• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.445-445
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• 2022

최근 새만금 방조제 건설이 완료됨에 따라 주변 연안지역의 지형에 많은 변화가 감지되었다. 본 연구대상지는 격포해수욕장으로서 새만금 사업 준공 후 연안침식에 따른 모래 유실 등으로 인해 양빈사업 등이 검토되고 있는 상황이다. 본 연구에서는 연안지형 변화 탐지를 위한 UAV (Unmanned Aerial Vehicle) 활용기술을 제시하는 것으로서 총 3회에 걸쳐 UAV 영상을 촬영하였다. 영상촬영은 DJI Inspire 2 UAV를 활용하였으며 VRS(Virtual Reference Service) 측량성과와 연계하여 Pix4D Mapper SW를 통해 정사영상과 수치표면모델(DSM; Digital Surface Model)을 제작하였다. 먼저 2018. 6. 29 ~ 2018. 12. 10 사이의 지형변화 탐지를 수행한 결과 침식과 퇴적의 최대값은 각각 2.56m와 2.24m로 나타났으며 평균적으로는 0.01m의 퇴적이 발생하였다. 그리고 2018. 6. 29 ~ 2019. 6. 14 동안의 침식과 퇴적의 최대값은 각각 2.31m와 2.28m로 나타났으며 평균값은 0.02m의 침식이 발생하였다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 침식과 퇴적의 최대값이 각각 2.28m와 2.55m로 나타났으며 평균값은 0.03m의 침식이 발생하였다. 지형변화를 보다 상세히 모니터링하고자 퇴적과 침식구간을 나누어 분석을 수행한 결과, 2018. 6. 29 ~ 2018. 12. 10 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 13,324.4m²와 14,667.3m²로 퇴적구간의 면적이 1,342.9m² 만큼 높게 나타났으며, 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,176.6m²와 11,723.0m²로 침식구간의 면적이 4,453m² 만큼 높게 나타났다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,821.6m²와 11,126.4m²로 침식구간의 면적이 5,695.2m² 만큼 크게 분석되었다. 이와 같이 UAV 영상 기반의 연안지형 모니터링을 수행할 경우 시계열 지형변화를 효과적으로 모니터링할 수 있으며, 이러한 업무는 새만금 방조제 건설에 따른 지형변화의 영향평가 등 다양한 연안업무에 활용될 수 있을 것이다.

• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.197-207
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• 2016

This study aims at providing basic data to objectively evaluate the areas suitable for reintroduction of the species of Asiatic black bear (Ursus thibetanus) in order to effectively preserve the Asiatic black bears in the Korean protection areas including national parks, and for the species restoration success. To this end, this study predicted the potential habitats in East Asia, Southeast Asia and India, where there are the records of Asiatic black bears' appearances using the Maxent model and environmental variables related with climate, topography, road and land use. In addition, this study evaluated the effects of the relevant climate and environmental variables. This study also analyzed inhabitation range area suitable for Asiatic black and geographic change according to future climate change. As for the judgment accuracy of the Maxent model widely utilized for habitat distribution research of wildlife for preservation, AUC value was calculated as 0.893 (sd=0.121). This was useful in predicting Asiatic black bears' potential habitat and evaluate the habitat change characteristics according to future climate change. Compare to the distribution map of Asiatic black bears evaluated by IUCN, Habitat suitability by the Maxent model were regionally diverse in extant areas and low in the extinct areas from IUCN map. This can be the result reflecting the regional difference in the environmental conditions where Asiatic black bears inhabit. As for the environment affecting the potential habitat distribution of Asiatic black bears, inhabitation rate was the highest, according to land coverage type, compared to climate, topography and artificial factors like distance from road. Especially, the area of deciduous broadleaf forest was predicted to be preferred, in comparison with other land coverage types. Annual mean precipitation and the precipitation during the driest period were projected to affect more than temperature's annual range, and the inhabitation possibility was higher, as distance was farther from road. The reason is that Asiatic black bears are conjectured to prefer more stable area without human's intervention, as well as prey resource. The inhabitation range was predicted to be expanded gradually to the southern part of India, China's southeast coast and adjacent inland area, and Vietnam, Laos and Malaysia in the eastern coastal areas of Southeast Asia. The following areas are forecast to be the core areas, where Asiatic black bears can inhabit in the Asian region: Jeonnam, Jeonbuk and Gangwon areas in South Korea, Kyushu, Chugoku, Shikoku, Chubu, Kanto and Tohoku's border area in Japan, and Jiangxi, Zhejiang and Fujian border area in China. This study is expected to be used as basic data for the preservation and efficient management of Asiatic black bear's habitat, artificially introduced individual bear's release area selection, and the management of collision zones with humans.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.381-388
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• 2016

The purpose of this study is to integrate and visualize using mapping techniques based on precise seabed geomorphology, seafloor backscattering images and high-resolution underwater images of the nearshore area around the Dokdo, in the East Sea. We have been obtained the precise topography map using multibeam echosounder system around the nearshore area(~50 m) of the southern part of the Seodo. Side scan sonar survey for analysis seafloor backscattering images was carried out in the same area of topography data. High-resolution underwater images(zone(a), zone(b), zone(c)) were taken in significant habitat scope of the nearshore area of the southern part of the Seodo. Using the results of bathymetry, seafloor backscattering images, high-resolution underwater images, we performed an integrated visualization about the nearshore area of the Dokdo. The integrated visualizing techniques are possible to make the seabed characteristic mapping results of the nearshore area of the Dokdo. The integrated visualization results present more complex and reliable information than separate geological products for seabed environmental mapping study and it is useful to understand the relation between seafloor characteristics and topographic environments of the study area. The integrated visualizing techniques and mapping analysis need to study sustainably and periodically, for effective monitoring of the nearshore ecosystem of the Dokdo.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.37-48
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• 2019

This study, which starting from Yangyang Jukdo's topography formation and questioning revealed in landscape guide and landscape commentary board, is to sort out the characteristics of Jukdo natural landscape through literature research, field observation research and stakeholder interview as part of the proper recognition of Jokdo landscape and search for landscape resources, and pursued a review of nominations and criticism. The results of this study are summarized as follows. Yangyang Jukdo is an island named because it was full of blue bamboo. From before the first half of the 14th Century. to the middle of the 18th Century., there was a Gwanlan-pavilion to see the sea and the bamboo in the west. The time when the original island, the Jukdo, have been a land-tied island connected with the land by the tombolo formed by the erosion of the sand. It is located at the end of the 14th Century. and before the middle of the 18th Century. In Jukdo, colorful weathered terrains, coastal terrain, and structural terrain formed by long-time weathering are found. Among them, the type of weathering, the tafoni style and the gnamma style are the scenic landscapes with the key stories of legend and poetry that are brought to Jukdo. In addition, there are seven kinds of letters caved in the rocks in Jukdo. The rocks found on the coast, basketball cannons, shrines, and sutras are seen as shrouds based on a Taoist hermit motifs and style. In addition, it can be interred from the photography of "jeongssisejeog" that the souvenir of Jukdo was the family of Chogyejeong of mid 18th Century. In terms of observational geography and poetry, Jukdo has been handed down a great deal of missionary color with key motifs such as 'Jukdo-seongoo', 'Jukdo-Dolgooyoo', or 'Stone mortar of Taoist hermit' It is proved that the pearl which is called 'The stone of the Taoist hermit' is a porthole formed in a separate space rather than the topography of the geomorphology in terms of shape, size and function. Currently named Shun-tang is a product of the ridiculous 'naming' of interest. The present landscape guide and commentary is not only incompatible with the place of Jukdo, but also does not match the traditional cultural landscape. Future scenery information such as guide signs and commentary boards should be improved in the direction of positively highlighting the stories and motifs related to the present that are present in order to enhance the landscape identity of Yangyang Jukdo.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.62-74
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• 2015

This study was carried out to provide examples of planting methods for the construction of street green spaces with abundant greenery by analyzing road type, surrounding land use and planting structures in street green spaces on Port Island, Kobe, Japan. Port Island_(total area: 826ha) is a marine cultural city located in Japan's first artificial island with facilities of urban function and port facilities. The study site was designated at 11 plots of $55{\sim}285m^2$ on Port Island, and topography structure styles were divided into four types with mounding style, slope style, slope and flat style, flat style according to the adjacent roads width. The area adjacent to the middle roads with high levels of noise and pollution set up the mounding style, slope style, slope and flat style of multi-layer structures using topographic properties. The area adjacent to small roads focused on a green strip with shrubs on a flat style. Surrounding land-uses include a public institution, housing complex, and a commercial building. The planting concept was a buffer and landspace function in case of the middle road_(lane 4) while the small road_(lane 2) was a landspace function. Planting species were diverse with Liquidambe formosana, Cinnamomum camphora, Sapium sebiferum, Cedrela sinensis, Laeocarpus sylvestris var. ellipticus, Ginkgo biloba, Prunus serrulata var. spontanea, Zelkova serrata, Quercus glauca, Juniperus chinensis, Magnolia kobus, Rhododendron spp., Camellia japonica, Abelia mosanensis, etc. Planting density was 0.02~0.08(0.04) individual/$m^2$ at the canopy layer, 0.02~0.08(0.04) individual/$m^2$ at the understory layer. Ratio of green coverage was 40.0~173.7(93.0)% at the canopy layer, 2.1~79.8(34.9)% at the understory layer and 17.9~64.2(32.9)% at the shrub layer. $Gr{\ddot{u}}volumenzahl$ was $1.43{\sim}6.67(4.13)m^3/m^2$ at the canopy layer, $0.02{\sim}2.01(0.85)m^3/m^2$ at the understory layer and $0.14{\sim}0.58(0.26)m^3/m^2$ at the shrub layer. The ratio of green coverage of street green space on Port Island was higher than that of Seoul, and particularly, the ratio of green coverage and $gr{\ddot{u}}volumenzahl$ at the shrub layer differed, compared to the main street green space in Korea. The result of this study may be applicable to other coastal reclaimed cities in terms of setting methods for street greenery considering the topography structure, planting structure and planting function.

• Economic and Environmental Geology
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• v.47 no.5
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• pp.533-540
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• 2014

The Wangdol-cho area, in the Hupo Bank, plays a very important role in main fishing grounds, leisure tourism and marine environmental researches of the East Sea. We analyzed the detailed bathymetry and classified the seabed characteristics of the Wangdol-cho area, based on seafloor backscattering images and sediment grain size. The Hupo Bank is developed in parallel with the eastern coastal line of Korean peninsula, and the shallowest area (Wangdol-cho) of the Hupo Bank is located along the eastern part of Hupo Port. The Wangdol-cho comprises three summits; north summit, middle summit, and south summit. The middle summit area among the three summits has the most shallow water depth with minimum about 6 m. The north summit shows about 8 m minimum depth and the south summit about 9 m. The bathymetry data around three summits represent undulating seabeds with many scattered underwater reefs and shallow water depth. The area between the underwater reefs, the flat seafloor in the northeastern part of the survey site, and the western steep slope area have relatively coarse sediments such as sandy gravel and gravelly sand. The bathymetry in the western side of the Wangdol-cho shows steep slope seabed, extending to the Hupo Basin. Fine sediments including mud and silty sand occur in the Hupo Basin area of the survey site. The submarine detailed topography and the analysis of the seafloor characteristics of the survey area are expected to contribute to management for marine environmental researches and sustainable use of ecosystems in the Wangdol-cho.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.121-128
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• 2012

High resolution intertidal DEM is a basic material for science research like sedimentation/erosion by ocean current, and is invaluable in a monitoring of environmental changes and practical management of coastal wetland. Since the intertidal zone changes rapidly by the inflow of fluvial debris and tide condition, remote sensing is an effective tool for observing large areas in short time. Although radar interferometry is one of the well-known techniques for generating high resolution DEM, conventional repeat-pass interferometry has difficulty on acquiring enough coherence over tidal flat due to the limited exposure time and the rapid changes in surface condition. In order to overcome these constraints, we tested the feasibility of radar interferometry using Cosmo-SkyMed tandem-like one-day data and ERS-ENVISAT cross tandem data with very short revisit period compared to the conventional repeat pass data. Small temporal baseline combined with long perpendicular baseline allowed high coherence over most of the exposed tidal flat surface in both observations. However the interferometric phases acquired from Cosmo-SkyMed data suffer from atmospheric delay and changes in soil moisture contents. The ERS-ENVISAT pair, on the other hand, provides nice phase which agree well with the real topography, because the atmospheric effect in 30-minute gap is almost same to both images so that they are cancelled out in the interferometric process. Thus, the cross interferometry with very small temporal baseline and large perpendicular baseline is one of the most reliable solutions for the intertidal DEM construction which requires very accurate mapping of the elevation.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.77-88
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• 2007

Following a successful bathymetric mapping demonstration in a previous study, the potential of airborne EM for seafloor characterisation has been investigated. The sediment thickness inferred from 1D inversion of helicopter-borne time-domain electromagnetic (TEM) data has been compared with estimates based on marine seismic studies. Generally, the two estimates of sediment thickness, and hence depth to resistive bedrock, were in reasonable agreement when the seawater was ${\sim}20\;m$ deep and the sediment was less than ${\sim}40\;m$ thick. Inversion of noisy synthetic data showed that recovered models closely resemble the true models, even when the starting model is dissimilar to the true model, in keeping with the uniqueness theorem for EM soundings. The standard deviations associated with shallow seawater depths inferred from noisy synthetic data are about ${\pm}5\;%$ of depth, comparable with the errors of approximately ${\pm}1\;m$ arising during inversion of real data. The corresponding uncertainty in depth-to-bedrock estimates, based on synthetic data inversion, is of order of ${\pm}10\;%$. The mean inverted depths of both seawater and sediment inferred from noisy synthetic data are accurate to ${\sim}1\;m$, illustrating the improvement in accuracy resulting from stacking. It is concluded that a carefully calibrated airborne TEM system has potential for surveying sediment thickness and bedrock topography, and for characterising seafloor resistivity in shallow coastal waters.

• Journal of Environmental Policy
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• v.14 no.4
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• pp.103-123
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• 2015

To provide effective management policy of geo-heritages, concept of Korean geo-heritage has been organized based on geo-diversity, geo-conservation, geo-tourism, and earth-heritage. In addition, current status of geo-heritage in Korea has been grasped, and categorized. In case GPS (Global Positioning System) coordinates exist, spatial information was constructed as GIS (Geographic Information System). Geo-heritages were classified into a total of six categories of natural monument, scenic site, coastal sand-dune, natural cave, world nature heritage, and other types of geo-heritage. By mapping 991 geo-heritages scattered nationwide using geographical information, all statuses can now be readily identified and enable the analysis of the distribution tendencies and correlation with topography. This study was aimed at searching the political connection based on quantitatively organized and analyzed geo-heritages, which have not been mapped thus far. In addition, this study organized data that have existed only in literature, and presented example verification. Moreover, these can be used as guidelines for the future search, discovery, registration and management of geo-heritage. If additional geo-heritages are discovered in field studies or with satellite images, then more correlations may be identified and help facilitate the research on geo-heritages management plans.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.200-207
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• 1997

In order to evaluate the soil microbiological characteristics of paddy fields in Korea, surface soils were sampled from 63 sites in different agroclimatic zones before submersion of the fields. The distribution of microorganisms and the microbial diversity indices were examined. Soil microbial populations were generally higher in southern area than in northern area. The colony forming units(cfus) of fluorescence Pseudomonas sp. showed the greatest regional differences, among the microbes investigated. On the topographical differences, the cfus of aerobic bacteria, fluorescence Pseudomonas sp. and Azotobacter sp. maintained high level in coastal plains; and on the sail textural difference, fungus was the highest in clay soil, but Bacillus sp., Azotobacter sp and denitrifiers were the highest in silty clay loam soil at 0.05 probability level based on the multiple range test. The numbers of ammonium oxidizers and Azotobacter sp. were increased with soil pH. Microbial diversity indices of paddy fields which calculated from the percentages of Bacillus sp. fluorescence Pseudomonas sp. Azotobacter sp. denitrifiers, ammonium oxidizers, nitrite oxidizers, actinomycetes and fungus to these total microbial numbers were between 0.109 and 0.661. On the soil textures, the microbial diversity indices of sandy, sandy loam, silty clay loam, clay loam and clay soil were 0.443, 0.427, 0.414, 0.405 and 0.362 respectively.