. Saltwater salinity also contributed to the location of saltwater interface, yet the impact was not more significant than hydraulic conductivity.

• Journal of the Speleological Society of Korea
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• no.77
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• pp.31-42
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• 2007

북제주군 협재리 해안가 인근에 소재한 건지굴을 대상으로 화산지역의 용암동굴에서 특이하게 진행되고 있는 응암석회질화(鎔岩石灰質化: lava-calcification)의 위종동(僞鐘洞)에 대하여 동굴내부와 주변상황에 근거한 분석, 고찰을 통하여 석회질화의 원인을 규명하고, 생태와 환경 및 동굴해안접경구와의 상관성을 고찰하고, 주위에 흔히 분포되어있는 스코리아에 대해 분석응용을 하였다. 용암(화산)동굴은 생성이후 퇴화한다. 그러나 용암동굴에서 용암석회질화의 위종동 현상이 발생하면 용암의 기공과 균열부분 또는 용암석간의 공극에 석회질 성분이 침투, 고화, 융합되면서 구조적 보강효과의 발생으로 오히려 건축구조물의 콘크리트 역할과 같이 견고하게 진행되는 특이현상을 갖는다. 이와 같은 진행성 용암석회질화 현상이 북제주군 협재리에 소재한 건지굴에서 진행되고 있음을 최초로 확인하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.586-588
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• 2005

전세계적으로 수자원이 고갈되어 가는 시점에서 해안에 근접한 지하수의 개발은 매우 중요하며, 현재 이와 관한 연구가 활발히 수행되고 있다. 해안 지하수를 개발하고 관리하기 위한 다양한 시뮬레이터가 존재하여, 많은 시뮬레이터들이 복잡하고 난해한 인터페이스로 인하여 시뮬레이션 생산성과 사용율이 낮은 편이다. 본 논문에서는 GUI에 기반한 사용자 편의 중심의 시뮬레이터 전처리부를 개발하였다. 특히 해안 지하수 개발 관리 시뮬레이터의 하나인 SIOP을 대상으로 하여 마우스 입력 중심의 전처리부를 개발하여 시뮬레이션 생산성과 사용 편의성을 증가 시켰다.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.1-6
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• 1984

Soils in Cheju Island, derived mostly from volcanic ashes, were collected for chemical analysis to determine the effect of land utilization pattern on soil chemical characteristics. The coastal area has long been used for intensive farming and some of the mid-mountain region were recently reclaimed for agricultural crop production. The cation exchange capacity and the organic matter in the soils increased in the order of coastal area < mid-mountain belt < upper mountain area, while pH, base saturation, available phosphorus and exchangeable bases decreased with the elevation. Generally, the organic matter, the cation exchange capacity and the exchangeable bases of the Cheju soils were found to be considerably higher than the Korean mainland soils. However, the base saturation and the available phosphorus were far below the mainland average. The ratio of monovalent basic cations to total exchangeable bases showed the highest in the soils of the mountain belts and the lowest in the coastal area soils. These data suggest that a higher soil pH in the coastal area as compared to the mountainous slopes has resulted not from the sea water but from continuous application of alkaline fertilizers and times.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.188-209
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• 2009

Dangsan forests had been established by local residents several hundred years ago. They were disturbed in various ways, but still remain in many villages where dangsan festivals are held every year. Although the remaining Dangsan forests represent korean rural cultural landscapes, their characteristics still remain to be uncovered. The objectives of this study were to understand the three elements, Dangsan tree (Divine tree), shrine and stone tower, and to investigate the culture at inland areas and seashore areas relation to Dangsan forests. Twenty cases of Dangsan forests at inland areas and twenty at seashore areas were investigated. There were nine shrines and six stone towers found out of twenty inland Dangsan forests. Fifteen shrines were found out of twenty seashore Dangsan forests. Stone tower was not found at seashore areas. Fifteen events of dangsan festival were investigated. Dangsan festival appeared to have played an important role to preserve Dangsan forests. Based on the findings of this study, Dangsan forests are, as landscape elements at inland and seashore areas, proved to have a potential for the improvement of cultural and natural landscapes in the country.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.40-42
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• 2018

지구온난화에 따른 연안의 해수면 상승은 해안에 가해지는 파랑에너지의 상승을 유발한다. 이러한 해수면의 상승은 상대적으로 수심이 깊어지는 효과를 초래하고 이는 과거 발생하지 않았던 해안지역의 침식 및 해빈에서의 모래를 유실시킨다. 특히, 국내 연안 225개소의 연안 모니터링 결과 142개소인 62%가 침식우려 이상의 등급으로 나타났다. 일반적으로 연안침식에 대응하는 방법은 호안을 쌓아 보호하게 되는 경성공법으로 외력의 변화에 따라 현장여건에 맞는 호안의 경사, 단면형상 및 재료를 선택하게 된다. 하지만 현상에 대한 불충분한 이해에 근거한 공법 적용으로 제반국가에서 다양한 피해가 발생하고 있으며, 이는 공법신뢰도 향상을 위한 기술개발 및 융합기술 도입의 필요성을 보여준다. 본 연구는 파랑저감에 효과적인 다공성 구조물Biocoast를 활용하여 해안침식피해억제를 위한 친환경 투수 바이오 콘크리트 블록을 개발하였다. 특히, 자연해변 및 호안시설에 대해 자연 및 인위적 외력에 의한 침식과 세굴로부터 연안을 보호하고, 블록의 유닛화를 통해 품질관리 및 공정관리의 효율성을 향상시킬 수 있을 것으로 사료된다.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.769-776
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• 2010

Concrete structures immersed in seawater are exposed to uniform chloride concentration. However, seashore concrete structures are subjected to various airborne chlorides concentration depending on areas, distance from seashore, orientation of structures and wind direction etc. Therefore, structures which is not coming into direct contact with seawater are greatly affected by salt attack and those cases have been reported. This study intends to investigate salt attack by airborne chlorides in terms of the distance from the seashore based on the measurements conducted at 73 spots and 27 areas during 3 years in the Eastern, Western and Southern coasts of South Korea. Results revealed large regional variations of the salinity in coastal regions along with significant seasonal effects caused by seasonal winds. Moreover, the salinity is seen to diminish as the distance from the seashore increases at a rate corresponding to the function $y=ax^{-b}$. These results will be helpful to do the durability design and management of seashore structures.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.1
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• pp.65-75
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• 2002

The changes of sea bottom configuration, which may cause the coastal disasters, have been considered as social problems. It is obvious that the beach deformation is attributable to the sediment transport associated with erosion and siltation in coastal areas such esturies, channel and harbors. The prediction method and countermeasures far them, however, are not on the level of satisfaction, which indicates that make efforts should be made on developing them. Groin was constructed at Hak-Dong gravel beach to embark ship at 1996, as a result region of right of groin, severe erosion of beach is proceeding till now 1999. In this study, based on the field measurements, involved the one-line theory model which was selected for the prediction of shoreline change to prepare coastal protection methods of Hak-Deng gravel beach. Author found that the storaged sediment estimation model by Sonu and Beek(1971) is useful model at the Hak-Dong gravel beach by the use of topographical survey data from September, 1998 to September, 1999.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.481-496
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• 2009

Every coastal area exhibits its own unique landscape owing to the combination of the natural and cultural processes. Coastal barrier islands well show the cultural aspects of American coastal landscapes. Some 47% of barrier island area was occupied by urban and built-up area in New Jersey, while some 5% in Georgia. Tourism-related development is back to in the mid 19C. in N.J. due to the closeness to heavily populated areas such as New York and Philadelphia. Developments without proper understanding the nature of coastal processes caused New Jerseyization, the destruction of the beauty or naturalness. It was mainly due to the lack of growth-control policies and the foresight for the future coast in the processes of legislation. North Carolina's islands experienced an increase of 269% in urbanized acreage between 1956 and 1976. However, N.C. exercised her wisdom to recover the naturalness of the coastal environs: all engineering structures are banned on the beaches. Nine out of 13 barrier islands in Georgia exist in the wilderness condition owing to her unique history. The remaining islands still experienced the least development. After the Civil War most of Georgian islands were owned by rich families and maintained as wilderness. In the 1970s most of the uninhabited islands were sold or donated to research institutes or governmental agencies.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.5-13
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• 2022

Sunbigi tree(Vitex rotundifolia L.f.), which grows wild in the southern part of Korea and along the coast of the West Sea, has a lot of useful value in terms of resource utilization. Since ancient times, it has been used as folk medicine or herbal medicine in the private sector. Although the leaves and stems have a strong scent, the fruit also has a strong scent, so there are some studies on extracting essential oil from the fruit of Sunbigi tree and analyzing the ingredients, but there are few studies on the fragrance component by extracting hydrosol. The reason is that the fruits are hard and it is difficult to identify the active ingredients contained in the general extraction method. Therefore, in this study, the results of analyzing the components contained in the fragrance of hydrosol obtained by extracting hard fruits at high temperature by different extraction methods are as follows. 1. The extraction condition with the highest flavonoid content was 30.57 mg/g with ethanol, followed by hot water extract at 18.26 mg/g and water extract at 9.69 mg/g with the lowest. 2. As a result of distillation extraction from the fruit of Sunbigi tree, the fragrance of hydrosol is 3-Methyl-2-butenoic acid, cyclobutyl ester, Eucalyptol, L-alpha-Terpineol, 1H-Cycloprop[e]azulen-7-ol, decahydro-1 ,1,7-trimethyl-4-methylene-, [1ar-(1a.alpha.,4a.alpha.,7.beta.,7a.beta.,7b.alpha.)] were found to be many.