• Journal of environmental and Sanitary engineering
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• v.10 no.1
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• pp.1-11
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• 1995

We had passed through a serious water pollution with a rapid urbanization and industrialization in the 1960's. Seoul Chunggyechun Sewage Disposal System set uP in 1966 and finished in 1976, as the first sewage disposal system in Korea, had covered only 4 percentage of the sewage disposal system per capita for 10 years. Through holding the Asian Games in 1986 and the Olympic Games in 1988, we expanded the sewage disposal system so that it became increased 18 percentage of the population in 1986. Finally, we have installed about 60 sewage disposal system by 1994 for a large environmental investment which was critically caused by "Phenol Accident in Nakdong River" . Now, the sewage disposal system per capita covers 42 percentage and the activity for water quality improvement is going on rapidly. The method of sewage disposal is mainly "activated sludge process" . However, the technical ability for the sewage disposal has largely developed since 1991 so the "extended aeration process" is used in Po$\v{u}$n, Tangyang, Mun$\v{u}$i, "rotating biological contact process" in Onch$\v{u}$ng, Pukok, and "oxidation ditch process" in K$\v{o}$ch'ana.

• International Journal of Contents
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• v.7 no.1
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• pp.45-51
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• 2011

To protect water pollution and scarcity in lake and river, water quality monitoring applications have become important tools to understand the change of aquatic ecosystem. KLEON (Korean Lake Ecological Observatory Network) is designed to manage and share the ecological observations. The various kinds of water quality and phytoplankton observations are collected from the selected observatories such as seven lakes/rivers/wetlands. To deeply understand the collected observations with weather, KLEON also manages the observatory information such as lake, dam, floodgate, and weather. The accumulated observation and analyzed results are used to improve the water quality index of the observatories and encourage the ecologists' cooperation.

• Journal of Environmental Impact Assessment
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• v.20 no.5
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• pp.765-777
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• 2011

According to the total pollution load management system, exact prediction and analysis of water quality and discharge has been required in order to allocate the amount of pollution load to each local government. In this study, QUAL2E model was used for comparison with other water quality models and improve the inadequate to forecast future water quality. And Various calibration and verification methods were applied to deal with existing uncertainties of parameter during modeling water quality. For user convenience, A GUI(Graphical User Interface) system named "QL2-XP" model is developed by object-oriented language for the user convenience and practical usage. Suggested GUI system consist of hydraulic analysis, water quality analysis, optimized model calibration processes, and postprocessing the simulation results. Therefore this model will be effectively utilized to manage practical and efficient water quality.

• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• Water for future
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• v.29 no.2
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• pp.167-178
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• 1996

In designing automatic water quality monitoring networks for a river basin, determination of measurement locations and items is critical to the effectiveness of the total system. In this paper we studied how to decide these two design factors when a monitoring network is designed for the purposse of water quality surveillance and emergency alarm. For measurement locations, candidate sites are chosen based on the intake amount for water supply and the point sources of contamination. Then, detailed locations are decided according to the contaminant flow distance. As for measurement items, characteristics and the accident history of water pollution in the basin must be taken into account. Considering economic aspects, we proposed a two-stage measurement plan: basic components for all locations and selective ones variable for different locations. Proposed methodology is demonstrated through a case study for Nak-dong River Basin.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.792-802
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• 2009

The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.77-88
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• 2008

There has been growing demands to manage the water quality of west coastal region due to the large scale urbanization along the coastal zone, the possibility of application of TMDL(Total Maximum Daily Loadings) to Han river, and the natural disaster such as oil spill incident in Taean, Chungnam. However, no system has been developed for such purposes. In this background, the demand of GIS based effective water quality management has been increased to monitor water quality environment and propose best management alternatives for Han river and Kyeonggi bay. This study mainly focused on the development of integrated water quality management system for Han river bas in and its estuary are a connected to Kyeonggi bay to support integrated water quality management and its plan. Integration was made based on GIS by spatial linking between water quality attributes and location information. A GIS DB was built to estimate the amount of generated and discharged water pollutants according to TMDL technical guide and it included input data to use two different water quality models--W ASP7 for Han river and EFDC for coastal area--to forecast water quality and to suggest BMP(Best management Practices). The results of BOD, TN, and TP from WASP7 were used as the input to run EFDC. Based on the study results, some critical areas which have relatively higher pollutant loadings were identified, and it was also identified that the locations discharging water pollutant loadings to river and seasonal factor affected water quality. And the relationship of water quality between river and its estuary area was quantitatively verified. The results showed that GIS based integrated system could be used as a tool for estimating status-quo of water quality and proposing economically effective BMPs to mitigate water pollution. Further studies need to be made for improving system's capabilities such as adding decision making function as well as cost-benefit analysis, etc. Also, the concrete methodology for water quality management using the system need to be developed.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.255-268
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• 2012

Nonpoint source pollution has become a concern for water quality in the Han River system, especially during the high runoff events during the monsoon season. The patterns in nonpoint source runoff the relationships with land use, rainfall intensity, and stream nutrients concentrations were surveyed in 19 streams in the Han River watershed. The results show that the magnitude of NPS inputs of nutrients and sediment in the Han River watershed are of a serious concern. In the South Han River watershed, event mean concentrations (EMC) for biochemical oxygen demand (BOD), suspended sediment (SS), dissolved organic carbon (DOC), dissolved total phosphorus (DTP), total nitrogen (TN) Nitrate ($NO_3$-N) and total phosphorus (TP) were $1.94mg{\cdot}L^{-1},\;251mg{\cdot}L^{-1},\;2.75mg{\cdot}L^{-1},\;0.076mg{\cdot}L^{-1},\;2.82mg{\cdot}L^{-1},\;2.40mg{\cdot}L^{-1}$ and $0.232mg{\cdot}L^{-1}$, respectively. In the North Han River watershed, EMCs for BOD, SS, DOC, DTP, TN, $NO_3$-N and TP were $1.34mg{\cdot}L^{-1},\;172mg{\cdot}L^{-1},\;2.63mg{\cdot}L^{-1},\;0.032mg{\cdot}L^{-1},\;1.97mg{\cdot}L^{-1},\;1.55mg{\cdot}L^{-1}$ and $0.148mg{\cdot}L^{-1}$, respectively. The specific export coefficients of nutrient and sediments were much higher than those of other reports. Our study also found that the proportion of agricultural field area was significantly correlated with the EMCs for nutrients. Therefore, efforts to reduce NPS loading must focus on agricultural practices in the watershed. The relationships between land use and nutrient and sediment export found in this study can be used to derive estimates of runoff coefficients for agricultural field and as input data for modeling works and to develop total maximum daily load and best management practices in the Han River watershed.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.206-212
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• 2012

2012년 상반기를 기점으로 '4대강 살리기 사업' 1 단계가 완료 되었다. 추후 안동댐과 임하댐의 연결 사업과 낙동강 상류 내성천의 영주 댐과 금호강 상류에 보현 댐 건설이 예정 되어 있지만, 낙동강 수계에는 8개 보 건설이 완료되어 하천의 물리적 환경이 바뀌었다. 따라서 앞으로는 보의 유지 및 운영 관리(주로 수질관리, 어도관리, 토사퇴적 및 세굴관리)가 중요하게 될 것이므로 기존의 상류 댐 운영 목표와 방식도 변해야 한다. 낙동강 수계는 11월부터 다음해 6월 까지가 갈수기에 해당한다. 따라서 갈수기에 수질을 담보할 유량이 실제로 흐를 수 있는지를 낙동강 유역 총체적인 관점에서 분석을 하고, 방류계획을 세울 필요가 있다. 수량이 수질을 항상 보장해 주지는 못하지만, 용수공급 목표를 저해할 환경과 생태계를 위한 무리한 초과 방류를 해야만 할 경우가 발생한다면, 그로 인한 기존의 농업, 공업 및 생활용수 공급에 미칠 영향을 가늠해서 대책을 세워야 한다. 본 연구에서는 좀 더 정교한 수질사고 시뮬레이션 모형, Water Pollution Accident Response Management System (WARMS)과, 하천수질예측시스템(Water Quality Forecasting System)모형 등, 수질을 고려한 3차원 모형과의 연동 및 연계를 염두에 두고, 시스템적 측면에서 수질과 수량을 한꺼번에 고려함으로써 궁극적으로 시간과 비용을 절약한다는 점에서 효율이 높을 것으로 생각되는 댐-보 연계운영을 위한 분석 방법을 제안한다.

• Journal of Korea Water Resources Association
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• v.40 no.3
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• pp.251-263
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• 2007

In this paper, we constructed the integrated watershed model system, SWAT-Nak Dong that include areal mean precipitaiton, runoff and water balance components in the Nak Dong river basins and with this model system we are capable of estimating streamflows for ungaged river stations and analyzing the variations of the streamflows. SWAT(Soil and Water Assessment Tool) is a conceptual, continous time model that was developed in the early 1990s to assist water resource managers in assessing the impact of management and climate on water supplies and non-point source pollution III watersheds and large river basins. Using the SWAT-Nak Dong system and various scenarios, we analyzed and evaluated the dams and water uses effects on the streamflows.