• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.110-117
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• 2005

This paper deals the shaking table tests with 1/100 scaled model followed by Scott & Iai(1989)'s similitude law for OO dam main desging section to understand nonlinear behavior characteristics of concrete dam body by earthquake wave. As earthquake wave, Hachinohe and Elcentro waves were used and acceleration and displacements are measured to analyze behaviors of dam body. For ground maximum acceleration range ($0.3^{\sim}0.9g$), the results showed linear behavior regardless of ground maximum acceleration and secured safety of structure. To analyze the behavior of dam after tension cracking, 3cm-notch was placed at the critical section of over-flowing section. As results of applying Hachinohe wave(0.8g), Even though tension cracks were formed at over-flowing section by Hachinohe wave(0.8g), it showed that the dam is stable for supporting upper stream part of water tank of dam.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.7 s.100
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• pp.806-812
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• 2005

This paper adresses the shaking table tests with 1/100 scaled model followed similitude law for OOdam main designing section to understand nonlinear behavior characteristics of concrete dam body by ground motion. As earthquake wave, Hachinohe and El Centre waves were used and acceleration and displacements are measured to analyze behaviors of dam body. For maximum ground acceleration range $(0.3\~0.9 g)$, the results showed linear behavior regardless of maximum 9round acceleration and secured safety of structure. To analyze the behavior of dam after tension cracking, 3 cm-notch was placed at the critical section of over-flowing section. As results of applying Hachinohe wave(0.8 g), Even though tension cracks were formed at over-flowing section by Hachinohe wave(0.8 g), it showed that the dam is stable for supporting upper stream Part of water tank of dam.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.678-687
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• 2018

The purpose of this study was to understand the unique and complicated feature of urban stream receiving various inflows. The Yangjae stream, the second tier of the Han River, runs through the southern parts of Seoul, Korea and its middle part flows on the boundary of Seoul where land use is actively changing. Stream flow was greatly influenced by rainfall. Other than rainfall events, effluent discharge from wastewater treatment plant (WWTP) comprised 51 % of stream flux. As a result, majority ions water chemistry was changed at the receiving zone of the discharged effluent (Zone A). Its contribution increased to 69.9 % at the second sampling period with low stream flow. In the middle zone, inflows from the northern area, recently developed to a residential district showed low $NO_3-N$ and high $HCO_3$, Ca, $SO_4$, and $SiO_2$ indicating the effects of groundwater and concrete. One inflow (T-8), with extremely high Na and Cl, median $SiO_2$, was assessed to have anthropogenic influence, however its contribution to main stream was under 1 %. Road construction near Y-13 also affected water chemistry leading to the highest Na and Cl concentration. These hydro chemical changes can be critically used to evaluate the changes in water budget and fate of chemicals in a peri-urban watershed occasioned by human activities on the Yangjae.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.30-36
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• 2002

A 0.19 hectare natural-type wetland for stream water treatment demonstration was constructed and planted with cattails from April 2001 to May 2001. Part of its bottom surfaces adjacent to levees have a variety of slope of 1 : 4~1 : 15. Two small open water areas were installed, in which emergent plants could not grow. Removal of nutrients from stream waters was a major objective of the wetland. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped and funneled into the wetland. The lake had been formed by a salt marsh reclamation project and was located southern coastal region of Korean Peninsula. Volumes and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged $120.4m^3/day$ and $112.1m^3/day$, respectively. Hydraulic retention time was about 3.1 days. Average total phosphorous concentration of influent and effluent was $0.19mg/{\ell}$ and $0.075mg/{\ell}$, respectively. Total phosphorous loading rate of inflow and outflow averaged $12.05mg\;m^{-2}\;day^{-1}$ and $4.44mg\;m^{-2}\;day^{-1}$, respectively. Average total phosphorous removal rate in the wetland was $7.61mg\;m^{-2}\;day^{-1}$. Seasonal changes of phosphorous retention rates were observed. The wetland acted as effective phosphorous sinks in the initial stage of the constructed wetland.

• Economic and Environmental Geology
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• v.48 no.5
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• pp.409-420
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• 2015

The Sangdae-ri riverside around Musimcheon stream, flowing through Gadeok-myon of Cheongju City, is one of the representative strawberry fields employing water curtain cultivation (WCC) in Korea. In this area, annual groundwater use for WCC has been calculated by a few methods. On the assumption that all the water flowing through the final ditch may be mostly composed of groundwater, the discharge rate in it can be used as a good proxy for assessing the groundwater use. However, in the study area, the final ditch was set up in an unpaved state near and parallel to Musimcheon stream. Under such circumstances, the drainwater is likely to be influenced by infiltration and/or inflow of nearby stream. Hence, we examined whether or not stream water has influenced water flowing out through the final ditch in respect of ion concentrations or field parameters such as T, pH and electrical conductivity (EC) values. The period of measuring field parameters and sample collection was from February 2012 through February 2015. The drainwater in the final ditch did not show the average quality of groundwater, but similar quality of stream water in respect of pH, EC, ion contents and water type. From this, it is suggested that measuring the flow rate of the final ditch should not be directly used for assessing groundwater use in the study area. In addition, because of its sensitivity to ambient temperature, water temperature proved not to be appropriate for estimating the interaction between ditch and stream. For accuracy, additional methods will be needed to calculate mixing ratios between stream and ground water within drainage system.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.259-281
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• 2013

This research aims to analyze Baekdu mountain are with it's the east flowing streams which are the issues on the old maps. Also, it will analyze the eastern flows, Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. Also, it will analyze the north-eastern flows, Heukryong river; Songhwa river; Sockpyung river; Tomoon river; Boongye river; Dooman river, from Baekdu mountain which have been the border settlement issues since Josun dynasty. The mainly issued Baekdu mountain's north-eastern flows can be classified into six different flows by the classifications, it proves that there are various Baekdu mountain north-eastern flows on the old maps. the two streams theory of Tomoon and Doman river explains the perspective of the northern expansion, and the one stream theory expresses it by stating Boongye and Sockpyung river as the same one. However, in the case of the meaning of Boongye river is Haeran river on the middle of one stream theory map, there is no region expanding perspective but the same border perspective that Korean peninsula and China match. Boongye river is expressed into four different meanings. (1) It is the same river with Sockpyung and shows the regional expanding perception. (2) It is the same river with Tomoon and the down stream of Tomoon river.(3) It expresses the current name, Haeran river. (4) It simply means the river shows the boundary.

• Economic and Environmental Geology
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• v.51 no.6
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• pp.567-577
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• 2018

One of problems related with water curtain cultivation (WCC) in Korea includes severe declination of groundwater levels during the peak season, and it is likely that the problem can be resolved efficiently when the connection characteristics between groundwater and stream are well understood. This study examined temperature, and oxygen/hydrogen stable isotopic compositions of the flowing groundwater to understand the connection between stream and ground water, and the influence of stream water on the nearby aquifer. This study was performed in Wangjeon-ri (Kwangseok-myon, Nonsan City), the well-known strawberry town using WCC technique. The sampling was done during February 2010 through June 2011 for both groundwaters and nearby streams. Temperature distribution pattern indicates that stream widely affected groundwater in the right part of WCC ara. In the left part, the influence of stream seems to occur narrowly near the stream. The similar phenomenon is reflected in the oxygen and hydrogen isotopic data.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.83-93
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• 2004

The purpose of this study was to develop the environmental management strategy of streams based on the quantified evaluation method of the stream environment. The six streams in Jinju city flowing into the Nam-river were selected for the case study. The stream environment evaluation was performed considering the following three independent field surveys. First, the stream naturalnesses considering 20 evaluation elements were investigated for each unit section of the streams having the length of 500m and the width of 100m, and then were evaluated into 5 grades. Second, water qualities of the streams were evaluated into 5 grades based on the results of eight times water quality survey. Third, the landuse patterns in the stream basins were evaluated into 5 grades according to the residential area ratio. Finally, the stream environments were classified into 5 grades by integrating the above three subfactors - stream naturalness, water quality, and residential landuse. According to the evaluation results of stream environments, the three environmental management strategies of streams were suggested. As the results of the case study, Panmun stream and Ghajwa stream were evaluated to the forth grade that need active environmental restoration, and Nabul stream and Yonga stream were evaluated to the second grade that need partial environmental restoration while Youngchun river and Dogsan stream were evaluated to the first grade showing the desirable stream environmental condition. The above environmental evaluation results for each stream will be an important reference for the further stream restoration or management plan.

• Korean Journal of Environmental Biology
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• v.22
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• pp.71-77
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• 2004

Alkylphenols (8), chlorophenols (2), bisphenol A, eoprostanols (2) and cholesterol compounds were analyzed in the surface water and surface sediment taken from Gwangyang Bay and surrounding streams in 2001. Among the target analytes, nonylphenol and dihydrocholesteyol compounds were detected with high concentration and high frequency. t-Octylphenol, bisphenol A and coprostanols were detected only in some sediment samples from the stream. The highest concentration of nonylphenol was determined in stream sample, and concentrations of nonylphenol in the inner part of Gwangyang Bay were higher than those in the out part. Nonylphenol concentrations in the surface seawater and surface sediment samples ranged from 4.0 to 74.0 ng l$\^$-1/ and from 3.1 to 74.3 ng g$\^$-1/ dry wt., respectively. Partition coefficient (LogK$\_$oc/) of nonylphenol between sediment and water was 4.8. Nonylphenol nnd dihydrocholesteol concentrations in the stream surface sediment samples ranged from 4.6 to 808.6 and from 78.4 to 1133.6 ng g$\^$-1/ dry wt., respectively. Relatively high concentrations of nonylphenol were found in the stream samples which aye flowing through industrial complex area, while dihydrocholesterol concentration was relatively high in the stream samples which are flowing through only municipal area. Seaward decreasing tyend in nonylphenol concentration was observed from the Seomjin River estuary to the Gwanyang Bay. Such trend was best supported by the strong correlation between nonylphenol concentration and salinity in water samples.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.345-358
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• 1999

To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58％ of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.