• Journal of Ocean Engineering and Technology
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• v.17 no.1
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• pp.21-25
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• 2003

해안단애의 형성과 침식에 의한 해안선의 후퇴를 저지하기 위해 방조벽을 설치하여 해빈의 침식 변화과정에 관한 수치모의를 수행하였다. 평균수위의 상승을 동반하는 폭풍해일이 내습하는 경우 평균수위의 상승이 방조벽의 세굴을 가속화시킨다. 그러므로 본 연구는 사빈 해안에 방조벽을 설치하는 경우 해빈 침식의 거동을 예측하는데 이용할 수 있겠다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.179-183
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• 2006

As there are many human activities in the coastal regions, various facilities and coastal engineering structures for protecting beach have been built. Dredging work, reclamation and harbor construction have caused the topography of sea floor to change rapidly. So sedimentation in the vicinity of the groins has get dull and the serious aspects sometimes turn up. Analyzing the surface sediments with transport vector model is one of the good methods to understand the sedimentation in the vicinity of the groins. I analyzed the transport vector of the surface sediments in the vicinity of the groins at the region where serious beach erosion happens near Pohang harbor.

• Journal of The Geomorphological Association of Korea
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• v.23 no.1
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• pp.47-60
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• 2016

In this study, datum points measurement have been collected and then weather data have been analyzed to figure out erosion and deposition environmental change around Halmi-island, Baramarae. First of all, it was difficult to analyze geomorphological change which is caused by climate change because of quite short term of collection period of data. However, differences in spatial distribution of erosion and deposition have locally been shown. In all season, the wind is blowing in north and north-west direction mostly except in summer which is shifted to south direction. However, since its ratio which are above 5m/s is much lower than the north and north-west wind, its effect on geomorphological process is very tiny. In order to look at a tendency of erosion and deposition environmental change around Baramarae Halmi-island, the periphery of Halmi-island was classified to east and west part, then accumulated erosion and deposition values have been calculated. As a result, generally, the datum points are located in the west part which are mostly depositional sites. On the other hand, the datum points are located in east part showed the dominant erosion patterns.

• Journal of the Korean Association of Geographic Information Studies
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• v.4 no.4
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• pp.39-50
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• 2001

There has been considerable controversy over the changes in the size of the beaches in the Pusan area; any loss of beach area will have an immense effect on the tourism industry, which is an important source of income for the local economy. The best beaches in Korea are in the Pusan area and were visited by more than 8 million persons in 2000. It is expected that the number of visitors, drawn to the scenic vistas and convenient facilities of this area, will increase annually. Any loss in the size of these swimming beaches will have an important negative effect on tourism income. Therefore, the local governments have gone to great lengths to preserve these beaches, transporting tens of thousands of tons of sand to the beaches before they open each year at a cost of billions of won annually. In this study, we analyzed aerial photographs and tide data for the past 50 years using digital aerial photo analysis and GIS techniques for each 3-year interval. We abstracted beach DEM (digital elevation model) and ortho aerial photographs, and conducted a space analysis. As a result, we were able to identify changes in the area and width of sections of Haeundae Beach.

• Journal of the Korean earth science society
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• v.36 no.3
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• pp.222-235
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• 2015

Samples were collected from both places including the coastal area within the height of 5 m above the mean sea level (msl) (DH) and the top of the coastal terrace of 10-15 m msl (KS) high in Gwangseungri, Gochanggun, Korea. To find the origin of the deposit in the coastal area, granulometric analysis and geochemical analysis were performed. The result showed that the DH samples were originated from the reddish soils overlaying weathered bedrock which presented gradual change of chemical composition from the bottom toward the top. Clay minerals were found from the DH samples. These results concluded that the DH samples were found as in-situ weathered materials. The KS samples were originated from the soil layer covering gravel layer at the foot slope of the hill along the coast. The KS samples contained different chemical compositions from the DH. It is inferred that some of this layer was disturbed or experienced the influx of foreign material. The particle size of the KS samples was different from those found on the beach. The particle size of lower parts of KS site was finer than that on the beach, but the particle size of middle part of the site was coarser than that on the beach. The sorting of the KS site was poorer than that on the beach. Thus, it is inferred that some parts of the layer were formed by short-lived high energy event rather than sustained and continuous action of tidal currents and/or waves. Analysis using an optically stimulated luminescence (OSL) method showed that the burial age of samples from KS site were found 0.65-0.71 ka. Though the characteristics of the sediment layer and forming event in this area should be further studied, it can be inferred that this sedimentary layer formed by coastal flooding with storm.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.82-92
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• 2006

As beaches throughout Korea have suffered great losses of sand due to artificial developments and meteorological phenomena, particularly typhoons, it is necessary to monitor beaches that are prone to erosion continuously, establish and enforce a comprehensive plan to attack coastal erosion with the object of the long-term management. However, debates and temporary measures, not based on accurate coastal zone surveys and analyses, have been established up to now. Therefore, with Haeundae sand beach as a case study, we proposed methods to collect accurate spatial data of the coastline and the sand beach through GPS survey. And we detected and analyzed topographic changes resulting from Typhoon Nabi quantitatively and qualitatively, by using GIS technique. Results showed a mean elevation of 1.95 m, a total area of 53,441 $m^2$, and a total volume of 104,639 $m^3$ after Typhoon Nabi. Mean elevation rose 0.06 m between the pre- and the post-typhoon surveys by a protective shore wall. However, strong winds and north-northeast surges brought by the typhoon caused erosion of the area and the volume, by 3,096 $m^2$ and 2,320 $m^3$. Accurate spatial databases of coastal zones based on integrated GPS GIS techniques and quantitative and qualitative analyses of topographical changes will help Korea develop systematic and effective countermeasures against coastal erosion.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.6
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• pp.408-415
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• 2016

Small fishing ports and coastal structures installed in a relatively low sea water depth disturb the wave induced current and cause the collapse of equilibrium state of sediment transport. These structures creates diffracted waves and matter the concentration of waves to cause the beach erosion. In order to mitigate these eroding problems on the beach, many counter measurements were proposed such as detached breakwater, groin or headland; however, these methods interrupt the aesthetic view of sandy beach due to the exposed structures above the sea level and have difficulty of applying to those beaches with the good scenery. Furthermore, some of these methods create secondary environmental problems after the installations. To eliminate these problems, one of the countermeasures, artificial reefs have been selected and used worldwide to minimize the disturbance of the scenery and secondary effects on the environment. Meanwhile, it is important to set the design elements for installing the artificial reefs such as that of length, opening width, clearing distances from the shoreline and more. Nevertheless, there are no construction manuals or standards for designing the artificial reefs with these important design elements yet. In this study, different conditions of artificial reefs were used with various cases throughout hydraulic model test to precisely analyze the changes of waves and currents to propose the standards of design elements to install the artificial reefs.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.106-118
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• 2013

Monthly variation in species composition of shallow water fish in Cheonsu Bay were determined using samples collected by a beach seine in the shallow water at Namdang beach from April 2010 to March 2011. The species composition were compared to the data obtained in 1885~86 and in 1993, and factors affecting the long-term change in species composition were analyzed. Fish collected during the study were 25 species, 2,194 individuals and 16,762 g. Chelon haematocheilus were predominated in abundance, accounting 68.5% in the number of individuals. A few number of fish were collected during the cold months from November to April. Abundance was high from July to September by a large catch of juveniles of pelagic fish. Species composition in 1993 did not differ significantly from that in 1985~86 although Fabonigobius gymnauchen living in the fine sediments were increased in abundance. Abundance increase of this gobiid fish was considered to be related to the sedimentation of fine particles due to weakened water circulation after dike construction. The number of species and catch amount in 2010~11 were significantly decreased comparing to those of the former periods; especially in pelagic fish and benthic fish, but C. haematocheilus were greatly increased in abundance. C. haematocheilus is an estuarine fish being able to survive in relatively poor quality of water. This increase seems to be related to fish larvae from the culture net cages recently installed in the inner bay. Recent decrease in abundance of shallow water fish suggested that water quality has been gradually getting poor and recently attained over a critical level for the nursery function of fish.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.239-247
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• 1997

The numerical experiments using a particle tracking model have been performed for predicting the change of water Quality and shoreline. In present study, comparison of the numerical model results with the analytic solution shows that the point of the mainmum concentration and the distribution pattern is very similar. The reflection effect from the boundary was newly Introduced for making clear the effect of the closed boundary which set limits to application of a particle tracking model. The present model seems to reappear physical phenomenon well. This model shows well qualitative appearance of pollutant diffusion in Kwangan beach. Therefore, this model is regarded as a useful means for predicting diffusion movement of suspended sand, and change of water quality.

• Journal of Industrial Technology
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• v.9
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• pp.3-19
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• 1989

Shoreline have been changed from time immemorial continuously, three-quarters of the population of the world live by the sea. It is not too much to say that all of us who live in Han penisular live by coastal zone because we can reach in the beach within only for hours. In this way effectual use and menagement of coastal zone is very importent problems in side of protection of marine resources as well as land use. But it has problems which change of shoreline have to be surveyed and to be predictived. This study the pattern and characteristics of the East sea coast including investigations of the shoreline changes of the East sea. This report gives a description of the method for implementing the seawall boundary condition in the shoreline change numerical model. Such analytical solutions can provide a simple and economical means to make a quick qualitative evaluation of shoreline response under a wide range of environmental and engineering conditions.