GEO DATA

Joo-Hyung Ryu

10 Articles

UAV Photogrammetry and LiDAR Based Dataset of Spartina anglica Distribution and High-resolution Topographic Map in Ganghwado: Keunyong Kim, Yeongjae Jang, Jingyo Lee, Joo-Hyung Ryu; GEO DATA. 2022;4(2):1-8. Published online June 30, 2022; DOI: https://doi.org/10.22761/DJ2022.4.2.001

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The Spartina anglica in the tidal flat at the southern part of Ganghwado, it is known that the distribution area has gradually expanded since it was officially announced as invasive alien species in 2015. The government and local governments are continuing their efforts to remove the S. anglica, and for this, continuous distribution change monitoring is required. This study extracted the data of distribution and extent area of S. anglica from Zenmuse P1 sensor, and generated the high-resolution Digital Elevation Model (DEM) from Zenmuse L1 sensor. Optical and Lidar images were photographed at an altitude of 70 m, and Ground Sampling Distance (GSD) of optical images was obtained at 0.9 cm and GSD of lidar images at 5 cm spatial resolution. However, the data are resampled and provided in GSD 25 cm to comply with the "National Spatial Information Security Management Regulations of the Ministry of Land, Infrastructure and Transport" and "Security Business Regulations of the National Intelligence Service".

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Spartina anglica-Derived Carbon-Coated PE Separator for Physically Restraining Polysulfide Migration in Lithium-Sulfur Batteries
Ye Jin Jeon, Yuna Ha, Jang Kyun Kim, Youn-Jung Kim, Taeeun Yim
Korean Journal of Chemical Engineering.2024; 41(4): 1187. CrossRef

A Geological Environment Characteristics Dataset of Tidal Flat Surface Sediments: A 2021 Pilot Study of the Gomso Bay Tidal Flat Area to Use of Sediment Type Data: Kyoungkyu Park, Han Jun Woo, Hoi-Soo Jung, Joo Bong Jeong, Joo-Hyung Ryu, Jun-Ho Lee; GEO DATA. 2022;4(2):9-22. Published online June 30, 2022; DOI: https://doi.org/10.22761/DJ2022.4.2.002

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The Gomso Bay tidal flat is located between Buan-gun and Gochang-gun in Jeollabuk-do, Korea; it is a semi-closed bay in an area where tides prevail over waves. Tidal flats are mainly found south of Gochang-gun, and the main stream located north of the tidal flats is about 15 m deep and 900 m wide at low tide. Limited direct sampling is necessary for analyzing the geological environment of intertidal tidal flats, depending on the expected ebb-tide time and the number of survey items allowed for tidal flat access. This study assessed field measurement and laboratory analysis items for obtaining and establishing geological environment data to use of sediment type data in a pilot research area in the Gomso Bay tidal flat. Thirty sites were examined on June 22 and 24, 2021 (survey time about 3.5 hours for the 2 days). The field measurements were the sample date (year/month/day/hour/minute), ellipsoid height using a real-time kinematics global positioning system (RTK GPS) (m), shear strength (kg/cm²), and Munsell color. Samples for particle size (phi, Φ), specific density, porosity (%), moisture content (%), total organic carbon (%), total carbon (%) and total nitrogen (%) were placed in zipper bags and polypropylene (PP) bottles. The sedimentary phases were classified following Folk and Ward (1957), the organic matter was characterized based on particle size analysis and each experimental result was verified. In the future, a geological environment characteristics dataset based on this pilot study will be used as basic data to assess changes in the tidal flat topography and sedimentation environment. It should be useful data for research, tidal flat environment conservation management and free open data for users of related researchers.

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Characteristics of temporal-spatial variations of zooplankton community in Gomso Bay in the Yellow Sea, South Korea
Young Seok Jeong, Min Ho Seo, Seo Yeol Choi, Seohwi Choo, Dong Young Kim, Sung-Hun Lee, Kyeong-Ho Han, Ho Young Soh
Environmental Biology Research.2023; 41(4): 720. CrossRef

The Dataset of UAV Based High-resolution Tidal Topography at the Nakdong Estuary: Focusing on Jin-u Island and Shin-ja Island: Yeongjae Jang, Jingyo Lee, Joo-Hyung Ryu, Kye-Lim Kim, Hahn Chul Jung, Keunyong Kim; GEO DATA. 2022;4(1):27-36. Published online March 31, 2022; DOI: https://doi.org/10.22761/DJ2022.4.1.003

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In the tidal flats of the Nakdong Estuary, eight weirs were installed as part of the Four Major River Restoration Project in 2011, and the environment changed from a flowing stream to a still water stream. As the Nakdong River’s weir was permanently opened in February 2022, the topography and ecological environment are expected to large change. In this study, Unmanned Aerial Vehicle (UAV) photogrammetry was conducted on the tidal flats of the Nakdong Estuary in November 2021, the environment before the Nakdong River floodgates were opened. The study area was surveyed using the Network-RTK (Real-Time Kinematic) method to obtain Ground Control Point (GCP), and using an UAV, orthographic image and digital elevation model were generated for an area of 3.47 ㎢ near Jin-u island and 2.75 ㎢ near Shin-ja island. A result of spatial resolution of 1.8 cm was obtained, the result was verified using checkpoints, and results with accuracy exceeding 1 cm were obtained in both Sin-u Island and Jin-woo Island. In the future, changes in the topography and sedimentation environment of this area are expected, so it will be useful data for various research and conservation management.

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Influence of Precipitation Conditions and Discharge Rates of River Estuary Barrages on Geomorphological Changes in an Estuarine Area
Sung-Bo Kim, Doo-Pyo Kim
Applied Sciences.2023; 13(17): 9661. CrossRef

TanDEM-X-based Ganghwa Tidal Flat High-resolution Topographic Map Construction and Service: Ga Ram Yun, Joo-Hyung Ryu, Kye Lim Kim, Jin Hyung Lee, Seung-Kuk Lee; GEO DATA. 2022;4(1):37-42. Published online March 31, 2022; DOI: https://doi.org/10.22761/DJ2022.4.1.004

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Abstract PDF: This study extracted the data of Digital Elevation Model (DEM), tidal channel, and tidal channel density, slope based on TanDEM-X satellite of Ganghwa tidal flat. Monitoring and analysis of the decrease in the area of tidal flats in Korea are of great importance, and by judging the efficiency and accuracy in time and space, satellite data were obtained according to the analysis topic of the tidal flats. Since the west coast occupies a large proportion of domestic tidal flats, Ganghwa-do tidal flats were designated as the scope of the study. The produced materials are provided in the form of GEOTIFF(.tif) or Shape(.shp) files. To utilize the tidal flat data constructed in this way, it can be downloaded from the Environmental Big Data website (www.bigdata-environment.kr), an environmental business big data platform.

Archive and distribution of VIIRS DNB data for the Northeast Asian Sea: Euihyun Kim, Joo-Hyung Ryu, Suk Yoon; GEO DATA. 2021;3(1):12-17. Published online March 31, 2021; DOI: https://doi.org/10.22761/DJ2021.3.1.002

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Night-time satellite data were first collected from the U.S. Air Force in 1972 for military purposes. Since then, it has been useful to understand the human activities in the fields of society, economy, culture, and science, etc. In the perspective of oceanography, the night-time satellite data has been used for monitoring purposes such as detecting night-time fishing boats. The Korea Ocean Satellite Center (KOSC) of the Korea Institute of Ocean Science & Technology (KIOST) has been directly receiving the Suomi National Polar-orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Day & Night Band (DNB) data since June 2016. It has been archived and distributed for about four years. In addition, the KOSC operates its own ground system, which pre-processing the data including the radiance transformation, conversion of coordinate system, terrain correction, and calibration of lunar irradiation effect for quality improvement. Currently, the contributed data is preprocessed within about an hour after the receiving, so it is evaluated the high efficiency and usefulness in terms of time. This has confirmed the feasibility of real-time information acquisition through the research in the field of night-time monitoring/observation missions in the Northeast Asian Sea and onshore disaster/accident monitoring. The KOSC is making efforts to utilize the distributed data in various research such as maritime domain awareness. From the second half of this year, the NOAA-20 data will be directly received and distributed as an additional night-time satellite data. In the future, it is expected that the more diverse data will be distributed through the research utilization and supports.

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Monitoring Maritime Ship Characteristics Using Satellite Remote Sensing Data from Different Sensors
Won-Kyung Baek, Euihyun Kim, Ho-Kun Jeon, Kwang-Jae Lee, Sang-Wan Kim, Yoon-Kyung Lee, Joo-Hyung Ryu
Ocean Science Journal.2024;[Epub] CrossRef

Above water remote sensing reflectance dataset on the coastal waters of California and Korea: Jee-Eun Min, Jeong-Eon Moon, Jong-Kuk Choi, Liane Guild, Joo-Hyung Ryu; GEO DATA. 2020;2(2):5-13. Published online December 30, 2020; DOI: https://doi.org/10.22761/DJ2020.2.2.002

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Abstract PDF: Remote sensing reflectance (R_rs) is a fundamental data of ocean color remote sensing that is used as an input data for algorithm development. In this study, the Rrs spectra acquired from the coast of Korea and California, on the opposite side of the Pacific Ocean, were analyzed and compared. The waters of Gyeonggi Bay and Mokpo had a similar spectrum to those of the waters inside of the San Francisco Bay, although the waters of each region had different characteristics. The South Sea in Korea showed similar spectral characteristics on the waters of Monterey Bay and outside of the San Francisco Bay in California. The upward slope of the Rrs spectra in the range of 400 to 600 nm obtained from the inside of the San Francisco Bay was higher than the coastal waters on the Gyeonggi Bay and Mokpo in Korea. The Rrs spectra showing peaks on 580 nm and 680 ~ 700 nm due to chlorophyll were similarly observed in the South and East Seas of Korea, and the coastal waters of Monterey Bay and the outside of the San Francisco Bay in California.

The Dataset of Sedimentary Environments at Hwangdo Tidal Flat on the Western Coast of Korea (2004 to 2013): Kye-Lim Kim, Jong-Kuk Choi, Joo-Hyung Ryu; GEO DATA. 2020;2(2):26-35. Published online December 30, 2020; DOI: https://doi.org/10.22761/DJ2020.2.2.005

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Abstract PDF: The Hwangdo tidal flat has been subjected to local hydrodynamic changes caused by the construction of seawalls and bridges, which are changing the distribution of sediments and topographic characteristics. These changes would affect the sedimentary environments. It is essential to establish sedimentary environments dataset such as sediment distributions and elevation in order to understand the sedimentary environments and the pattern of change in the tidal flat. Therefore, between 2004 and 2013, data on sedimentary environmental factors such as surface sedimentary facies and elevation were obtained through the field survey, and soil moisture content of each sediment was measured to analysis the correlation between seawater and optical reflectance in the tidal flat. As a result, 12 sedimentary facies were distributed in the Hwangdo tidal flat, and the sand content and elevation gradually increased between 2004 and 2013. It was also shown that the amount of seawater present in the surface decreased as elevation and grain size increased. These data will be useful for understanding the changes in the sedimentary environments and for establishing plans for change and conservation management in Hwangdo tidal flat.

Red tide dataset in the waters around the Korean Peninsula: Jisun Shin, Euihyun Kim, Keunyong Kim, Joo-Hyung Ryu; GEO DATA. 2019;1(1):13-24. Published online December 30, 2019; DOI: https://doi.org/10.22761/DJ2019.01.01.003

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Abstract PDF: Red tide blooms are increasing worldwide. Since 1995, Margalefidium polykrikoides blooms have occurred frequently in the waters around the Korean Peninsula. These blooms generally appear first on the South Sea of Korea in summer. When they occur on a large scale, they extend to the East Sea of Korea and the West Sea of Korea, causing great damage to fisheries and marine ecosystems. Harmless red tide can also adversely affect the environment of the waters by causing oxygen depletion in waters when occurring at high density. Currently, the National Institute of Fisheries Science (NIFS) is providing the daily red tide report based on M. polykrikoides red tide species. This report contains red tide species, location, and cell abundance information, but is limited to use as cell abundance data based on exact location. In addition, the waters around the Korean peninsula have different characteristics, so that the optical characteristics and seawater environment are different for each water. In the East Sea in Aug. 2013, the West Sea in Aug. 2016, the South Sea in Aug. 2018, and the South Sea in Aug. and Sep. 2019, during red tide season, dataset were obtained for red tide cell abundance, spectrum, chlorophyll concentration, and suspended particulate matter concentration. Noctiluca scintillans species were observed in the field survey conducted in 2016, and M. polykrikoides was mainly found in the other field surveys. Location-based red tide cell abundance data and seawater environment information obtained during red tide occurrence will be useful data for the construction of red tide warning system to reduce damage due to red tide blooms.

Chlorophyll and Total Suspended Materials Concentrations and Remote Sensing Reflectance Data measured at the Red Tide Area of Jinhae, Geoje, and East Sea during August from 1998 to 2003 and August 2013: Jeong-Eon Moon, Tai-Hyun Han, Kwang-Seok Kim, Deuk-Jae Hwang, Jae-Hyun Ahn, Jong-Kuk Choi, Joo-Hyung Ryu, Young-Je Park; GEO DATA. 2019;1(1):29-37. Published online December 30, 2019; DOI: https://doi.org/10.22761/DJ2019.01.01.005

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Abstract PDF: The chlorophyll and total suspended materials concentrations and remote sensing reflectance data were observed for red tides occurring every summer in waters around the Korean Peninsula. In observation area and date, the field survey were performed (1) in the Jinhae and Geoje coasts during August 1998, August 1999, August 2001, and August 2003, (2) in East Sea coast during August 2013. The remote sensing reflectance data were obtained from portable spectroradiometer. The chlorophyll concentration data were obtained from spectrophotometric method and the total suspended materials concentration data were obtained from filter-weight difference method. The remote sensing reflectance data were validated using Moon et al.(2012). The chlorophyll concentration data were validated using baseline correction and subtraction of 750 nm value, and the total suspended materials concentration data were validated using variation of humidity.

Unmanned aerial vehicle remotely sensed datasets, a reference dataset for coastal topography change and shoreline analysis: Bumjun Kim, Keunyong Kim, Joo-Hyung Ryu; GEO DATA. 2019;1(1):38-45. Published online December 30, 2019; DOI: https://doi.org/10.22761/DJ2019.01.01.006

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Abstract PDF: To analyze tendency of temporal and spatial change of coast using long-term topography and shoreline change data is important. In this study, high-resolution digital elevation model and orthorectified image data were generated using rotary-wing UAV(unmanned aerial vehicle) system for coastal topography and shoreline change analysis. The UAV system has advantage of low cost and high efficiency compared to satellite remote sensing platform so UAV system easily acquire time series image data. The spatial resolution of generated digital elevation model and orthorectified images are very high, in centimeter. Therefore, the above image data can be used in various fields of remote sensing and geography such as detailed coastal topography.

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