• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1144-1150
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• 2006

Recently, as water pollution accidents in rivers have increased, there is an increased interest in water quality forecast with accurate simulation. QUAL2E model, widely used for water quality analysis, uses the same hydraulic characteristics, such as depth and velocity, in a reach. The flow of the river is changed by various hydraulic constructions or by topography in a real river channel. In this study, a hydraulic connection module is developed to consider flow variations of river channels in QUAL2E model. The module uses the simulations results of non-uniform flow of a 1-D hydraulic model such as DWOPER or HEC-RAS. The improved QUAL2E model with this module was applied to a downstream section of Paldang Dam on the Han River. The results show the variation of water quality very well in a reach where flowing vary abruptly, like the Jamsil submerged weir.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.229-234
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• 2011

Feasibility assessment for small hydropower plants using diversion weirs located in stream for agricultural purpose has been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the inflow caused from rainfall. And another model to predict hydrologic performance for small hydropower plants is established. Preliminary survey was performed identifying several candidate sites, and two sites were selected finally for actual site reconnaissance. During the course of site survey, generating capacity, construction and equipment cost, and payback through life time of each sites were calculated for economical feasibility analysis. The results of this study have estimated that the small hydropower plants using diversion weirs for agricultural purpose may offer better opportunities in future with increasing fuel cost and nation's energy policy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.3_4
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• pp.82-89
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• 1995

The efforts of formulation have been reviewed and the results of existing laboratory experiments are investigated in order to describe the contracted flow which occurs at the final closure of sea dike construction. The regional characteristics of contracted flow is analyzed by checking the drawdown curve, and Chezy's mean velocity equation is employed to estimate the discharge rate at the closure. Weir-type discharge equations are reviewed, which are derived from Bernoulli equation, and the problems of the equations are discussed. Chezy's mean velocity equation is considered to be widely and generally applicable, and the empirical factor introduced in Chezy's equation is named 'form drag factor' since it is primarily dependent on the form drag caused by the contraction of discharge area. Laboratory experiments were conducted mainly in order to investigate the variation of form drag factor against various parameters, and an empirical equation is developed for the estimation of form drag factor.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.4
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• pp.187-198
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• 2017

Dissolved and particulate organic carbon concentrations and fluxes were measured and estimated for the Yeongsan River during 2006~2015. The dissolved organic carbon (DOC) concentrations ranged from 2.49 to $4.39mg{\cdot}C/L$ with a variance of 30.1% (${\sigma}_x/\bar{x}$), and showed a simple correlation to algal bloom and precipitation. The particulate organic carbon (POC) concentrations had gradually decreased from 6.68 to $0.19mg{\cdot}C/L$ for 10 years, and changed definitely with weir construction in 2011. Based on the relationships between POC and suspended particulate matters and between POC and chlorophyll-a, we found out that the distinct variation of the origin and composition of POC was caused by stagnation and screening effect of the dammed river. The total organic carbon (TOC) concentrations dropped to 52.3% (from 8.26 to $3.94mg{\cdot}C/L$) as the POC concentrations diminished to more than 94.8% after weir construction, in which the DOC forms up to 90.9%. The fluxes of TOC, based on the relationship between the annual TOC concentration and the discharge of Yeongsan dike sluice, were $2.56{\sim}19.41{\times}10^9g{\cdot}C/yr$, and showed a great deal of variability in 2011. Since then the TOC flux dropped to $5.40{\times}10^9$ (2011~2015) from $14.54{\times}10^9g{\cdot}C/yr$ (2006~2010). These results suggest that the weirs trapped annually $1.83{\times}10^9g{\cdot}C$ on a river bed, but released in great levels of dissolved organic form at their exits.

• Ecology and Resilient Infrastructure
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• v.1 no.1
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• pp.8-18
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• 2014

This study analyzes characteristics of flow using 3 dimensional numerical model, Delft3D, at the downstream of hydraulic structure. And fish shelters are suggested by analyzing them in flood time. A hydraulic structure changes flow conveyance, water depth and velocity affecting the activity of the fish. Flow depth decreases and velocity is fast near the left bank at the downstream of Gumi weir because of the concentration of flow due to it. Therefore, fish shelters are generated near the right bank of it. As a result of vertical velocity distribution which indicates the range of fish activity, maximum value are 0.0043 m/s in 30-year of return period of flood 0.0052 m/s in 50 year flood, 0.0046 m/s in 80-year of return period of flood, and 0.0039 m/s in 100-year of return period of flood. As the discharge increases, the areas of fish shelters decreases because depth and turbulent energy increase according to increases discharge. The estimated areas of fish shelters near the right bank decrease from 61.5% in 30-year of return period of flood to 39.0% 100-year of return period of flood. Therefore, the constructed hydraulic structures affect fish shelters.

• Journal of the Korean association of regional geographers
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• v.14 no.4
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• pp.279-289
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• 2008

The purpose of this paper is to search for geomorphological landscape resources of Goryeong-gun, to provide fundamental data for their management through mapping their distribution, and to present their conservation and application plan. The results are as follow: Firstly, geomorphological landscape resources in mountain area are Misungsan and Jusan mountain of Goryeong-up, Sangbiri valley of Deoggok-myeon, and isolated hill of Gaejin-myeon. Secondly, geomorphological landscape resources in riparian area are natural wetlands such as Jinchonneup of Bu-ri Gaejin-myeon, Hochonneup and Dalseongseupji of Hochon-ri Dasan-myeon, Bongsanneup of Bongsan-ri Ugok- myeon; artificial wetlands following the construction of weir such as riparian wetland of Oe-ri Goryeong-up and Banun-ri Gaejin-myeon; meander core and abandoned channel of Banun-ri Gaejin -myeon, river cliffs such as Naegok-ri Goryeong-up and Weolo-ri Ugok-myeon; sand bars and braided channel of Yajeong-ri Ugok-myeon. Thirdly, Jinchonneup swamp area of Bu-ri Gaejin-myeon have characteristics of typical floodplain landform, and its conservation conditions is relatively satisfactory, and its accessibility to metropolis is great, so it is a good place to construct eco-park. And construction of inquiry learning place at Banun-ri Gaejin-myeon will increase the opportunity to observe environmental changes following incised meander cutoff and ecological affirmative functions of a weir.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5801-5812
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• 2014

The retention basin is a hydraulic structure for flood mitigation by storing river flow over a design flood. In this study, numerical models were adopted to simulate the flood mitigation effects by a retention basin. The large flood condition was applied as a boundary condition to consider an abnormal flood caused by climate change. Furthermore, the two-dimensional numerical model was adopted to regenerate the complex flow pattern due to the topography and lateral flow near the retention basin. The numerical results of the one- and two-dimensional model were analyzed and compared. The results showed that the two-dimensional model is more applicable to assessing flood mitigation by the retention basin with a complex topography and lateral flow patterns.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.470-478
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• 2017

This study was classified into two groups, normal season group and drought season group, by the cluster analysis using the weather and water quality data from 2012 to 2015, using SPSS 18 version. Also each cluster was classified into three spaces, Gangcheon, Yeoju and Ipoh weir. We performed the multiple regression analysis with each monthly data that concentration of Chl-a was more than algae warming level. 6 groups classified in time and space were analyzed by the correlation analysis between concentration of Chl-a and 3 weather, 11 water quality and discharge factors. We developed Chl-a prediction equations of each group with independent variables of the multiple regression analysis applying to the correlation result. The result of cluster analysis was that the period was divided into two groups, normal group(2012-2013) that total annual precipitation rate was normal and drought group(2014-2015) that total annual precipitation rate was less than 1,000 mm/hr, in time. The months that concentration of Chl-a was more than algae warming level in each group classified by cluster analysis were that the normal group was 3~8 and drought group was 3 and 6~10. The correlation result between Chl-a and weather, water quality and discharge factors for each 6 group was that relationships between Chl-a and water, discharge factors were high in the drought group more than in normal group at all weirs. This was influenced by velocity reduction and increasing HRT according to the intense drought. Weather, water quality and discharge factors that were high correlation with Chl-a were applied to independent variables of Chl-a prediction equations and each equations were developed. Among them, Each adjusted R square of Prediction equations for Chl-a in each group at Ipoh weir where is located in Namhan river downstream and is directly connected to Paldang dam were normal group = 0.920 and drought group = 0.818. It's showed the high linear.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.205-205
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• 2011

우리나라의 중소하천에는 하상경사 조정과 농업용수 확보 등의 목적으로 많은 보가 설치되어 있다. 하천에 보를 설치하면 보를 기준으로 상 하류의 흐름특성이 변하고, 홍수시 소통이 원활하지 않아서 제방이 붕괴되는 등의 피해를 발생시킨다. 또한 유입유사의 흐름을 차단하여 상류단에 퇴적이, 하류단에는 침식을 발생시켜 하상변동이 일어나게 된다. 하상변동은 단기적으로는 하천에서의 취수, 배수와 주운 등 하천관리에 직접적인 영향을 주고, 장기적인 면에서는 하천 시설물의 안정, 홍수위 및 지하수위의 변화, 하천부지의 변화 등 하천 및 유역관리에 광범위한 영향을 주고 있다. 따라서 하천의 유황 및 하상재료의 인위적인 변화에 의한 하상변동을 예측하고 분석하는 것은 하천계획 및 운용 관리면에서 매우 중요하다. 본 연구는 경안천 유역에 설치된 보를 대상으로 설치 전의 지형자료 및 수리학적 자료를 이용하여 모델링을 하였고, 이를 토대로 설치 후의 수리학적 특성 및 하상변동을 분석하였다. 모델링은 종 횡단으로 모의할 수 있는 2차원 유한요소모형인 RMA-2를 이용하여 보를 설치하기 전 후의 수위, 유속 등의 흐름특성을 모의하였고, SED-2D를 이용하여 하상변동 특성을 비교 분석하고자 하였다. 그 결과 경안천 유역에 설치된 보로 인해 보의 상류단에서는 수위가 상승하고 유속이 감소하는 경향을 나타내고, 유사의 퇴적으로 인해 하상 상승이 발생하였다. 또한 보의 하류단에서는 보월류시 유속이 증가하여 수위가 하강하는 흐름특성을 보였고 침식이 발생하였다.

• The Journal of Korean Medicine
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• v.28 no.1 s.69
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• pp.42-50
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• 2007

Objectives . This study was to assess the Korean Traditional Medicine forecast subjects that had been expected to be accomplished by 2005. The result will help the Korean medical society plan far policies and studies on Korean Traditional Medicine. Methods : Assessed targets were 64 subjects (expected to be studied until 2005) of the total 93 subjects from the 'Mid- to Long-Term Forecast and Plan Study for Korean Traditional Medicine'. The subjects were classified into two types : political subjects and research and development (R&D) subjects. These were determined by the quantity and contents of related political reports, political research projects, thesis, patent, placing products on sale, etc. Results :1) 5 items of a total 12 political subjects were accomplished or partially accomplished (41.7%), and 9 items of a total 46 R&D subjects were accomplished or partially accomplished (9.5%). 2) While the accomplishment percentage (accomplished or partial accomplished) in literature arrangement and D/B construction field was 100%, it was under 10% in product or system development field. Thus, it seems that practical subjects were less accomplished than academic subjects. 3) On 8 subjects of 'Forecast Research on Future of Oriental Medicine' which had been performed in Japan, the Korean expected dates when the subjects would be realized were earlier than the Japanese ones, but no subjects were realized. Conclusion · Political and academic subjects weir accomplished more than R&D and practical subjects.