• Ocean and Polar Research
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• v.35 no.1
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• pp.1-14
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• 2013

Shoreline data of the barrier islands in Nakdong River Estuary for the last three decades were assembled using six sets of aerial photographs and seven sets of satellite images. Canny Algorithm was applied to untreated data in order to obtain a wet-dry boundary as a proxy shoreline. Digital Shoreline Analysis System (DSAS 4.0) was used to estimate the rate of shoreline changes in terms of five statistical variables; SCE (Shoreline Change Envelope), NSM (Net Shoreline Movement), EPR(End Point Rate), LRR (Linear Regression Rate), and LMS (Least Median of Squares). The shoreline in Jinwoodo varied differently from one place to another during the last three decades; the west tail has advanced (i.e., seaward or southward), the west part has regressed, the south part has advanced, and the east part has regressed. After the 2000s, the rate of shoreline changes (-2.5~6.7 m/yr) increased and the east advanced. The shoreline in Shinjado shows a counterclockwise movement; the west part has advanced, but the east part has retreated. Since Shinjado was built in its present form, the west part became stable, but the east part has regressed faster. The rate of shoreline changes (-16.0~12.0 m/yr) in Shinjado is greater than that of Jinwoodo. The shoreline in Doyodeung has advanced at a rate of 31.5 m/yr. Since Doyodeung was built in its present form, the south part has regressed at the rate of -18.2 m/yr, but the east and west parts have advanced at the rate of 13.5~14.3 m/yr. Based on Digital Shoreline Analysis, shoreline changes in the barrier islands in the Nakdong River Estuary have varied both temporally and spatially, although the exact reason for the shoreline changes requires more investigation.

• Journal of Korean Port Research
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• v.15 no.1
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• pp.47-56
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• 2001

A numerical model for practical use based on the 1-line theory is presented to simulate shoreline changes due to construction of offshore structures. The shoreline change model calculates the longshore sediment transport rate using breaking waves. Before the shoreline change model execution, a wave model, adopting the modified Boussinesq equation including the breaking parameters and bottom friction term, was used to provide the longshore distribution of the breaking waves. The contents of present model are outlined first. Then to examine the characteristics of this model, the effects of the parameters contained in this model are clarified through the calculations of shoreline changes for simple cases. Finally, as the guides for practical application of this model, several comments are made on the parameters used in the model, such as transport parameter, average beach slope, breaking height variation alongshore, depth of closure, etc. with the presentation of typical examples of 3-dimensional movable bed experimental results for application of this model. Here, beach change behind the offshore structures is represented by the movement of the shoreline position. Analysis gives that the transport parameters should be taken as site specific parameters in terms of time scale for the shoreline change and adjusted to achieve the best agreement between the calculated and the observed near the structures.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.1
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• pp.19-26
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• 1989

The quantification of phenomena presented by the shoreline changes and the prediction of future changes of shoreline are investigated by using a numerical model in this study. Shoreline has been sucessively affected by the activities of reclamation to maximize the land use and it also has been changed with cycles of accumulation and erosion of deposits. Many researches were performed on the jetties constructed to protect facilities adjacent to the shore. However, few studies on a seawall of protecting the beach, being very important in terms of land use, were carried out. Therefore, this study is to analyze effects of a straight seawall to shoreline changes.

• Journal of the Korean Institute of Navigation
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• v.13 no.1
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• pp.77-106
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• 1989

Two numerical models of the shoreline change and sediment transport rates, explicit and implicit, are simulated with shore structures such as breakwaters, a jetty, groins and a seawall. The applied study area is songdo Beach, Youngil bay, Korea since it has all the shore structures mentinoed above. The two models investigate the beach line changes and sedimen transport rates for the beach before design of three groins with and without an offshore breakwater. In order to estimate the shoreline changes after three groins were built, the beach response inside the three groin compartiments and the offshore barrier are also investigated. The simulation based on the initial shoreline conditions surveyed by the Hydrographic office, Koreai 1979 and 1984. The breaking wave characteristics are introduced into the models by calculation from the empirical equations and modification from the numerical and hydraulic model test results developed for waves behind an offshore breakwater. The numerical simulation describes well the tendencies of the sand transport and shoreline changes affected by wave diffraction behind a detached breakwater and by interruption of sand transport at three groins.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.5
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• pp.380-390
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• 2009

This study was conducted as a part of investigating pre-reclamation shorelines from aerial photographs to estimate coastal land area at reclaimed lands (Anjeong industrial complex, Myeongji residental complex, and Noksan industrial complex), southeastern coast of Korea. To assess how the shorelines were suitable for the calculation of coastal lands, we constructed shoreline change data. Secondary ground control points were used to accomplish triangulation for old aerial photographs. Two kinds of shorelines were mapped; one was the shoreline based on approximately highest high water level (AHHWL) and the other was the high water line based on wet/dry signiture. These shorelines were consistent at artificial coast. Shoreline change data were built with a variety of levels of error due to detailed differences in the photograph scale, quality of image, type of ground control point and type of shoreline. Thus assessment of the pre-reclamation shorelines at the level of qualitative analysis for the trend of shoreline changes was satisfactory. Most of shoreline changes before reclamation in this study were associated with coastal development. Investigation of shoreline attributes in relation to aerial photographs allowed us to understand the shoreline changes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.361-374
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• 2007

This study presents long-term shoreline changes of barrier islands in Nakdong Estuary using aerial photographs. Digital photogrammetry is used for constructing mosaic aerial photographs, which yield six sets of shoreline data ranging from 1975 to 2001. Three kinds of rate of shoreline changes such as EPR (End Point Rate), JKR(Jackknife Rate) and LRR (Linear Regression Rate) are computed by a GIS-based Digital Shoreline Analysis Systems. There have been remarkable changes both in Sinja Island and Doyodeung. Western part of Sinja Island advanced seaward, whereas eastern part retreated landward, giving appearance that the island rotated counterclockwise. Rate of shoreline changes at both ends reach 20 m/yr. Doyodeung occurred newly in front of Baekhapdeung in 1993, resulting in shoreline advance in a rate of 40 m/yr. Rate of shoreline changes differ both within and between barrier islands and have a tendency to increase eastward. To understand this spatial variability of rate of shoreline changes, it is suggested to make a detailed investigation into the impact of coastal development on hydrodynamic and sedimentary processes.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.53-59
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• 2010

In this study, an investigation of the shoreline changes at Song-do beach in Busan was carried out for a coastal improvement project to prevent damage from coastal disasters. From the results of the observed data, it is seen that the shoreline moves seaward under extreme wave conditions and moves leeward under normal wave conditions. The reason for this is wave run-up when wave conditions are extreme in summer. In addition, nourishment sand is moved seaward by wave run-up. Thus, the shoreline's slope is gently decreased. Therefore, the shoreline is moved seaward.

• 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.

• Korean Journal of Remote Sensing
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• v.29 no.5
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• pp.477-486
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• 2013

To analyze tendency of temporal and spatial change of shorelines and to estimate rate of shoreline changes using long-term shoreline change data is very important for the coastal environmental management. In this study, investigation was conducted to estimate the rate of shoreline changes using long-term shoreline change data from the year 1985 to 2009 aerial photographs. In this process aerial triangulation, GPS surveying and digital mapping was done for the estimation of changes. As the results, shorelines of Bangpo and Kkotji Beach retreated at a maximum rate of 0.2 m/yr and 0.8 m/yr, respectively. The shoreline could be changed by various factors. However, it was presumed that coastal erosion has been mainly affected by retaining wall constructed in the late 1990s.

• Korean Journal of Remote Sensing
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• v.19 no.2
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• pp.99-106
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• 2003

The shoreline changes were observed and analysed using the video image by a remote unmanned automatic camera monitoring system installed at Haeundae beach of Busan City. In order to analyse quantitatively the shoreline changes caused by waves and tides, the image averaging technique and the rectification technique for obliquely acquired image were applied to the video image during the typhoon Bart in September, 1999. The results showed that the camera monitoring system can be used as a very cost effective and efficient tool for monitoring shorelines which change continuously due to waves and tides.