• Journal of Ecology and Environment
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• v.33 no.3
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• pp.237-244
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• 2010

In this study, we evaluated the distribution, habitat characteristics, and diet of two Korean freshwater turtle species (Chinemys reevesii, Pelodiscus sinensis) and an invasive turtle species (Trachemys scripta elegans) in the area surrounding the Seomjin River and the Nam River. We surveyed basking turtles in multiple locations along a 48-km stretch of the Seomjin River and in 99 reservoirs distributed along the Seomjin and Nam rivers from June to September, 2009. We observed 8 and 6 red-eared turtles in 3 reservoirs and at 3 sites in the Seomjin River, respectively, and 33 Reeve's turtles in 9 reservoirs. There were also 28 and 16 mud turtles detected at 15 sites along the Seomjin River and in 8 reservoirs, respectively. Among the 14 biotic and abiotic habitat characteristics that might influence the abundance of freshwater turtles in reservoirs, only the distance between a reservoir and the nearest residential areas was correlated negatively with abundance. With regard to the diet, all Reeve's and red-eared turtles investigated were determined to forage on water snails. Some turtles also foraged on vegetation and aquatic invertebrates. Additionally, we found fish in the stomach of one of the Reeve's turtles, and dragonflies in the stomachs of two red-eared turtles.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.41-56
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• 2016

In recent localized heavy rainfalls have been arising from abnormal climate change. People are concerning about damages with increasing the frequency of flooding. Therefore, we need to understand river hydraulic characteristics and management to reduce damage from flooding. To study hydraulic characterization of Sincheon experimental catchment HEC-RAS (Hydrologic Engineering Center River Analysis System) model which provided by U.S Army Corps of Engineers (USACE) was applied. This study analyzed and compared water level the frequency flood for 100 years and 200 years by clark unit Hydrography. The change of the water level of Daejeon bridge, Sincheon bridge and Singi bridge showed increased for all conditions. The flow rate for the Daejeon bridge and the Sincheon bridge showed an increase, but the Sinki bridge showed a decreasing flow rate overally, except for 1hour-100 years. The verification result showed that the model was able to simulate the water level with 0.4709 coefficient of determination and error ration ranging from 1 to 3%.

• Journal of The Geomorphological Association of Korea
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• v.23 no.3
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• pp.57-66
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• 2016

The objective of this study is to find out geomorphological characteristics of historical ruins where people produced and consumed large jar coffins excavated in the Yeongsan river basin using the map of old drainage network to restore distribution network. For this purpose, we chose the 21 consumption sites. The results are as follows. First of all, large jar coffins(relics, 47.6% of total) in the Yeongsan River basin were located in Sampo stream basin, almost all of them were located within the Yeongsan River main stream basin and Sampo stream basin. Also, distance from all consumption site to river was within about 2km. Therefore, it is thought that the all consumption sites are located at the place of the gift of nature that was very favorable to water transport of jar coffins. The results of this study may be used as basic data for research of cultural relics in the Yeongsan river basin.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.4
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• pp.275-283
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• 2007

This study aims at the calculation of a variation of flow characteristics of main channel for tributary inflow in river junction. So this study was analyzed the variation of flow depth and velocity in main channel for a change of inflow degree. For this purpose, FLDWAV model are carried out for variations of $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$ tributary inflow at junction. Results show that velocity ratio(V1/V3) increases and flow depth ratio(H1/H3) decreases for discharge ratio(Q1/Q3) of upstream and downstream when degree increases in junction. And FLDWAV model was applied at a real river junctions. Selected area is a junction of Gumho river and Sin stream. Results show that pattern is similar to a virtual channel.

• Journal of Korean Society of Rural Planning
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• v.24 no.4
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• pp.81-88
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• 2018

With the increase of the number of riverfront development projects an objective and systematized survey and assessment tool is required to understand and identify the characteristics and potentials of river environment for human uses. The purpose of this study was to develop an assessment system for the investigation and evaluation of the water-friendly environment and to examine its effectiveness by applying the system to the selected study sites. Literature reviews, expert consultation, and preliminary survey were conducted to select highly relevant indexes to evaluate water-friendliness in rivers and, as a result, an assessment system of ten items in four areas was established. The assessment system were applied to 139 reaches of six rivers including Bykgye Cheon, Seom River, Gap Cheon, Yudeng Cheon, Naesung Cheon, and Kumho River. The scores and grade of water-friendliness were calculated per rivers and reaches, and their differences were prominent according to urban river, rural river, mountainous area and city area. Bykgye Cheon and Naesung Cheon got high scores in visual quality and Kumho River and Gap Cheon in community needs and potential uses. The scores of each section in the same river can be used as a basic data for the selection of appropriate sites for the development of hydrophilic space. In addition, it is expected that identifying the characteristics of each river help establish an appropriate management plan for the river.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.542-550
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• 2017

The estimations of flow characteristics and river-bed erosion or sedimentation are very important for hydraulic structure design, floodplain management, and especially, river management. The objective of the study is therefore to estimate the change of flow characteristics and river-bed change due to a hydraulic structure construction. With 11.65 km study area of the Geum River which are located in downstream of Daecheong Dam, flow characteristics and river-bed change were estimated based on the RMA2 and SED2D model. As the result of the study, the increase of river-bed sedimentation in upstream and river-bed erosion in downstream were occurred by the construction of hydraulic structure.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.1
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• pp.67-75
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• 2011

The purpose of this study is to evaluate the flow duration characteristics of Nakdong, Seomjin and Geum river due to environmental change. The water level gauging stations of Nakdong, Seomjin and Geum river were selected to analyze the change of flow duration. The construction period of multipurpose dam was considered to analyze flow duration characteristics. As the result of this study, it show that ninety-five day flow, normal flow, low flow and drought flow were increased by multipurpose dam construction at all stations except a Jukpo gauging station. Especially, improved effect of flow duration in downstream part was bigger than that in upstream and midstream part. The coefficients of river regime of Nakdong, Seomjin and Geum river were decreased and also coefficients of flow duration were decreased after the multipurpose dam construction. However decline of coefficient of flow duration was smaller than coefficient of river regime because coefficient of flow duration is less affected by maximum discharge and minimum discharge than coefficient of river regime, It was confirmed that multipurpose dam on upstream and midstream has a useful effect for improving the flow duration characteristics.

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.51-55
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• 2001

The pollution characteristics of water quality analysis and the heavy metal analysis of river sediment in the Western Nakdong river, and then a commercial tile using the polluted sediment was produced. The analytical results of the riverbed structure and the depth distribution in the Western Nakdong river were that Macdo Stream(site 2) was the deepest(13 ft). The analytical result of water quality showed that BOD was the highest in the Hogei Stream(site 6); COD, Syanduengchi Island(site 1);SS, Macdo Stream(site 2);T-N, Suanduengchi Island(site 1);T-P, Macdo Stream(site 2). Therefore the deeper the site was the higher the pollution concentration was. The result of heavy metal analysis of the river sediment was that Pb and Cr were the highest in Kangdong Bridge(site 9); Cd, Macdo Stream(site 2), so the deeper the site was the higher the pollution concentration was. The production of tile using the mixure of the polluted sediment and the raw material was successful, so the reuse of polluted sediment was possible.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.4
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• pp.1-7
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• 2019

Cooling using the Han River has recently been spreading. The Ministry of Trade, Industry and Energy submitted a revised enforcement ordinance to include river water in renewable energy. Therefore, it is necessary to analyze the water temperature characteristics of Han River. Especially, it is necessary to investigate the effect on hot summer. In this study, we analyzed the water temperature of the last 11 years. It is intended to utilize the Han River for building cooling in the future.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.889-896
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• 2007

From the direct outflow of Chungju Dam to the junction of water body and watershed in Paldang lake is the scope of this research. This study performed to investigate the main cause of water quality deterioration and the influenced region in the middle field range of the Namhan river Basin with the onsite measurement of water quality and flow rate simultaneously during spring dry season. The purpose of this study is to find out the time-spatial variation characteristics of water quality and flow rate. Following the flow direction $BOD_5$ and $COD_{Mn}$ concentration increased to the highest value of 3.7 mg/L, 5.9 mg/L at Wolgesa respectively. Chl.a concentration increased to $50mg/m^3$ or so at Kangsang, after that it decreased to $37mg/m^3$ at the junction of Paldang lake. Organic matter concentration variation trend showed similar than that of Chl.a. Also $BOD_5$ concentration tendency was similar to Chl.a in every measuring sites except Paldang lake mixing zone. The major factors of water quality deterioration in Namhan river and Paldang lake during dry season were algal bloom and followed internal production. High phosphorus load from Dalcheon and Seom river caused dry season algal bloom and internal production in transitional zone which was stagnant area in downstream of Namhan river.