• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.487-491
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• 2016

영산강 섬진강수계는 1999년 한강수계(경기도 7개 시군)에서 임의제로 도입한 이후 2002년 낙동강, 금강수계와 함께 의무제 기반으로 오염총량제를 추진하고 있다. 이에 따라 2004년부터 영산강물환경연구소에서 영산강 섬진강수계의 단위유역 말단 지점의 유량과 수질을 약 8일 간격으로 동시에 측정함으로서 단위유역 내 오염원으로부터 배출된 오염물질이 말단에서 실제 나타나는 오염부하량(유달부하량)의 파악이 가능하게 되었다. 그러나 최근 4대강사업으로 하천의 구조적 수질관리 환경의 커다란 변화가 있어 기존 모니터링지점에 대한 전면적인 재검토가 필요하게 되었다. 본 연구에서는 영산강 섬진강수계의 수질총량측정망 총 56개 지점을 대상으로 설치목적과 선정기준에 대한 적합성평가를 위한 평가기법을 공간적 대표성, 수리학적 안정성, 시간적 대표성, 정보취득 안정성의 4개 특성과 13개 평가부문, 20개 평가항목으로 3단계 평가기법으로 구성하여 개발하였으며 평가 결과, I등급이 29개소(53%), II등급이 25개소(45%), III등급이 2개소(3%)로 평가되었으며, 변경 및 폐쇄 권장에 해당하는 IV~V등급으로 평가된 지점은 없는 것으로 평가되어 대체로 우수한 지점들로 구성되어 있음을 확인하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.492-496
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• 2016

최근 4대강사업과 수질오염총량제 시행으로 하천의 구조적 및 비구조적 수질관리 환경의 커다란 변화에 따라 기존 모니터링지점에 대한 전면적인 재검토가 필요하다. 선정기준을 기반으로 평가기법은 공간적 대표성, 수리학적 안정성, 생태적 대표성, 시간적 대표성, 정보취득 안정성으로 5개의 특성과 14개의 평가부문 그리고, 평가항목으로 3단계 평가기법을 구성하여 개발하였다. 영산강 섬진강수계의 제주도수계 4개 중권역을 제외한 28개의 중권역을 대상으로 기존의 중권역 대표지점에 대하여 평가기법을 적용하여 그 적합성 평가를 실시하였다. 그 결과, 1등급이 8개 지점으로 29%, 2등급이 9개 지점으로 32%, 3등급이 6개 지점으로 21%, 4등급이 4개 지점으로 14%, 5등급은 1개 지점으로 4%를 차지하는 것으로 평가되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.247-247
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• 2020

생태유량은 하천에 서식하는 동·식물 등의 서식처 조건을 고려하여 갈수시에도 최소한의 하천생태계가 유지될 수 있도록 하는 유량이다. 이는 하천의 적정유량으로 적용할 수 있는 생태적 기준의 하나이며 수생생물의 물리적 서식처 적합도를 이용하여 산정할 수 있다. 특히 하천 생태계의 먹이 사슬 상층부에 속하는 어류는 서식처의 물리적 조건에 민감하므로 적절한 유량을 보장해 주는 것이 중요하며, 이러한 이유로 생태유량 산정에 어류의 서식처 조건이 주로 이용된다. 본 연구에서는 다목적댐의 건설과 준설 및 매립 등으로 유황 변동과 하류 염해 피해 등에 의한 하구 생태계 변화 등을 겪고 있는 섬진강 수계를 대상으로 송정, 겸백, 화개 세 지점에 대해 생태유량을 산정하였다. 이 생태유량은 섬진강 수계에서는 직접 측정에 한계가 있어 금강에서 측정된 피라미의 서식처 적합도 지수를 이용하였고, 지점의 하상재료 및 환경 조건을 반영하여 PHABSIM을 이용하여 산정되었다. 그 결과 송정의 최적 생태유량은 8.5㎥/s, 겸백은 2.26㎥/s, 그리고 화개 지점은 36㎥/s로 산정되었다. PHABSIM을 이용한 생태유량 산정 값은 지점에 따라 다소 과대 추정되는 경향이 있기도 하지만, 섬진강 수계의 해수 침투 등에 의한 염해 피해 대책 마련 등을 위해서는 산정된 유지유량을 확보하기 위한 해결 방안이 제시되어야 할 것으로 판단된다.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.581-587
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• 2013

The amounts of carbon (C), nitrogen (N) and phosphorus (P) in relation to dry weight (D.W.) were measured in zooplankton from the large four rivers (Han R., Geum R., Yeongsan R. and Seomjin R.) during 2004~2008. The stoichiometry of total zooplankton in four river systems was highly variable. The ranges of average C, N and P-contents were $70{\sim}620mgC\;mg^{-1}$ D.W., $7.1{\sim}85.5{\mu}gN\;mg^{-1}$ D.W. and $2.5{\sim}7.4{\mu}gP\;mg^{-1}$ D.W., respectively. The mean C :N: P atomic ratios reflected large spatial differences. The C : P and N : P ratios of the zooplankton community ranged from 38 to 392 : 1 and from 4 to 65 : 1 in all sampling sites. Self-Organizing Map (SOM) was applied to the survey data, and the study sites were clearly classified into 3 clusters. Clustering was largely affected by the distribution pattern of C, N, P-contents, which is related with characteristics of river systems on the basis of stoichiometry.

• Analytical Science and Technology
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• v.25 no.5
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• pp.313-323
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• 2012

We have developed analysis method of PFCs in river water and sediment, and determined seven species of PFCs such as PFBS, PFHxS, PFOS, PFHpA, PFOA, PFNA and PFDA. Water and sediment samples were collected from 21 and 13 different sites along the Nakdong, Seomjin and Nam River, respectively. The water samples were pretreated with HLB cartridge and sediment samples were concentrated after extracted by sonication, and the levels of PFCs were determined by LC-MS/MS. The coefficient of determination ($R^2$) values of calibration curves were higher than 0.99. The method detection limits ranged 0.09~0.63 ng/L in water and 0.013~0.020 ng/g in sediment. The recovery rates of PFCs was found to be 74~98% for water and 87~111% for sediment. PFOA was the major species in water samples and followed by PFHpA and PFOS. In sediment, PFOA, PFOS and PFDA showed similar levels. Both water and sediment samples collected from the Nakdong River showed the highest concentrations of PFCs among the three rivers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.175-185
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• 2023

As drought risk increases due to climate change, various research works are underway around the world to respond to drought so as to minimize drought damage. In particular, in recent years, many studies are focused on analyzing regional patterns of drought in a comprehensive manner, however there is still insufficient to quantitatively identify drought-risk areas in a large river basin considering climate change in Korea. In this study, we calculated the Standardized Precipitation Index (SPI) and the Modified Standardized Precipitation Index (M_SPI) as representative meteorological drought index, and performed spatial autocorrelation analysis to identify the drought hotspot region under climate change scenarios of Representative Concentration Pathway (RCP) 4.5 and RCP 8.5. The SPI was calculated by estimating parameters for each observation station within the study area, whereas the M_SPI was calculated by estimating parameters for the entire study area. It is more reasonable to use the M_SPI for assessing meteorological drought from an overall perspective within the study area. When the M_SPI was used, long-term droughts showed drought hotspot areas clearly larger than short-term droughts. In addition, the drought hotspot area moved from the center of the Nakdong River basin to the Seomjin River basin over time. Especially, the moving patterns of the short-term/long-term drought were apparent under the RCP 4.5, whereas the moving patterns of the long-term drought were distinct under the RCP 8.5 scenarios.

• Journal of Korea Water Resources Association
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• v.55 no.4
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• pp.279-289
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• 2022

Since the frequency of heavy rainfall is increasing due to climate change, water levels in the river exceed past historical records. The rating-curve is to convert water level into flow dicscharge from the regression analysis of the water level and corresponding flow discharges. However, the rating-curve involves many uncertainties because of the limited data especially when observed water level exceed past historical water levels. In order to compensate for insufficient data and increase the accuracy of flow discharge data, this study estimates the flow discharge in the river computed mathematically using Monte Carlo simulation based on a 1D hydrodynamic numerical model. Based on the existing rating curve, a random combination of coefficients constituting the rating-curve creates a number of virtual rating curve. From the computed results of the hydrodynamic model, it is possible to estimate flow discharge which reproduces best fit to the observed water level. Based on the statistical evaluation of these samples, a method for mathematically estimating the water level and flow discharge of all cross sections is porposed. The proposed methodology is applied to the junction of Yochoen Stream in the Seomjin River. As a result, it is confirmed that the water level reproducibility was greatly improved. Also, the water level and flow discharge can be calculated mathematically when the proposed method is applied.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.17-33
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• 2011

This study summarizes the research history of fluvial terraces in Korea and examines the geomorphic properties of fluvial terraces in Korea based on the previous works. The research history of fluvial terraces in Korea can be divided into the three periods. The theories of fluvial terraces were spread by the early geomorphologists during the period of Japanese colonial era to mid-1980s. The dissertations on the fluvial terraces were intensively published during the late 1980s to 1990s and their discussions were the center of geomorphology researches in Korea. Since 2000s, the discussions have become more mature and researches have been quantitatively increased as the various methodologies have been developed. The fluvial terraces in Korea are mostly developed in the western and eastern parts of the Taebaek Mountains, upper and middle reaches of Han and Nakdong River, and in the western slopes of Sobaek Mountains, middle reaches of Namhan River, upper and middle reaches of Geum and Seomjin River. Along these rivers in actively uplifted areas, fluvial terraces with much higher altitude from riverbed are observable and incision rates are relatively high. In the sense of the formation ages, they have developed in not regular patterns by the climatic changes during the Quaternary, but in more complicated aspects by the environmental conditions such as climate, hydrology, geology and geomorphology in the specific drainage basins.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.243-255
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• 2014

This study was investigated to estimate the relations between benthic environments and benthic polychaetous community from April 2012 to February 2013. Twenty four stations were selected sequentially with Seomjin River Estuary from the northern part of Gwangyang Bay. The study area could be divided into three characteristic zones based on salinity, water temperature, dissolved oxygen and pH such as Saline Water Zone (SWZ), Brackish Water Zone (BWZ), and Fresh Water Zone (FWZ). Salinity was above 30.0 psu in SWZ, drastically decreased toward inland in BWZ, and nearly zero psu in FWZ. SWZ showed its specific environmental characters like that water temperature fluctuated with little seasonal change and DO showed the lowest values among three zones, and pH maintained as consistent value without seasonal fluctuation. In FWZ, on the other hand, water temperature showed high seasonal fluctuation, DO showed the highest values among three zones, and pH fluctuated greatly. In sedimentary environment, mud, sand and sand/gravel were found as dominant sedimentary deposits in SWZ, BWZ and FWZ, respectively. Organic matter content and AVS in surface sediment were high in SWZ, while Chl-a content high in FWZ. This study area showed a marked environmental difference between FWZ and SWZ as follows: FWZ has coarse sediment and low salinity, low organic matter content, low AVS in FWZ but SWZ has fine sediment and high salinity, high organic matter content and AVS. Species number and mean density of benthic polychaete community was highest in Saline Water Zone (SWZ), drastically decreased in Brackish Water Zone (BWZ), and lowest in Fresh Water Zone (FWZ). Dominant polychates above 5.0% of individual numbers were 6 taxa. Lumbrineris longifolia, Prionospio cirrifera, Tharyx sp. occurred as main dominant species of all study periods, and Hediste sp., Praxillella affinis, Tylorrhynchus sp. dominantly occurred at some seasons. Inhabiting areas of dominant species were separated characteristically. Representative species in SWZ were Lumbrineris longifolia, Tharyx sp., Mediomastus sp.. Wide-appearing species between SWZ and BWZ were Prionospio cirrifera, Heteromastus filiformis, Aricidea sp.. Characteristic species in FWZ were Tylorrhynchus sp. and Hediste sp.. As the results of cluster analysis and nMDS based on the species composition of polychaetous community, unique station groups were established in SWZ and FWZ. Stations in BWZ were sub-divided into several groups with season. Pearson's correlation analysis and PCA between benthic environments and ecological characteristics of polychaetous community showed that salinity, sediment composition, organic content and dissolved oxygen played a role to determine the temporal and spatial distribution of the ecological characteristics as species number, mean density, abundance of main species, and ecological indices.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.32-38
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• 2011

In this study, the correlations of concentrations in sediment heavy metals between two pretreatment methods, total digestion and aqua regia digestion, have been investigated. Total 43 samples had been collected from streams and lakes in Yeongsan and Seomjin watersheds. They were decomposed in two pretreatment methods and five metal components (Cd, Cr, Ni, Pb, Zn) were analyzed. Overall average concentrations of heavy metals were Zn>Cr>Pb>Ni>Cd in the order. The concentrations of aqua regia digestion were 35.0% (Cd), 53.8% (Cr), 66.2% (Ni), 64.4% (Pb) and 76.4% (Zn) of the concentrations of total digestion and heavy metal concentrations of total digestion were higher. Heavy metal concentrations in sediments from lakes were higher than those from streams. The correlation equations between the concentrations of total digestion and aqua regia digestion were obtained. The concentrations of Zn and Ni, which showed strong linear correlations, increased in aqua regia digestion as the concentration in total digestion increased. The linear correlation coefficients between two digestion methods for most analyzed metals were above the average correlation. However, these results can be applied with limitations due to heterogeneity of sediments.