• Economic and Environmental Geology
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• v.54 no.6
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• pp.717-731
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• 2021

We analyzed the characteristics of the habitat environment for the Seonam study area in Ulsan, the southern shore of the East Sea using bathymetry and seafloor environment data. The depth of the study area ranges from about 0 m to 23 m. In the west of the study area, the water depth is shallow with a gentle slope, and the water depth becomes deeper with a steep slope in the east. Due to the right-lateral strike-slip faults located in the continental margin of the East Sea, the fracture surfaces of the seabed rocks are mainly in the N-S direction, which is similar to the direction of the strike faults. Three seafloor types (conglomeratic-grained sandy, coasre-graiend sandy, fine-grained sandy) and rocky bottom area have been classified according to the analyses of the bathymerty, seafloor image, and surface sediment data. The rocky bottom areas are mainly distributed around Seaoam and in the northern and southern coastal area. But the intermediate zone between Seonam and coastal area has no rocky bottom. This intermediate area is expected to have active sedimentation as seawater way. The sandy sediments are widely distributed throughout the study area. Underwater images and UAV images show that Cnidarians, Brachiopods, Mollusks are mostly dominant in the shallow habitat and various Nacellidae, Mytilidae live on the intertidal zone around Seonam. Annelida and Arthropod are dominant in the sandy sediments. The distribution of marine organism in the study area might be greatly influenced by the seafloor type, the composition and particle size distribution of the seafloor sediments. The analysis of habitat environment mapping with bathymetry, seafloor data and underwater images is supposed to contribute to the study of the structure and function of marine ecosystem.

• Journal of the Korean Geographical Society
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• v.37 no.4
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• pp.371-384
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• 2002

It is very important to predict the environmental changes in the land-surface as a way of prevention of sustainable nature. This study investigated the difference between the predicted and actual data of Anmyeon-do from 1981 to 2000 through a fuzzy logic operation using multi-spectral image. According to literature survey, maps, and ground truth data, the types of land-use have changed due primarily to shore reclamation or wild land and grassland fostering before the eighties. After the mid-eighties, however, a number of private residents and commercial stores quickly have spreaded throughout beach resorts and quasi-agricultural and forest areas. Moreover, shore and community regions were severely damaged in the nineties with increased farmland, due to the development of tour places and expansion of city area. The predicted result of the environmental changes in the land-surface using the fuzzy logic operation was almost similar to the state of Anmyeon-do obtained through the satellite image. Particularly, the flat lands near the shore was predicted to change slightly. This area is largely under development, thereby raising concerns on the shore environment. Thus, this method is applicable to conducting research on the change in the land-surface.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.276-283
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• 2009

Enrichment in nutrients coming from urban sewage outfalls can lead to eutrophication in coastal areas, which can also change the species composition and community structure of macro algal communities. We investigated the structure of the macro algal community within three rocky shores in order to assess any possible differences in their characteristics. Site 1 was located near Tongyeong city's sewage outfall, Site 2 was located near a public beach area, and Site 3 faced open channel of the Ocean. All three sites were located within the same stretch of the coast, where Site 2 was located between sites 1 and 3. We measured the nutrient concentration in water and the tissue nitrogen content in macro algae samples. Nutrients in the water column surrounding site 1 were high in ammonium ($30.2\pm1.8{\mu}M$), nitrate ($26.2{\pm}0.1{\mu}M$), and phosphate ($2.7{\pm}0.1{\mu}M$) content, and were characterized by low numbers of macroalgal species and species and a low species diversity index. In contrast, site 3 exhibited relatively low nutrient concentration levels and a high number of macroalgal species and a high species diversity index. Comparative analysis showed that the tissue nitrogen content of macroalgae were significantly (P<0.05) affected by the nutrient concentration in the water column. The tissue nitrogen content of green algae within site 1 was higher than the others sites. However, the tissue nitrogen content of brown algae was similar at all three sites. Thus, the tissue nitrogen content of macro algae and the macro algal community structure of intertidal rocky shores were dependent on location and the performance of macroalgal communities was dependent on water quality.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.537-545
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• 2005

Traditionally Jeju island has a mild oceanic climate throughout the year and famous as worldwide resort area bemuse of its pure natural environment and dramatic coastal scenery. But unpredicted coastal erosion problem, mused by variation of environmental conditions from construction of coastal structure and renovation of the existing ports, has raised its head above the water, and is becoming serious these days just like other coastal area in Korea. The phenomena happen here along the seaside of southern part of the island show that severe changes in coastal line from erosion and even witnessed the coastal cliff failure. In advanced countries, coastal engineers and researchers have studied deeply about this kind of problem for a long time. However, as it is not sot active in Korea and lack of research data, there exists difficulties on building protection methods and thoughtless constructions might make it more complicated and fatal to the coastal environment. In this study, we investigated some case studies of other countries and intended to induce and propose some integral protection methods for coastline erosion, considering environmentally sound and water friendly way of development such as artificial reef, floating breakwater, and double cellblock breakwater. Finally, we made analysis on the proposed methods with numerical model test and evaluation on the feasibility of each method.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.95-105
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• 2020

In order to promote efficient coastal management, it is important to continuously monitor the characteristics of the terrain, which are changed by various factors. In this study, time series UAV images were taken of Gyeokpo beach. And the standard deviation of ±11cm(X), ±10cm(Y), and ±15cm(Z) was obtained as a result of comparing with the VRS measurement performance for UAV position accuracy evaluation. Therefore, it was confirmed that the tolerance of the digital map work rule was satisfied. In addition, as a result of monitoring the erosion and sedimentation changes using the DSM(digital surface model) constructed through UAV images, an average of 0.01 m deposition occurred between June 2018 and December 2018, and in December 2018 and June 2019. It was analyzed that 0.03m of erosion occurred. Therefore, 0.02m of erosion occurred between June 2018 and June 2019. From the topographical change analysis results, the area of erosion and sediment height was analyzed, and the area of erosion and sedimentation was widely distributed in the ±0.5m section. If we continuously monitor the topographical changes in the coastal regions by using the 3D terrain modeling results using the time series UAV images presented in this study, we can support the coastal management tasks such as supplement or dredging of sand.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.11-19
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• 2005

Traditionally Jeju island has a mild oceanic climate throughout the year and famous as worldwide resort area bacause of its pure natural environment and dramatic coastal scenery. But unpredicted coastal erosion problem, caused by variation of environmental conditions from construction of coastal structure and renovation of the existing ports, has raised its head above the water, and is becoming serious these days just like other coastal area in Korea. The phenomena happen here along the seaside of southern part of the island show that severe changes in coastal line from erosion and even witnessed the coastal cliff failure. In advanced countries, coastal engineers and researchers have studied deeply about this kind of problem for a long time. However, as it is not sot active in Korea and lack of research data, there exists difficulties on building protection methods and thoughtless constructions might make it more complicated and fatal to the coastal environment. In this study, we investigated some case studies of other countries and intended to induce and propose some integral protection methods for coastline erosion, considering environmentally sound and water friendly way of developement such as artificial reef, floating breakwater, and double cellblock breakwater. Finally, we made analysis on the proposed methods with numerical model test and evaluation on the feasibility of each method.

• Journal of Agricultural Extension & Community Development
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• v.20 no.2
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• pp.535-554
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• 2013

This study was to investigate the characteristics and management condition of the Singeum village's Dangsan forest, and to seek the revitalization of rural village by improving management scheme. The Dangsan forest in Singeum-ri, Goheung-gun was composed of a Dangsan forest and a Bibo forest. The Dangsan forest was designated as natural monument # 362, and named 'Evergreen forest of Bongnae-myeon, Goheung'. The Dangsan forest area has been disturbed by the building of student training center. Even the local resident couldn't enter the forest due to the fence at the forest boundary except for Dangsan ritual which used to be serviced once a year. The Bibo forest was included in a beach area, and disturbed by lack of management. The Dangsan forest did not stay in good condition with various problems, such as wrong naming as a natural monument and misuse. The driving force of the Dangsan forest maintaining the beauty for several hundred years originated from the conservation of the forest with Dangsan ritual by local residents. Today, the Dangsan forest is in danger of being vanished and not regarded any more as a holy place due to inaccessibility for Dangsan ritual. The Dangsan forest in Singeum village needs to enhance its value as a traditional and cultural landscape, and improving the management scheme will contribute to revitalization of the village.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.243-249
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• 2000

Seasonal variation in species composition and abundance of shallow water fish off Yongwon, Jinhae in the southern coast of Korea was determined by the analysis of monthly samples collected by a beach seine from January to December, 1998. Among 54 species identified, the resident species such as Favonigobius gymnauchen, Chaenogobius laevis, Pholis nebulosa and juvenile Hyporhamphus intermedius were predominated in abundance. The temporal species such as Sardinella zunasi, Leiognathus nuchalis and Takifugu niphobles were collected between April and September. Mean abundance (322 individuals/1000 $m^2$ or 806 g/1000 $m^2$) was higher than that in the shallow sand surf zone of Teachon, but lower than that in the shallow mud area of Chonsu Bay in the western coast of Korea. A large number of H. intermedius were collected in cold months between November and January. The dominant resident species began to be collected from february, and the number of species and biomass were increased until July. A small number of temporal species were collected and subsequently the abundance was low from August to October when high abundance was expected as in the other shallow waters by recruitment of a large number of juveniles of temporal species. The low abundance in these warm months seemed to be related to the water quality by weak water circulation in this shallow mud area.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.290-298
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• 2007

The results of this research on the diversity, zonation of vegetation and micro-topography by TWINSPAN classification and DECORANA ordination, executed with Sinduri coastal dunes of Korea, are as follows: The vegetation and micro-topography of coastal dunes formed a noticeably clear zonation structure. The beach in the direction of the coastline saw a lot of appearance of Salsola komarovi and the primary dune was dominated by Elymus mollis. Imperata cylindrica var. koenigii and Carex pumila formed a colony at flat area of the sand hills and Calamagrostis epigeios was widely distributed at the wet slack. The secondary dune was dominated mostly by Ischaemum anthephoroides and Imperata cylindrica var. koenigii, and it showed an aspect of the distribution of Vitex rotundifolia and Rosa rugosa. while the hinterland hillside in the direction of inland was dominated by Robinia pseudo-acacia and Pinus thunbergii. However, Carex kobomugi, known as the pioneer species of the coastline-bound areas at the coastal dune, dominantly occupied the secondary dune of the rear side and continentally-inclined Miscanthus sinensi and Oenothera biennis of naturalized plant were irregularly spread over the whole of the coastal dune, so the stabilization of micro-topography seemed to be uncertain. Particularly, Miscanthus sinensis was predicted to be changed into dominant species of the primary dune, and secondary dune and slack having a commonly high species gathering inclination with the more progress of stabilization of the coastal dune. The expansion of sand hill wetlands and roads located between the primary dune and secondary dune was judged to have an effect on the zonation structure of plant distribution.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.45-56
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• 1999

Seismic refracrion and reflection surveys were conducted along an E-W trending track of 482 m long in Ilwall-dong, Pohang. End-on spread was employed as source-receiver configuration with 2 m for both geophone interval and offset. Seismic data were acquired using 24 channels at every shot fired every 2 m along the track. Refraction data were interpreted using equations for multi-horizontal layers. Reflection data were processed in the sequence of trace edit, gain control, CMP sorting, NMO correction, mute, common offset gathering, and filtering to produce a single fold seismic section. There are two layers in shallow subsurface of the study area. Upper layer has the P-wave velocities ranging from 267 to 566 m/s and is interpreted as a layer of unconsolidated sediments. Lower layer has P-wave velocities of 1096-3108 m/s and is interpreted as weathered rock to hard rock. Most of the lower layer classified as soft rock. Upper layer has lateral variations in both P-wave velocity and thickness. The upper layer in the eastern part of the seismic line is 3-5 m thick and has P-wave velocity of 400 m/s in average. The upper layer in the western part is 8-10 m thick and has P-wave velocity of 340 m/s in average. The eastern part is interpreted as unconsolidated beach sand, while the western part is interpreted as infilled soil to develop a construction site. Three fault systems of high angle are imaged in seismic reflection section. It is interpreted that the area between these fault systems are relatively safe. Large buildings should be located in the safe ground condition of no fault and footings should be designed to be in the basement rock of 3-10 m deep below the surface.