• Journal of Korea Water Resources Association
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• v.38 no.3 s.152
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• pp.245-257
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• 2005

The purpose of the present study is examining the changes of runoff characteristics and extracting hydrologic parameters by applying ModClark model on grid divided watershed. Bocheong stream basin in Geum River system, one of the representative watersheds of IHP projects, is selected. Hydrology-based topographical informations are calculated using GIS data in the HEC-GeoHMS V1.1 extension in Arcview 3.2. The ModClark model requires precipitation data in a gridded format. The gridded data must be recorded in the HEC Data Storage System file format. Therefore, kriging method was used to interpolate the point values to create a grid that gives each cell over the entire watershed a precipitation value. Hec-DSSVue program was used to create DSS file for the rain gage data. The completed HEC-HMS model was calibrated for use in simulating three measured storm events and cell size of 10000m, 5000m, 2000m, 1000m was chosen for the application. As the result of applying distributed rainfall-runoff model to analyze relatively good agreement for peak discharge, runoff volume and peak time.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.535-544
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• 2019

To elucidate the cause of Pyropia yezoensis discoloration, the characteristics of an aquaculture environment, as well as the morphology and cell structure of P. yezoensis thallus were examined from 2011 to 2014 in aquaculture farms of the Jeonbuk province. P. yezoensis discoloration did not occur in aquaculture farms at Gaeyado located in the Geum River Estuary but occurred in aquaculture farms of Seonyudo, Munyeodo, Biando, and Docheongri near the Saemangeum embankment in November 2011 and April and November 2014. The injured leaves showed discoloration and intracellular vacuole hypertrophy. During the study period, discoloration occurred at concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) below 5μM and 0.4μM, respectively. As a result, Pyropia discoloration was determined by low concentrations of DIN and DIP. DIN deficiency affects the early stage and low DIP concentration affects the end stage of aquaculture.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.13-21
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• 2008

This study conducted water quality projection of year 2010 in Miho stream of the Geum river basin by using GIS. Pollutant load data of corresponding tributary of the Miho stream is estimated based on the pollutant load of TMDL zone to simulate water quality of the Miho stream for BOD, TN, and TP. The pollutant load of the urban area such as Bochung and Musim stream basin is relatively high and the wastewater treatment plant of Chunju city directly affects the entire water quality of the target area. As a result, simulation result reveals that water treatment facility needs more refined treatment process for efficient water quality management. Also, to meet the target water quality of the Miho stream water quality simulation estimates the additional dilution flow by increasing irrigation water supplied from the Daechung dam through the Musim stream.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.233-244
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• 2015

Marine ecosystem modelling has become a more widely used decision-making tool in coastal ecosystem-based management. However, it is not trivial to develop a well calibrated/validated model with potential applicability and practicality because understanding ecological processes with complexities is a pre-requisite for developing robust ecosystem models and this accompanies a great deal of well coordinated efforts among field-going ecologists, laboratory scientists, modelers, stake-holders and managers. This report aims to provide a brief introduction on two different approaches in marine ecological models: deterministic (mechanistic) and stochastic (statistical) approach. We also included definitions, historical overview of past researches, case studies, and contextual suggestions for coastal management in Korea. A long list of references this report included in this study might be used as an introductory material for those who wish to enter ecosystem modelling field.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.433-441
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• 2016

Many large dams have been constructed for water supply, irrigation, flood control and hydropower in Korea for the last century. Meanwhile, recent studies indicated that the artificial reservoirs impounded by these dams are major sources of carbon dioxide (CO₂) to the atmosphere and relevant to global budget of green house gases. However, limited information is available on the seasonal variations of CO₂ evasion from the reservoirs located in the temperate monsoon regions including Korea. The objectives of this study were to estimate daily Net Atmospheric Flux (NAF) of CO₂ in Daecheong Reservoir located in Geum River basin of Korea, and analyze the influencing parameters that characterize the variation of NAF. Daily pH and alkalinity (Alk) data collected in wet year (2012) and dry year (2013) were used for estimating the NAFs in the reservoir. The dissolved inorganic carbon (DIC) was computed using the pH and Alk measurements supposing an equilibrium state among the carbonate species. The results showed seasonal variations of NAF; negative NAFs from May to October when the primary production of the reservoir increased with water temperature increase, while positive NAF for the rest of the period. Overall the reservoir acted as sources of CO₂ to the atmosphere. The estimated NAFs were 2,590 and 771 mg CO₂ m^-2d^-1 in 2012 and 2013, respectively, indicating that the NAFs vary a large extent for different hydrological years. Statistical analysis indicated that the NAFs are negatively correlated to pH, water temperature, and Chl-a concentration of the reservoir.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.69-75
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• 2013

Miscanthus has received wide attention as an option for biomass production in Korea, recently. New strain of giant miscanthus has been developed and was planted in two large trial sites (184 ha) in the lower reaches of the Geum River. To evaluate the susceptibility of the giant miscanthus as an bioenergy crop for the future, we investigated the influence of the giant miscanthus on the soil properties. The particle size, CEC, pH, EC, T-N, T-P, heavy metal total concentration, and heavy metal fractions of soil samples collected from abandoned field, 1 year old giant miscanthus field (1st Year GM), and 2 year old giant miscanthus field (2nd Year GM) at different depths of 0~15, 15~30, and 30~45 cm in April and August were analyzed. Results showed that the CEC and pH of the soil of the giant miscanthus field were lower than those of the soil of abandoned field. The EC of 2nd GM was lower than that of abandoned field, indicating that the giant miscanthus may facilitate soil desalination process. The organic and sulfide fraction and residual fraction of heavy metals in the giant miscanthus field was higher than in abandoned field, due to the low pH of the giant miscanthus field and the excretion of phytosiderophores by rhizome of the giant miscanthus. This study showed that the giant miscanthus can influence on the soil properties and further study for long term is needed to elucidate the interaction between the soil and the giant miscanthus.

• Korean Journal of Ichthyology
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• v.29 no.2
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• pp.94-100
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• 2017

Three pseudo-silver eels (PS1~PS3) were found by analysis of silvering index and biological characteristics of 454 eels, Anguilla japonica, collected from the 9 sites of Korean fresh and brackish waters from September 2014 to August 2015. Two specimens (PS1~PS2) from Lake Soyang and one (PS3) from Geum river estuary were identified as pseudo-silver eel showing a large difference between silvering index and GSI. The external morphology of the pseudo-silver eels were in S2 (late silver eel) stage, but they were classified into Y1 (yellow eel) and Y2 (late yellow eel) stage in GSI, Gut index, Eye index and Y2 stage in gonadal development and mean egg diameter.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.894-899
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• 2010

국가적 차원에서 물을 사용하고 통제하는 일은 국민의 생활에 큰 영향을 주고 있기 때문에 대부분의 나라들은 주어진 여건에 맞게 효율적으로 물을 사용하고 홍수와 가뭄으로부터 국민의 생명과 재산을 보호하기 위해 많은 일들을 하고 있다. 이와 같은 목적으로 우리나라에서는 국가유량측정망을 구축하여 2007년부터 국가적인 차원에서 유량측정을 수행하고 있다. 하지만 국가유량측정망의 경우 유량자료의 제공에 주 목적이 포함되어 있어 실제 유량자료만이 아닌 수위자료만의 목적으로 운영되고 있는 수위관측소에 대한 평가가 부족한 것이 현실이다. 본 연구에서는 치수, 이수, 환경 목적을 위한 유량측정 지점 뿐만아니라 재난, 댐, 유지유량 관리 등과 같은 추가적인 목적으로 수위자료를 활용하는 지점들에 대하여 하천의 최상류 지점에서 하구까지 모든 지점에 대한 신뢰성 있는 수위정보를 실시간으로 파악할 수 있는 수위관측망을 구축하는데 목적을 두었다. 이를 위하여 금강홍수통제소, 한국수자원공사, 환경부에서 운영하는 수위관측소를 대상으로 홍수예보, 홍수 통제시설, 재난관리, 수자원 관리 및 공급, 수리권 갈등, 수질 등과 같은 다중목적을 적용하여 기존 관측소를 활용 목적별로 평가 하여, 각 기관의 중복투자에 따른 손실을 최소화 하고, 최적의 장소에 수위관측망을 구축하는 것이다. 이와 같이 도시, 댐 저수지 운영, 산간 및 농촌 지역 등의 현재 운영되고 있는 수위관측소 현황을 파악 한 결과 국토해양부 91개소, 한국수자원공사 18개소, 지자체 35개소, 환경부 26개소를 운영하고 있으며, 이중 환경부와 중복으로 검토된 지점은 15개 지점으로 나타났다. 최종적으로 수위관측소 운영 목적 및 지형학적 검토를 통하여 수위관측망을 검토한 결과 금강 권역의 하천 재난, 운영, 유지를 위해서 103개소의 수위관측소가 필요한 것으로 평가 되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1555-1559
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• 2010

본 연구는 미래 물 관리를 위한 기후변화 대응방안 도출 연구의 사전연구로서 금강유역의 과거 기상 수문요소의 특성변화 분석을 수행하였다. 기상자료로 금강유역 기상관측소 8개소의 37개년(1973~2009)의 기온, 강수량, 상대습도 자료를 수집하였다. 하천수위자료는 수위자료와 수위-유량관계곡선의 신뢰성 문제, 이후 수행될 장기유출분석을 고려하여 최종적으로 공주, 규암 수위관측소의 36개년(1973~2008)의 자료를 이용하였고, 지하수위자료는 강우관측소와 근접하게 위치해 있으면서 과거 자료를 최대한 많이 보유하고 있는 6개 관측소의 10개년(1999~2008)의 자료를 이용하였다. 수집된 자료의 평균, 표준편차, 왜곡도, 변동계수를 산출하여 연 계절별로 수문기상인자의 경년변화를 파악한 결과 기상인자 중 강수량의 변동성이 가장 크게 나타나 경년별 변화가 큰 것으로 분석되었고 하천수위보다는 지하수위가 경년별 변동이 적은 것으로 분석되었다. 수문학적 지속성 분석을 위해 Run 검정, Turning Point 검정, Anderson Exact검정을 이용하여 시계열자료에 주기성이 있는지 분석한 결과 기온과 강수는 무작위성, 상대습도, 하천수위는 지속성을 가지는 인자로 분석되었고 지하수위는 관측소별, 기간별로 무작위성과 지속성이 혼재되어 있는 것으로 나타났다. 마지막으로 경향성 분석을 위해 단순 선형 회귀분석과 Mann-Kendall 검정을 이용하였다. 그 결과 기온은 연 계절 모두 증가경향이 나타났고, 강수량은 여름에만 증가경향이 나타났으며, 상대습도는 뚜렷한 감소경향을 보였다. 또한 하천수위는 감소경향이 나타났으며 지하수위는 유의수준 범위에서 경향성은 보이지 않았다. 본 연구의 결과는 기후변화로 인해 발생될 수 있는 수자원의 영향을 평가하고 미래 물 관리 적응기술 개발 및 계획 수립을 위한 자료로 활용될 수 있을 것으로 사료된다.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.25-39
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• 2012

This study was aimed to assess the effects of additional installation of two different types of weirs, one is a curtain-type weir and another is a submerged-type weir, on the control of algal growth in Daechung Reservoir. A two-dimensional(2D) coupled hydrodynamic and eutrophication model that can accommodate vertical movement of the curtain weir following the water surface variations was verified using field data obtained in two distinctive hydrological years; dry(2008) and wet(2010). The model adequately simulated the temporal and spatial variations of water temperature, nutrients and algal(Chl-a) concentrations during the periods. The effectiveness of curtain weir on the control of algal bloom was evaluated by applying the model to 2001(dry year) and 2010 assuming 6 different scenarios according to installation locations. The curtain weirs that already installed at 3, 5, 7 sites(scenario C-2) showed significant effect on the control of algal growth in the reservoir; the reduction rates of algal concentration were placed in the range of 7.5~31.5% and 9.1~44.9% for 2001 and 2010, respectively. However the simulation results revealed that additional installation of curtain weirs(scenario C-3~C-6) in the bay area (choosori) have marginal effect. The effectiveness of submerged weir was evaluated against 2010 assuming 7 different scenarios according to installation locations, but all scenarios(S-1~S-7) showed neglectable or negative effect on the control of algal growth.