• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.103-114
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• 2021

The purpose of this study is to provide basic data for habitat restoration by implementing a series of processes of capturing and translocating Kaloula borealis and managing them in artificial breeding facilities. The study site in Samcheon, Jeonju-si, Jeollabuk-do was a waste landfill site in the past, and Kaloula borealis was found during the Samcheon Ecological River Restoration Project around March 2018. To restore the habitat, a plan was established to capture, translocate, artificially breed, and release Kaloula borealis at the site. The capture methods of adult Kaloula borealis were pitfall trap and drift fence, direct capture, and deep barrels. During 2018-2019, 86 adults of Kaloula borealis were captured and translocated to artificial breeding facilities. VIE-tagging was inserted under the skin for monitoring. For artificial breeding, Gryllus bimaculatus with oyster powder and vegetables were regularly supplied to feed Kaloula borealis. At the end of October 2020, 150 young Kaloula borealis raised in artificial breeding facilities were found not entering hibernation, so they were managed in a separate artificial breeding facility. Some young and adult Kaloula borealis currently hibernating will be scheduled to be continuously managed in artificial breeding facilities and released to the restored habitat in the spring of 2021.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.147.1-147
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• 2001

No Abstract, See Full Text

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.833-844
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• 2004

In Chugaryeong rift valley, lava plateau formation by the fissure eruption had vanished original landforms and effected on drainage derangement and revision. 4 rivers including Namdae-cheon, Bukhan-gang, Imjin-gang and Hantan-gang watersheds have shared Cheolwon-Pyeonggang lava plateau, that is, ownerless watershed. Main agency of the dividing process are central-eruption volcanic peaks such as Orisan(453m) and 680 Peak. Especially, Orisan has played the role of divide point for 4 watersheds. In the lower-relief plateau zone, complex drainage system have caused continually river capture between neighboring watersheds. In more elevated range slope, river capture have proceeded to headward erosion. Hydrogeomorphologically, lava-filled valley has initiated decrease of the original size of flood plain, maybe, causing higher capability of inundation by heavy rains, and then more active dissection of lava plateau layer.

• Animal Systematics, Evolution and Diversity
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• v.29 no.1
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• pp.18-22
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• 2013

A recent study on the mitochondrial genetic variation of the Carassius auratus population in South Korea suggested that there are 3 distinct mitochondrial lineages in the country, and that they are geographically separated between westward rivers and southward rivers, respectively. In this study, the population genetic structure of amplified fragment length polymorphism (AFLP) of Carassius auratus was investigated. The results of analysis of molecular variance (AMOVA) supported the geographic distinction between westward and southward river populations, but only 3.66% of total genetic variance lies among these populations. The panmicticity of the AFLP genetic variation is backed up by the results of the neighbor-joining dendrogram drawn from a linearized pairwise $F_{ST}$ matrix and Bayesian clustering analysis. The discordance of genetic structure between mitochondrial and AFLP genetic variation may come from difference in effective population size between these markers and/or gene flow between westward and southward river populations through river capture events.

• Korean Journal of Ecology and Environment
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• v.37 no.4 s.109
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• pp.400-405
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• 2004

Since a large bank-protection works project was undertaken during winter in the middle reaches of the Chikuma, the riverbed structure was drastically altered. In order to assess the short-term impact of bank-protection works on the abundance Pattern of Stenopsyche marmorata (Trichoptera) from spring to early summer, we conducted an investigation on the capture of adults using light traps before and after construction work. The patterns of the daily capture of S. marmorata and the Namely, after construction, the daily catch of adult numbers increased only slightly during the investigation periods. This suggested that the age structure of the S. marmorata larval population had changed in the construction area. Our data suggest that bank-protection projects impact the abundance pattern of adult caddisflies in the river ecosystem.

• Journal of the Korean Geographical Society
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• v.48 no.5
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• pp.615-628
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• 2013

The waterfall can be formed by difference between the height of up and down part in new channel, is formed by channel avulsion that rapidly changing of river channel course. This study described types and processes of waterfalls by channel avulsion, and analyzed rates and factors of waterfall recession, on object to 7 waterfalls in South Korea. Bulyeong falls at Uljin-gun, Yongchu falls at Yeongdeok-gun, Jikyeon falls at Yanggu-gun and Gwangpum falls at Uljin-gun are formed by natural incised meander cutoff. Samhyeongje falls at Taebaek-si and Guryong falls are formed by river capture processes, and Palbong falls at Chungju-si is formed by artificial channel cutting for farm land secured. The locations of waterfalls gradually moved to upstream over time by head erosion. The recession rates were measured by 3~4m/ka on Bulyeong falls, Yongchu falls, Jikyeon falls and Samhyeongje falls, to estimate of formation age. Recession rates of these 4 waterfalls were analyzed that have clearly positive correlations with drainage area, precipitation, corrosion and weathering capability of bedrock, and initial height of waterfall.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.356-365
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• 2024

The study was conducted in the Terie River between January and April 2022. The objectives of the study were to assess the fish species composition, determine the length-weight relationship and condition factor and assess the water quality of the river using international water quality guideline for aquatic life. Gillnets with different mesh sizes, 4, 6, 8 and 10 cm were used to collect fish specimens in both dry and wet seasons. Immediately after capture, the total length (TL) and total weight (TW) of each individual were measured in centimeters and grams, respectively, and their relationship was determined using the power function. The physicochemical water quality parameters were analyzed using standard procedures and wagtech portable water quality Kits and Secchi Disk apparatus. A total of 667 fish specimens were collected from the Terie River, 410 and 257 in dry and wet seasons respectively. A total of six fish species, Oreochromis niloticus, Labeobarbus intermedius, Labeobarbus nedgia, Labeobarbus beso, Clarias gariepinus, and Ramius loti were recorded. For length-weight relationship and condition factor analysis, more abundant fish species (O. niloticus and L. intermedius) which were found in both seasons were selected. The length and weight relationship of L. intermedius were TW = 0.0073TL^3.04 in dry and TW = 0.0337TL^2.59 in we season indicated isometric and negative allometric growth respectively. While O. niloticus showed negative allometric growth, TW = 0.096TL^2.44 and TW = 0.0335 TL^2.76 in dry and wet seasons, respectively. The mean Fulton condition factor (FCF) of L. intermidus were 0.85 ± 0.03 and 0.94 ± 0.25 in dry and wet seasons, respectively. The FCF of O. niloticus was 1.70 ± 0.13 and 1.73 ± 0.12 in dry and wet seasons respectively. Except for ammonia, the physicochemical water quality parameters were with the permissible limit for aquatic life and are suitable for fishes Terie River. The river has commercially important fish specimens that could be used for food security and livelihood improvement. However, there is very limited fishing activity in the river due to less awareness on the value of fishes. Therefore, sustainable fishery development should be done in the river.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.181-184
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• 2007

Up to now, a lot of houses, roads and other urban facilities have been damaged by natural disasters such as flash floods and landslides. It is reported that the size and frequency of disasters are growing greatly due to global warming. In order to mitigate such disaster, flood forecasting and alerting systems have been developed for the Han river, Geum river, Nak-dong river and Young-san river. These systems, however, do not help small municipal departments cope with the threat of flood. In this study, a real-time urban flood forecasting service (U-FFS) is developed for ubiquitous computing city which includes small river basins. A test bed is deployed at Tan-cheon in Gyeonggido to verify U-FFS. Wireless sensors such as rainfall gauge and water lever gauge are installed to develop hydrologic forecasting model and CCTV camera systems are also incorporated to capture high definition images of river basins. U-FFS is based on the ANFIS (Adaptive Neuro-Fuzzy Inference System) that is data-driven model and is characterized by its accuracy and adaptability. It is found that U-FFS can forecast the water level of outlet of river basin and provide real-time data through internet during heavy rain. It is revealed that U-FFS can predict the water level of 30 minutes and 1 hour later very accurately. Unlike other hydrologic forecasting model, this newly developed U-FFS has advantages such as its applicability and feasibility. Furthermore, it is expected that U-FFS presented in this study can be applied to ubiquitous computing city (U-City) and/or other cities which have suffered from flood damage for a long time.

• Journal of information and communication convergence engineering
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• v.22 no.2
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• pp.133-138
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• 2024

Dissolved oxygen (DO) is an important factor in ecosystems. However, the analysis of DO is frequently rather complicated because of the nonlinear phenomenon of the river system. Therefore, a convenient model-free algorithm for DO variable is required. In this study, a data-driven algorithm for predicting DO was developed by combining XGBoost and an artificial neural network (ANN), called ANN-XGB. To train the model, two years of ecosystem data were collected in Anyang, Seoul using the Troll 9500 model. One advantage of the proposed algorithm is its ability to capture abrupt changes in climate-related features that arise from sudden events. Moreover, our algorithm can provide a feature importance analysis owing to the use of XGBoost. The results obtained using the ANN-XGB algorithm were compared with those obtained using the ANN algorithm in the Results Section. The predictions made by ANN-XGB were mostly in closer agreement with the measured DO values in the river than those made by the ANN.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.158-158
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• 2022

Ecological drought consequences have received a lot of attention in recent years. Thus, ecological drought was proposed as a new drought category to characterize the impact of drought on ecosystems. The current study used a unique drought index, the standardized supply-demand water index (SSDI), and a run theory to detect ecological drought occurrences and characteristics such as drought-affected area, drought severity, drought duration, drought frequency, and drought orientation in the Hwang River, an environmentally valuable region. Hence, to assess drought-prone areas, the bivariate probability and return period will be calculated using a two-dimensional joint copula. The core results show that (a) the Spatio-temporal characteristics of ecological drought were successfully recognized using the spatial and temporal identification approach; (b) in comparison to the SPEI meteorological drought index, the SSDI is more credible and can more readily and effectively capture the entire properties of ecological drought information; (c) the Hwang river had seen the most severe drought occurrences between the late 1990s and the mid-2020s, with 48.3 percent occurring before the twenty-first century; (d) Severe ecological drought occurrences occurred more frequently in most areas of the Hwang River (e) Only the drought duration and severity in the Hwang area were more responsive to temperature when temperatures rise around 1.1℃, the average drought duration and severity rise around 16 % and 26 %, respectively. This suggested that the Hwang River has been exposed to more severe heat stress in the twenty-first century. Thereupon droughts in the twenty-first century occurred with bigger affected regions, longer durations, higher frequency, and more intensity.