• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.693-703
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• 2019

Long-term coastal topographical data is critical for analyzing temporal and spatial changes in shorelines. Especially understanding the change trends is essential for future coastal management. For this research, in the data preparation, we obtained digital aerial images, terrestrial laser scanning data and UAV images in the year of 2009. 2018 and 2019 respectively. Also tidal observation data obtained by the Korea Hydrographic and Oceanographic Agency were used for Bangamoeri beach located in Ansan, Gyeonggi-do. In the process of it, we applied the photogrammetric technique to extract the coastline of 4.40 m from the stereo images of 2009 by stereoscopic viewing. In 2018, digital elevation model was generated by using the raw data obtained from the laser scanner and the corresponding shoreline was semi-automatically extracted. In 2019, a digital elevation model was generated from the drone images to extract the coastline. Finally the change rate of shorelines was calculated using Digital Shoreline Analysis System. Also qualitative analysis was presented.

• Korean Journal of Remote Sensing
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• v.31 no.1
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• pp.29-38
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• 2015

The coastline influenced naturally and artificially changes dynamically. While the long-term change is influenced by the rise in the surface of the sea and the changes in water level of the rivers, the short-term change is influenced by the tide, earthquake and storm. Also, man-made thoughtless development such as construction of embankment and reclaimed land not considering erosion and deformation of coast has been causes for breaking functions of coast and damages on natural environment. In order to manage coastal environment and resources effectively, In this study is intended to analyze and predict erosion in coastal environment and changes in sedimentation quantitatively by detecting changes in coastal line from data collection for satellite images and aerial LiDAR data. The coastal line in 2007 and 2012 was extracted by manufacturing Digital Surface Model (DSM) with Aviation LiDAR materials. For the coastal line in 2009 and 2010, Normalized Difference Vegetation Index (NDVI) method was used to extract the KOMPSAT-2 image selected after considering tide level and wave height. The change rate of the coastal line is varied in line with the forms of the observation target but most of topography shows a tendency of being eroded as time goes by. Compared to the relatively monotonous beach of Taean, the gravel and rock has very complex form. Therefore, there are more errors in extraction of coastlines and the combination of transect and shoreline, which affect overall changes. Thus, we think the correction of the anomalies caused by these properties is required in the future research.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1D
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• pp.81-88
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• 2012

This present research was carried out by dividing two parts; field surveying and data processing, in order to analyze changed patterns of a shoreline. Firstly, the shoreline information measured by the precise GPS positioning during long duration was collected. Secondly, the algorithm for detecting an auto boundary with regards to the changed shoreline with multi-image data was developed. Then, a comparative research was conducted. Haeundae beach which is one of the most famous ones in Korea was selected as a test site. RTK-GPS surveying had been performed overall eight times from September 2005 to September 2009. The filed test by aerial Lidar was conducted twice on December 2006 and March 2009 respectively. As a result estimated from both sensors, there is a slight difference. The average length of shoreline analyzed by RTK-GPS is approximately 1,364.6 m, while one from aerial Lidar is about 1,402.5 m. In this investigation, the specific algorithm for detecting the shoreline detection was developed by Visual C++ MFC (Microsoft Foundation Class). The analysis result estimated by aerial photo and satellite image was 1,391.0 m. The level of reliability was 98.1% for auto boundary detection when it compared with real surveying data.

• The Korean Journal of Quaternary Research
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• v.9 no.1
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• pp.1-18
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• 1995

The intent of this study is to suppose the time of engraving of Bangudae-rockgraving-picture and the change of the ancient soci-ety related to the Postglacial transgression and regression in the Ulsan Bay. Main results can be summed up as follows; 1. It is supposed that the shoreline in the maximum Postglacial transgression of the Ulsan bay has arrived to Gulhwa-Ri about 14km upstream from the present Taehwa River mouth. 2,.This transgression has occurred about 6,000-5,000 years ago. The prehistoric men around the Bangudae had hunted the whale near the inner bay From this time the people had begun to engrave pictures on the Rock of Bangudae for the ceremony and instruction of the whale hunting,. 3. Since then the shoreline had regressed and the whale hunting area had moved to distant area from the residence and the number of the captured whales had diminished. The whale hunting society had been transformed to the overland animals on the Bangudae-rockgraving- pictures had gradually increased.

• Journal of Ocean Engineering and Technology
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• v.23 no.4
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• pp.19-24
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• 2009

In order to analysis the variation in vegetation area caused by topographical change at Jinudo in the Nakdong estuary, we used aerial photographs of Jinudo from 1998 to 2006. To extract an accuracy shoreline from these aerial photographs, a tide calibration was performed. We also estimated the annual variation in topographic area and vegetation area, and then analyzed the relationship between them by a correlation analysis. The following results were obtained: 1) The calibrated shoreline distance of Jinudo from 1998 to 2006 was estimated to have a range of (-)1,927 cm to (+)4,671 cm. 2) Annual changes in the topographic area and vegetation area in Jinudo have been increasing gradually from 1998, and the correlation coefficient between topographic area and vegetation area is 0.97. 3) The estimated topographic areas were with following order: southern (III), eastern (IV), northern (II) and western (I), while for the vegetation area, the order was southern (III), northern (II), eastern (IV) and western (I). 4) The vegetation area of the southern region (III) of Jinudo had the largest size among the regions, and was calculated to be $4.3{\sim}5.4$ times larger than the eastern region (IV).

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.803-813
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• 2021

Coastal erosion has been a threat to coastal communities and emerged as an urgent problem. Among the coastal communities that are under perceived threat, Cotonou located in Benin, West Africa, is considered as one of the most dangerous area due to its high vulnerability. To address this problem, in 2013, the Benin authorities established seven groynes at east of Cotonou port, and two additional intermediate groynes have recently been integrated in April 2018. However, there is no quantitative analysis of groynes so far, so it is hard to know how effective they have been. To analyze effectiveness, we used optical satellite images from different time periods, especially 2004 and 2020, and then compared changes in length, width and area of shoreline in Cotonou. The study area is divided into two sectors based on the location of Cotonou port. The difference of two areas is that Sector 2 has groynes installed while Sector 1 hasn't. As result of this study, shoreline in Sector 1 showed accretion by recovering 1.20 km² of area. In contrast, 3.67 km² of Sector 2 disappeared due to coastal erosion, although it has groynes. This may imply that groynes helped to lessen the rate of average erosion, however, still could not perfectly stop the coastal erosion in the area. Therefore, for the next step, we assume it is recommended to study how to maximize effectiveness of groynes.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2004.08a
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• pp.254-258
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• 2004

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2004.08a
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• pp.259-263
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• 2004

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.4
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• pp.258-267
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• 2004

Coastal and harbor structures, which are constructed for the beach protection and coastal zone development, often cause the severe beach erosion problem resulted from changes of longshore sediment transport. In this study, we present a new methodology to estimate the longshore sediment transport rates using the measured data of beach profiles or shorelines. The methods is applied for the prediction of longshore sediment transport rates along Kailua beach, Hawaii and shorelines in the vicinity of Anmok Harbor, Korea.

• Journal of Environmental Science International
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• v.23 no.2
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• pp.323-330
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• 2014

Transport of bed load and suspended particle in coastal waters is main factor causing change in shoreline, and effective measurement method and appropriate equipment is required. To measure bed load and suspended particle transport an equipment was designed and manufactured, and it was applied in the field. The equipment consists of four main elements, body supporter, bed load and suspended particle sampler, sampler support and lock. Eight samplers were installed along the circumference of each supporter, and each sample is a 45-degree intervals. The field experiment was done once along Gyeongpo beach in August 2013. This note described the design and function of the equipment and results of field experiments.