• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.19-29
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• 2012

The purpose of this study is to suggest improvements of Eco-Natural map preparation guideline by presenting assessment methods that can be applied to the result of river ecosystem health survey and assessment, using the Geographic Information System. The area for studying is the main stream of the Hwang River where is easy to collect data and available to compare before and after of river assessment. It was reevaluated by reflecting the result of river ecosystem health assessment of the Ministry of Environment. As the result, Eco-Natural map of the study area reflecting the river assessment, the changes in the area ratio by grade have been increased from 1.14% to 14.03% in the first-grade and from 24.64% to 43.91% in the second-grade. It is considered to present more realistic grade due to the assessment of the rivers that have not been reflected in the meantime. Consequently, the result of this study will be useful for establishing the development projects on the rivers, providing the foundation for more realistic and active protection.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.1
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• pp.35-50
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• 2002

This study aims to understand wetland distribution and type-specific classification features with a focus on Tumen River downstream in China by adjusting and improving the classification system used in Korea with a reference to international wetland classification systems and their criteria & methods. In this study, wetland types were determined based on hydrology, vegetation, and soil conditions, which are the most basic elements of wetlands. Also, topography analytical map, vegetation analytical map, and soil analytical map for wetland classification were developed and used based on currently available topography map, vegetation map, and soil map. In addition, codes were defined based on topography, location, hydrology, and vegetation. The result shows that, in the Tumen River downstream, wetlands are often found near natural revetment and terrace land & river-bed lakes. In the discovered wetlands, riverine, lacustrine, and inland wetlands were mostly found at system level. Riparian and human-made wetlands were also identified. At a sub-system level, perennial and seasonal wetlands were found to a similar degree. At a class level, perennial open water, herbal plants, and shrubs were mostly found and sandy plain, hydrophytes, and forest tree types were also observed. An overall detailed classification shows that a total of 17 wetland types were found and a large distribution of sand dunes and river-bed lakes, which are scarce in Northeast Asia, indicates that other rare wetland types such as palustrine seasonal sand plain wetland and lacustrine seasonal sand plain wetland may be discovered.

• Journal of Environmental Impact Assessment
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• v.14 no.6
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• pp.377-385
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• 2005

The Eurasian otter(Lutra lutra) is listed as No. 330 in natural monument. To manage and conserve habitat for otters, it is critical to understand which habitat components are important for otters. The objectives of this study were to analyze otter habitat characteristics in accordance with land-cover map. We investigated otter spraints and sprainting site in Geoje Island from January to December, 2004. with GPS coordinates. The analysis of otter habitat use pattern was used by Arcview ver. 3.2 with 1: 25,000 Topology Map and field data. Otter habitat use was strongly related to sites in riparian vegetation riparian(dam or river) structures. In this study, Gucheon was a site with high coverage of riparian vegetation and unconfined channels, thus recording higher number of spraint densities than those of Yeonchocheon. Yeonchocheon was under construction at lower stream areas so that otter habitat use was limited. This study suggests that securing suitable forests and riparian vegetation zone is essential for conservation of otters.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.106-119
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• 2016

Flood risk map, flood damage map, disaster information map, inundation trace map are involved with the cartographic analysis of flood inundation based on prevention, preparation, restoration, response from natural disasters such as flood, flooding, etc. In this study, the analysis for channel and basin characteristics Chungju dam to Paldang dam of South han river after four river project. Flood scenario is selected to take advantage of design flood level of schematic design for river. Flood inundation of one dimensional non-uniform flow by using HEC-RAS with basin characteristics is accomplished and two dimensional unsteady flow was interpreted by using FLUMEN. Frequency analysis is carried out about each abundance of South han river for 100 year period, 200 year period and 500 year period. Flooding disaster area of 100 year period on 0.5m damage functions is 2378.8ha, 200 year period on 0.5m damage functions is 3155.2ha, 500 year period on 0.5m damage functions is 3995.3ha respectively. It will be significant data for decision making to establish inundation trace map for providing basic plan for river maintenance, land use plan, flood protection plan, application plan and getting information of flood expectation area.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.272-275
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• 2005

The digital map expresses natural topographies and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, the digital map is regarded as an important factor in the information-oriented society. However, it is difficult to maintain the most recent topographic information all the times because of restricted budget and time. For that, the efficient method corresponded with the digital map should be presented. This study aims to suggest the way to make an estimate of updating cost for 1:5,000 scale digital map by using remotely sensed data. To predict updating area of the digital map, the screen digitizing method was applied to the overlapped images and digital maps.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.465-471
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• 2004

The digital map expresses natural topographies and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, the digital map is regarded as an important factor in the information-oriented society. However, it is difficult to maintain the most recent topographic information all the times because of restricted budget and time. For that, the efficient method corresponded with the digital map should be presented. This study aims to suggest the way to make an estimate of updating cost for 1:5,000 scale digital map by using remotely sensed data. To predict updating area of the digital map, the screen digitizing method was applied to the overlapped images and digital map

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.391-396
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• 2003

The digital map expresses natural topography and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, those should contribute to the information-oriented society by maintaining information and providing it to users quickly. However it is difficult to maintain the most recent topographic information all the time because of restricted budget and time. The purpose of this study is to investigate and analyze the updating area of the digital map using remotely sensed data, and to furnish the useful information reducing cost and time. To predict updating area of the digital map, we applied the urban changes analysis method to Landsat TM images from produced date of the digital map to up-to-date. Classification method for urban change analysis applied single band process algorithm. This study presents that updating area of the digital map is predicted by only the rate of 40% on total research area.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.235-246
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• 2021

This study investigated the impact of baseflow on fish community in the Ungcheon stream (16.5 km long) located downstream of the Boryeong Dam, Korea. Based on field monitoring, there were five dominant fish species in the Ungcheon Stream accounting for 75% of the total fish community: Zacco platypus, Zacco koreanus, Tridentiger brevispinis, Rhinogobius brunneus, and Pungtungia herzi. These five fish species were selected as target species. HydroGeoSphere (HGS) and River2D models were used for hydrologic and hydraulic simulations, respectively. A habitat suitability index model was used to simulate fish habitat. To assess the impact of baseflow, each representative discharge was examined with or without baseflow. The HGS model was used to calculate baseflow within the study reach. This baseflow was observed to increase gradually with longitudinal distance. Validation of the hydraulic model dem onstrated that computed water surface elevated when baseflow was included, which was in good agreement with measured data, as opposed to the result when baseflow was excluded. Composite suitability index distributions and weighted usable area in the study reach were presented for target species. Simulations indicated that the baseflow significantly increased habitat suitability for the entire fish community. These results demonstrate that there should be a substantial focus on the baseflow for physical habitat simulation.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.398-405
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• 2022

The research was based on long-term studies on the major physico-chemical and hydrological factors and zooplankton community dynamics in the Hwang River. We had 341 times survey and collected zooplankton samples in the Hwang River of mid-Nakdong River from 1995 to 2013. We identified 97 zooplankton species, including 77 rotifers, 16 cladocerans, and 4 copepods. The total zooplankton abundance and species diversity were shown distinctive temporal variation (ANOVA, p<0.001). Annual average of zooplankton population density was 58.4±3.2 ind L^-1 (n=341) and the lowest was 17.0±3.8 ind L^-1 (1996, n=20), while the highest was 151.5±32.3 ind L^-1 (2010, n=22). For zooplankton, small rotifer groups(e.g., Keratella sp., Brachionus sp., Trichotria sp.) dominated the study site for 19 years survey. Statistical analysis revealed that there were positive relationships with SiO₂ (p=0.002) and water level (p<0.001) for the high abundance of rotifer community. There were considerable variations both the total cladocerans population and the number of cladocerans' species concerning annual precipitation. Despite the appearance of various zooplankton in the Hwang River, the mean population density remained low. Due to the lateral structures in the Nakdong River, the downstream basin of the Hwang River is inevitably affected. The zooplankton community in our study site is considered to be mainly influenced by external factors that can stably increase and maintain the volume of the water body and internal factors that induce an increase in food sources through the inflow of nutrients into the water body.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.257-266
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• 2018

East China Sea (ECS) is known to be supplied with large amounts of sediments form Huanghe, Changjiang and various rivers in Korea. Many studies have been conducted to identify the effects of rivers and deposition process of ECS, but no consensus has been reached. In this study, clay minerals, rare earth elements (REEs) and grain size were analyzed to study the provenance and sedimentation environment of core 99MAP-P63 in ECS. Clay mineral contents of 99MAP-P63 are abundant in order of illite, chlorite, kaolinite, and smectite. The provenance of 99MAP-P63 sediments using clay minerals is interpreted as the Changjiang regardless of depth. As a result of REEs analysis, 99MAP-P63 sediments are very similar to Chinese rivers sediments. Therefore, the provenance of 99MAP-P63 is Changjiang, and the influence of Korean river seems to be insignificant. 99MAP-P63 sediments are generally classified as sandy silt, but the top of the core is divided into sand with a sand contents of 85 %. Compared with surrounding cores, sandy silt sediments arecorresponded to the low stand stage when sea-level was low, and the sediments were thought to have been supplied directly through the paleo-Changjiang. Sandy sediments in uppermost of core are corresponded to transgressive stage. Although distance from estuary was increased due to sea-level rise, it was possible to supply coarse sediments due to high bottom stress, and the paleo-Changjiang sediments deposited in study area were re-deposited.