• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1527-1539
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• 2022

As coastal erosion of the east coast is accelerating, the need for scientific and quantitative coastal erosion monitoring technology for a wide area increases. The traditional method for observing changes in the coast was precision monitoring based on field surveys, but it can only be applied to a small area. The airborne bathymetric Light Detection And Ranging (LiDAR) system is a technology that enables economical surveying of coastal and seabed topography in a wide area. In particular, it has the advantage of constructing topographical data for the intertidal zone, which is a major area of interest for coastal erosion monitoring. In this study, time series analysis of coastal seabed topography acquired in Aug, 2021 and Mar. 2022 on the littoral cell GW36 in Gangwon was performed using the Seahawk Airborne Bathymetric LiDAR (ABL) system. We quantitatively monitored the topographical changes by measuring the baseline length, shoreline and Digital Terrain Model (DTM) changes. Through this, the effectiveness of the ABL surveying technique was confirmed in coastal erosion monitoring.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.667-678
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• 1997

A primitive equation numerical model driven only by $M_2$ tide is used to examine role of tide in the temperature and velocity fields of Deukryang Bay. The numerical model reproduces several features of the observational temperature fields such that the isotherms tend to be parallel to the coast in the bay, and the colder water exists at the right hand side in the bay. The horizontal temperature and velocity fields in the model are dominantly influenced by bottom topography. The model also shows that the surface colder water in the bay is accompanied by strong-alongshore current during the flood tide. An investigation for baroclinicity in the bay by additional numerical experiment indicates that the baroclinirity in velocity field is very weak. The model, however, did not reproduce a stratification in the observation, implying that the model needs to add other semi-diurnal components such as $S_2,\;O_2\;or\;K_2$ tides to $M_2$ tide.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.2 s.32
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• pp.13-20
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• 2005

Upon the request of balanced development of the country and making inroads into the continent of China the development of the west coast was begun in the late 1980s, which has been being continued till recently under the blueprint of making the western part of the capital region to be the hub of northeastern Asia. As more lively development is expected to continue in the area, there are many occurrences of change in topology and terrain in the west coast. This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using landsat images. The accuracy of the images was examined by comparing them with GCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From the results, it was concluded that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land, and the area of agriculture and downtown increased, the drainage and bare land area decreased by comparing the change of land use.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.59-67
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• 2022

In this study, the monthly airborne chlorides flying into the offshore bridges were investigated depending on the sea level. The target structures were 9 bridges located on the western and southern coast of South Korea. The airborne chlorides were measured at different sea levels on each bridge every month during 1 year. The results showed that the strongest seasonal wind from the northwest in winter expecially have led increase of the airborne chlorides, and its effect was more significant in the western coast than the southern coast. It was also found that the airborne chlorides declined with the increase of sea level. Three types of curves were suggested for analyzing the decrease trend with the sea level, based on the airborne chlorides at the lowest measurement height of main tower. The trend was varied depending on the sea area, and even in the same sea area, the local topographic condition affected the airborne chlorides. It means that the location and local topography should be considered simultaneously for durability management in the framework of the chloride source, and then the influence of the chloride source should be classified, e.g. safe and dangerous. From these results, it is expected that it could be used as baseline data for the evaluation of the deterioration environment in the Detailed guidelines for safety and maintenance of facilities [Performance evaluation]_Bridge.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.1
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• pp.15-25
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• 2009

Donghae city is one of the most representative cement industrial city in Korea. The area is faced with the East Sea to the East and with high montane region of Tae-Back mountain range to the West. Many pollutant sources of air pollution are located near the coast, but the largest point sources of the region are located at the bottom of the mountain area in Donghae city. The local wind is highly affected by local topography and plays an important role in transport and dispersion of contaminants from the pollution sources. This study was designed to evaluate enhancement of MM5 predictions by using Four Dimensional Data Assimilation (FDDA), the SONDE data and the national meteorological station, data only. The alternative meteorological fields predicted with and without FDDA were used to simulate spatial and temporal variations of NOx in combined with Atmospheric Dispersion Models (CALPUFF). For the modeling domain, the alternative meteorological fields with 1.1 km spatial resolution were interpolated to the CALMET with 0.5 km resolution. The vertical layers set to have 35 and 12 layers for MM5 and CALPUFF, respectively. MM5 with the FDDA did not resulted in significant improvement of meteorological field prediction in Donghae region, which is primarily because of complex geography and wind scheme. The result of CALPUFF, however, showed reduction of uncertainty errors by using the interpolation scheme of the actual measurement data.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.262-274
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• 2018

Spider fauna of Demilitarized Zone (DMZ) and adjacent areas in Korea was surveyed in 2001-2003, 2013-2015, and 2017. Total of 34 surveyed areas across 10 provinces were divided into four main regions (east coast, mid-east mountain, midland, and west coast areas) in accordance with administrative districts and topography. Total of 273 species of 145 genera in 32 families were identified from 10,886 collected spiders. In conclusion, the spider fauna in the DMZ is 281 species of 147 genera in 32 families with 162 species of 99 genera in 23 families in the previous reports. This corresponds to about 37.6% of the Korean spiders as of 2015. The species richness among surveyed localities was ranged 45 species to 92 species. The species richness of each taxon is high in Araneidae, Salticidae, Linyphiidae and Theridiidae. Habitat generalists were 22 species and habitat specialists were 69 species. The 143 species were web builders and 130 species were wanderers by the outlined life style. In DMZ spiders, only 7 species, Thymoites ulleungensis, Arcuphantes pennatus, Lycosa coreana, Allagelena koreana, Cybaeus mosanensis and Cybaeus triangulus, Kishidaia coreana, were recognized as Korean endemic. Five species, Scytodes thoracica, T. ulleungensis, Lycosa labialis, Takeoa nishimurai, and Phrynarachne katoi, are rare species with a trend of decreasing density in recent years. Araneus rotundicornis has been discovered for the first time since its first report. This study may be useful in the conservative management and will contribute to knowledge of the distribution and biogeography of DMZ areas in the future.

• Ocean and Polar Research
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• v.36 no.2
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• pp.87-101
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• 2014

Recently, more attention has been paid to the geomorphological changes in the Nakdong River Estuary, because those changes are caused by artificial activities including weirs, reclamation and construction. In order to analyze quantitatively the recent geomorphological variability in the Nakdong River Estuary, we surveyed the depth and elevation of submarine topography near Jinwoodo and Sinjado from March 2007 to February 2012. A statistical method (based on Digital Shoreline Analysis System) and an Empirical Orthogonal Functions method were used to evaluate the morphological changes. According to the statistical variables (DCE, NDC, EPR, LRR), the highest amount and rate of accumulation were recorded around the Gadeokdo whereas the greatest amount of erosion appeared around the coast off the eastern part of Sinjado. In particular, a dynamic variation of morphology was clearly observed in the vicinity of the sub-tidal channel located between Jinwoodo and Sinjado, which seems to be attributable to channel migration. As a result of the EOF method, the first mode (48.7%) is most closely related to the pattern of morphological variability that might be associated with the westerly movement of sediment by longshore current. The spatial variability of the second mode (16.6%) was high in the shoreface of Sinjado, showing a 4-year periodicity of temporal variability. The strong correlation (coefficient 0.73) between the time coefficient and suspended sediment discharge from Nakdong River emphasizes the role of sediment discharge to deposition in this area. The spatial variability of the third mode (11.3%) was distributed mainly around the coast off the eastern part of Sinjado, which is related to the movement of the coastline of Sinjado. Based on the last 5 year's data, our results suggest that the study area is characterized on the whole by a depositional pattern, but the extent of sedimentation is different locally.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.897-904
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• 2006

The eastern coast of northeastern Brazil (NEB), a coastal land-strip up to 300 km wide and stretching out from Rio Grande do Norte $(5^{\circ}S)$ State down to the south of Bahia State $(17^{\circ}S)$, experiences different rain producing systems, such as distrubances in the south-east trade winds, frontal systems penetration, land-sea breeze circulation and local convection associated with the topography and moisture flux convergence. The annual total rainfall ranges from 600 inland to 3000 mm on the coast. Rainfall totals 5 to 12 times the focal climatic means were recorded in various regions of Alagoas state in January 2004. It was estimated that 46,000 people were homeless, with material damages exceeding US$10 million as a consequence of the ensuing floods. GOES infrared images analysis showed that the main weather system responsible for this anomalously high rainfall totals was an Upper Troposphere Cyclonic Vortex (UTCV), which formed at about a $27^{\underline{\circ}}W\;e\;12^{\underline{\circ}}S$ and remained active for the entire month of January over NEB.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.6
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• pp.350-360
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• 2016

In order to investigate characteristics of waves and currents varying in space in the Haeundae coast in winter, numerical simulations by using a 2-D spectral wave model(SWAN) and 2-DH hydrodynamic model(Delft3D) were carried out in this study. The results of numerical simulations were validated with the field data collected at several different locations in the study area in February, 2014. From the numerical simulations, it was found that waves and currents were significantly influenced in terms of direction and magnitude by bottom topography characterized by straggling rock crops covered with sea grasses. The coupling of SWAN and Delft3D models also revealed that alongshore currents directing from the east to the west were developed in the nearshore, due to the influence of larger waves with the main incident direction from the east.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.293-301
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• 2002

MGF(Marine Geographical Framework) data are the essential data sets concerning graphical and attribute information on coast and ocean among various marine-related data, which consist of framework data of the National Spatial Data Infrastructure(NSDI). This study did research and analyzed the development of current data, the situation of its usage, related technical environment and case study of foreign countries through the survey on the users and experts. Then the item of marine geographical framework data was selected in accordance with the measures for usage and management of possible MGF data. A map was pilot producted based on selected items and MGF data was presented through making up some problems shown ill the process. The importance of GIS will be growing continuously which can develop, deal with and provide the various data to efficiently manage coast and ocean. Accordingly, the MGF data will be applied to various areas such as Internet or raw data for marine information system.