• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.40-49
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• 1997

From water management point of view, the industrialization that we have achieved in the last decades brought out two major changes: water shortage and water quality deterioration. They are getting the big obstacles we must overcome to continuously pursue industrialization for further development in the next century. Many plans using dams and advanced treatment methods have been developed for control of quantity and quality, respectively. In this paper, an alternative is conceptually reviewed which is much different from the plans in regard that the alternative looks at system itself. It is based on an interceptor system coupling with a concept of zero-discharge. This system allows no discharge of wastewaters from point-sources to waterbodies which are very sensitive in terms of water quality. In addition reuse of treated effluents is emphasized to a maximum extent. The application of the system to the Nak-Dong river basin indicated that an interceptor system will need from the middle reaches of the basin where industrialization gets heavier. Since wastewaters are not directly discharged to the river, water quality of the down stream will improve. Treated effluents will be able to be reused at a number of industrial complex which currently get water from the Nak-Dong river. This reuse will help alleviate water shortage. The biggest problem anticipated is cost for building and operating such system. A cost-sharing plan among the beneficiaries is considered. Further research is suggested focusing on detailed engineering and technical matters for potential implementation.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.107-118
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• 2001

This study was to develop a tow-dimensional model system for the hydrodynamic analysis and to apply the system on the downstream of Han River. it is performed to design a GIS-based hydrodynamic system for the scientific shallow water profile analysis, and to compare hydrodraulic modeling is the Petrov-Galerkin's finite element method for flow prediction model. This study was to construct a GIS-based river flow system, and it is useful for supporting user's decision making for the on-line status through various analysis. We expect that the results from this study can be used as one of the guidelines for river analysis and management system in order rivers, reservoirs, and estuaries.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.472-477
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• 2006

This study aims at investigating the failure cases of the pre-cast block system in river environments which widely used nowadays and reviewing the effect and flow resistance for grass concrete structure through the physical experiments by hydraulic model test and developing application method in river slope or levee which has rigid flood resistance. Grass concrete structure has been independently tested under high velocity flow under the super critical condition, it survived the 8 m/sec maximum flow velocity. This results shows grass concrete system is also suited to use in aggressive river environments such as repairing a flood damaged embankment that had placed at risk the adjacent drainage channel with vegetation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.203-206
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• 2001

Finding the optimal solution in the river water quality management system is very hard with the non-linearity of the water quality model. Many suggested methods for that using the linear programming, non-linear programming and dynamic programming, are failed to give an optimal solution of sufficient accuracy and satisfaction. We studied a method to find a solution optimizing the river water quality management in the aspect of the efficiency and the cost of the waste water treatment facilities satisfying the water Quality goals. In the suggested method, we use the QUAL2E water quality model and the genetic algorithm. A brief result of the project to optimize the water quality management in the Youngsan river is presented.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.619-625
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• 2006

Amount of soil loss is important information for the proper water quality management, In this research, annual average soil loss of the Geum River basin was estimated using RUSLE (Revised Universal Soil Loss Equation) and GIS (Geographic Information System). Input data were manipulated using ArcGIS ver. 8.3. From crop field which constitute 8.2% of the Geum River Basin, annual average soil loss was estimated as 53.6 ton/ha/year. From the rice paddy field which constitutes 20% of the Geum River Basin, soil loss was estimated as 33.5 ton/ha/year, In comparison, forestry area which constitutes 61.8% of the basin discharged 2.8 ton/ha/year, It could be known from this research that appropriate measures should be implemented to prevent excessive soil loss from the agricultural areas.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.497-502
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• 2017

하천의 수리 정보는 여러 가지 하천 사업 수행에 기본 자료로서 매우 중요한 역할을 한다. 하지만 우리나라의 하천 수리 정보는 대하천 중심으로 조사되고 있고, 중 소하천에 대한 수문조사는 상대적으로 매우 미진한 실정이다. 본 연구의 목적은 중 소하천에 대하여 정확도 높은 수리 정보를 저비용, 실시간으로 취득하기 위한 시스템을 개발하는데 있다. 이를 위해 하천의 수면을 촬영하여 촬영된 영상을 실시간으로 서버로 자동전송하는 시스템인 WIA 시스템(wireless image acquisition system)을 개발하였다. 그리고 촬영된 영상을 분석하여 수위를 도출하는 영상 분석 프로그램, 수위-유량 관계 곡선(rating curve), 미계측 지점에 대한 하천수리 정보를 계산하기 위한 HEC-RAS를 포함하는 River-HQ 시스템을 개발하였다. 개발된 WIA & River-HQ 시스템은 한국건설기술연구원의 하천실험센터 내 직선 수로에서 검증되었다. 그 결과, 영상 분석에 의한 수위는 계측 수위와 유사하였고, 미 계측 단면에 대한 수위 역시 계측 결과를 비교적 잘 모사하였다.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.317-325
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• 2010

This study was to investigate phytoplankton communities and to evaluate the effects of hydrological and physical-chemical environmental factors in major five dam reservoirs in the Han River water system. Annual average of chlorophyll a concentration in Lake Paldang, Lake Cheongpyeong and Lake Doam was higher than that of Lake Chungju and Lake Hoengseong. The opposite seasonal variation patterns of phytoplankton growth were observed in dam reservoirs; the highest biomass in spring of dry season in Lake Paldang, Lake Cheongpyeong which are the river-type reservoirs and Lake Doam where turbidity was high throughout the year, and in summer and autumn of rainy season in Lake Chungju and Lake Hoengseong which are the lake-type reservoirs, indicating that the seasonal pattern for growth of phytoplankton in on-river reservoirs is mainly determined by hydrologic characteristics. The dominant species of phytoplankton in Lake Paldang, Lake Cheongpyeong and Lake Doam, where the concentration of nutrients was relatively high, were Bacillariophyceae such as Stephanodiscus hantzschii, Aulacoseira granulata var. angustissima in Lake Paldang and Lake Cyeongpyeong and Nitzschia spp. in Lake Doam throughout all season. The dominant species of phytoplankton in Lake Chungju and Lake Hoengseong which showed the oligo-mesotrophic state, were Bacillariophyceae such as Stephanodiscus hantzschii, Cyclotella pseudostelligera in spring and winter, but Cyanophyceae such as Microcystis spp. in summer.

• Journal of Korea Water Resources Association
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• v.38 no.6 s.155
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• pp.471-483
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• 2005

A monthly Ensemble Streamflow Prediction (ESP) system was developed by applying a daily rainfall-runoff model known as the Streamflow Synthesis and Reservoir Regulation (SSARR) model to the Han, Nakdong, and Seomjin River basins in Korea. This study first assesses the accuracy of the averaged monthly runoffs simulated by SSARR for the 3 basins and proposes some improvements. The study found that the SSARR modeling of the Han and Nakdong River basins tended to significantly underestimate the actual runoff levels and the modeling of the Seomjin River basinshowed a large error variance. However, by implementing optimal linear correction (OLC), the accuracy of the SSARR model was considerably improved in predicting averaged monthly runoffs of the Han and Nakdong River basins. This improvement was not seen in the modeling of the Seomjin River basin. In addition, the ESP system was applied to forecast probabilistic runoff forecasts one month in advance for the 3 river basins from 1998 to 2003. Considerably improvement was also achieved with OLC in probabilistic forecasting accuracy for the Han and Nakdong River basins, but not in that of the Seomjin River basin.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.211-211
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• 2015

Mekong River is the world's $10^{th}$ longest river and runs through China's Yunnan province, Burma, Thailand, Laos, Cambodia and Vietnam. And Tonle Sap Lake, the largest fresh water body in Southeast Asia and the heart of Mekong River system, covers an area $2,500-3,000Km^2$ in dry season and $10,000-16,000Km^2$ in wet season. As previously noted, the water within Sap river flows from the Mekong River to Tonle Sap Lake in flood season (between June and October) and backward to Mekong River in dry season. Recently the flow regime of Sap River might be significantly affected by the development of large dams in upstream region of Mekong River. This paper aims at basic study about the large scale flood inundation of Cambodia using by CAESAR-Lisflood. CAESAR-Lisflood is a geomorphologic / Landscape evolution model that combines the Lisflood-FP 2d hydrodynamic flow model (Bates et al, 2010) with the CAESAR geomorphic model to simulate flow hydrograph and erosion/deposition in river catchments and reaches over time scales from hours to 1000's of years. This model is based on the simplified full Saint-Venant Equation so that it can simulate the interacted flow of between Mekong River and Tonle Sap Lake especially focusing on the flow direction change of Sap River by season.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.2193-2196
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• 2008

In this study, the new methodology such as support vector machines neural networks model (SVM-NNM) using the statistical learning theory is introduced to forecast flood stage in Nakdong river, Republic of Korea. The SVM-NNM in hydrologic time series forecasting is relatively new, and it is more problematic in comparison with classification. And, the multilayer perceptron neural networks model (MLP-NNM) is introduced as the reference neural networks model to compare the performance of SVM-NNM. And, for the performances of the neural networks models, they are composed of training, cross validation, and testing data, respectively. From this research, we evaluate the impact of the SVM-NNM and the MLP-NNM for the forecasting of the hydrologic time series in Nakdong river. Furthermore, we can suggest the new methodology to forecast the flood stage and construct the optimal forecasting system in Nakdong river, Republic of Korea.