• Korean Journal of Environmental Agriculture
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• v.25 no.2
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• pp.138-146
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• 2006

To understand the status of water quality and work out a suitable countermeasures in Seonakdong watershed which has poor agro- environmental condition because of severe point and non-point source pollution by popularized city and near sea, we investigated the pollution sources and water quality from '03 and '05 and the result were mapped with GIS and RS for end-users's convenient comprehense and conjunction of water quality and geological data. The most degraded tributary was Hogeo stream which was affected directly by highly popularized Gimhae city, the main pollution source of the watershed. The pollution of tributaries in watershed increased the T-N of main body that reached over 4 mg/L during dry season. Pyeonggang stream and the lower part of main water way were suffered from high salt contents induced near sea and the EC value of those area were increased to 2.25 dS/m. The delivered loads of T-N and T-P were largest in Joman river as 56% and 61% of total delivered loads 1mm tributaries because of lots of stream flow. When Management mandate for irrigation water in Seonakdong river watershed was mapped for estimating integrated water quality as the basis of classification of EC and T-N contents in water, Hogeo and Shineo catchments were showed the requiring countermeasures none against nutrients hazard and Pyeonggang catchment was the vulnerable zone against nutrients and salts hazard. As the result, Seonakdong watershed had very various status of water quality by characteristics of catchments and countermeasures for improving water quality and crop productivity safely should changed depend on that.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1021-1030
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• 2022

Currently, South Korea implements water resources management policies focusing on integrated water quantity, quality and hydro-ecology management. In particular, rehabilitation of natural rivers has become a major issue. As for reservoir operation during non-flood season, efforts have been made continuously to apply the Deficit Supply Method that can maximize water supply to address droughts and increase in water demand. When Deficit Supply Method is applied, the water supply capacity of reservoir can be maximized. However, downstream water flow would remain constant. In consideration that a natural stream, a long-time-created hydro-ecology, can be significantly influenced by flow variability, the Deficit Supply Method-based reservoir operation can generate effective water supply. Still, it may trigger adverse effects from the aspects of natural rehabilitation and hydro-ecology recovery. The main objective of this study is to analyze impacts on downstream flow duration through reservoir simulation by comparing the Firm Supply Method, the Deficit Supply Method and the Selective Deficit Supply Method, and examining each method's effects on reservoir operation. This study found that the Firm Supply Method could maintain water flow variability, but could not maximize water supply capacity. When the Deficit Supply Method was applied, water supply capacity could be increased while remaining vulnerable regarding water flow variability, as a difference between average flow and low flow was negligible at downstream. In comparison, the Selective Deficit Supply Method was found to sustain time-based reliability at 95% or higher, whereas downstream flow duration could be maintained at a level similar to the level generated by the Firm Supply Method.

• Journal of Korea Water Resources Association
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• v.42 no.12
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• pp.1091-1102
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• 2009

This study developed an integrated approach to climate change and urbanization impact assessment by linking models of SDSM (statistical downscaling model), HSPF (hydrological simulation program?Fortran) and ICM (impervious cover model). A case study of the Anyangcheon watershed illustrated how the proposed framework can be used to analyze the impacts of climate change and urbanization in terms of flood control, water security and water quality. The evaluation criteria were the variations of flow and pollutant concentration duration curves. In this study, nine scenarios including three climate (present condition, A1B and A2) and three urbanization scenarios were analyzed using HSPF model. As a result, climate change is a large influence on the flowrate and the urbanization affects the pollutant concentration. Therefore, the impacts of both climate change and urbanization must be included into the watershed management and water resources planning for sustainable development.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.271-283
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• 2006

A systematic water quality survey was conducted in August, 2005 for a drinking water supply reservoir (the Jeolgol reseuoir located in an island), which is at an early stage of impoundment, to investigate the causes of water color deterioration of the reservoir and the clogging of filter beds of a water treatment plant. The reservoir shape was simple and its average depth was 5.5 m, increasing from upreservoir toward the downreservoir end near the dam. Dissolved oxygen (DO) and chloropllyll-a (chi-a) showed a large variation while water temperature had a smaller range. Transparency ranged from 0.6 to 0.9 m (average 0.7 m). The average value of turbidity was 9.3 NTU, ranging from 8.0 ${\sim}$ 12.1 NTU. The transparency and the turbidity appear to be affected by a combination of biological and non-biological factors. The poor transparency was explained by an increase of inorganic colloids and algal bloom in the reservoir. The blockage of the filter bed was attributed to the oversupply of phytoplanktons from the reservoir. The range and the average concentration of chi-a within the reservoir were 31.6 ${\sim}$ 258.9 ${\mu}g\;L^{-1}$, 123.6 ${\mu}g\;L^{-1}$ for the upper layer, and 17.0 ${\sim}$ 37.4 ${\mu}g\;L^{-1}$, 26.5 ${\mu}g\;L^{-1}$ for the bottom layer, respectively. A predominant species contributing the algal bloom was Dinophyceae, Peridinium bipes f. occultatum. The distribution of Peridinium spp. was correlated with chi-a concentrations. The standing crop of phytoplankton was highest in the upreservoir with $8.5\;{\times}\;103\;cells\;mL^{-1}$ and it decreased toward the downresevoir. Synedra of Bacillariophyceae and Microcystis aeruginosa of Cyanophyceae appeared to contribute to the algal bloom, although they are not dominated. It is mostly likely that sloped farmlands located in the watershed of the reservoir caused water quality problems because they may contain a significant amount of the nutrients originated from fertilizers. In addition, the aerators installed in the reservoir and a shortage of the inflowing water may be related to the poor water quality. A long-term monitoring and an integrated management plan for the water quality of the watersheds and the reservoir may be required to improve the water quality of the reservoir.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.4
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• pp.15-28
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• 2017

A protected area means a space designated and protected by law from development pressure and environmental pressure. It is mainly designated to protect specific ecosystems, natural landscapes, and cultural resources from irrational development (or damage), and involves policies of the public sector such as central and local governments. The United Nations Educational, Scientific and Cultural Organization (UNESCO) has conducted conservation and restoration projects for preserving natural ecosystems and genetic resources. In order to conserve the ecosystem in the protected area, national and public organizations purchase private land and use it ecologically; in addition, ecological restoration project is carried out for the purpose of creating waterside ecological belt or preserving ecosystem. Land acquisition refers to the land where highly influenced by the water quality and need to restore, and purchased by negotiating with the landlord. Although the nation and public institution carried out ecosystem restoration project for partial purchase land in order to conserve ecosystem, it is below the expected effect due to lack of comprehensive management system and have some problems in restoration project and unification of management institutions. Land acquisition in Donggang River Basin Ecological Conservation area is initiated in 2005 for creating income of local residents and ecological restoration. However, the lack of overall management and awareness resulted in poor vegetation growth and poor response by local residents due to terrain exposure. As such, there is insufficient research on the current situation and systematic integrated management although the number of land acquisition is increasing year after year. Futhermore, overall recognition and follow-up monitoring of eco-restoration are still inadequate. Therefore, the survey on the awareness of the purchase land ecosystem restoration project is necessary for the efficient restoration project and establishment of the management strategy for land acquisition in the future. Therefore, in this study, we provide fundamental materials on further research projects by carrying out research on the awareness of ecological restoration projects in the Donggang River basin ecological preservation area.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.240-246
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• 2021

The Chironomidae is a benthic macroinvertebrate commonly found in freshwater ecosystems, along with Ephemeroptera and Trichoptera, which can be used for environmental health assessments. There are approximately 15,000 species of Chironomidae worldwide, but there are limited studies on species identification of domestic Chironomidae larvae. In the present study, we carried out species classification of the Chironomidae larvae that found in Jeju's tap water purification plants using morphological characteristics and genetic identification based on cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA. Body shape, mentum, antenna, mandible in the head capsule, and claws were observed in the larvae for morphological classification. Analysis of 17 larvae collected from faucets and fire hydrants of domestic tap water purification plants revealed the presence of two species, including 14 Orthocladius tamarutilus and 3 Paratrichocladius tammaater. These results will aid the use of the criteria information about species classification of the Chironomidae for water quality management in water purification plants and diversity monitoring of freshwater environments.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.235-241
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• 2022

According to the World Water Development Report 2015 released by the United Nations, drinking water is expected to decrease by 40% by 2030. This does not mean that the amount of water decreases, but rather that the water source is contaminated due to environmental pollution. Because microbes are deeply related to water quality, the analysis of microbe is very important for water quality management. While the most common method currently used for microbial analysis is microscopic examination of the shape and feature after cell culture, as the gene analysis technology advances, quantitative polymerase chain reaction (qPCR) can be applied to the microscopic microbiological analysis, and the application method has been studied. Among them, a reverse transcription (RT) step enables the analysis of RNA by RT-PCR. Integrated cell culture (ICC)-qPCR shortens the test time by using it with microbial culture analysis, and viability qPCR can reduce the false positive errors of samples collected from natural water source. Multiplex qPCR for improved throughput, and microfluidic qPCR for analysis with limited amount of sample has been developed In this paper, we introduce the case, principle and development direction of the qPCR method applied to the analysis of microorganisms.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.76-76
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• 2020

국가 물관리일원화 이후, 지방하천 관리에 대한 지자체 역할과 권한이 커지고 있으며, 중앙정부의 물관리 수준에 부합하는 데이터관리 체계구축 및 지속적인 품질관리(Quality Control, QC)와 표준화(Standardization) 기술개발이 요구되고 있다. 지자체의 경우 기존의 행정구역별로 분산 관리해오던 물관리 시스템을 유역단위로 전환할 필요가 있으며, 국가하천 구간과 연계한 종합적인 관리가 필요한 실정이다. 서울시의 물관리 시스템은 자치구별로 산재해 있으며, 관리 주체 및 해당 변수에 따라 제공되는 정보가 다르고 하천유역 단위로 분류되어 있지 않다. 따라서, 서울시와 자치구, 중앙정부 및 관련 기관과의 연계성 있는 정보제공을 위한 데이터 플랫폼 구축 기술개발이 필요한 실정이다. 본 연구에서는, 빅데이터, AI 기술을 활용한 물정보의 품질관리 자동화 기술개발과 지속적인 유지관리 및 표준화 정보제공 시스템 구축 기능을 포함하는 서울시 통합물관리 데이터 플랫폼 구축 목표 모델을 제시하였으며, 서울시 물관리 체계와 관련하여 SWAT 분석을 통한 단계별 사업추진 로드맵을 도출하였다. 분석결과, 서울시 통합물관리 플랫폼 구축을 위해서는 유역별 수량-수질 통합 모니터링 및 모델링 기술개발, 빅데이터 기반 물 정보화 플랫폼 구축 기술개발, 지방하천 유역 거버넌스 구축 및 법제도 정비 방안 마련이 요구되며, 관련하여 주요 이슈(3대 핵심전략, 10개 단위과제)를 도출하여 관련 연구과제를 제안하였다. 마지막으로, 서울시 통합물관리 정책 실현을 위해서는 법제도 마련이 시급하며, 서울시 '통합물관리 기본조례' 제정을 통한 기반을 조성할 필요가 있음을 시사하였다. 또한, 다양한 분야 이해관계자 협의체인 '서울시 통합물관리위원회(가칭)'의 거버넌스를 구성하여 운영하는 것이 현실적이며, 한강유역관리 및 지방하천 관리와 관련한 중추적인 역할 수행과 쟁점 논의 등 합리적 합의가 가능할 것으로 기대한다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.3-3
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• 2017

The question of how to establish sustainable agricultural systems has become as prominent as questions related to water, energy and climate change. High input/high output agriculture has brought with it many adverse effects; the massive deterioration of soil and water in both quantity and quality, increased greenhouse gas emissions and an increased prevalence of unsafe foods. Additionally, urbanization and climate change has worsened the shortage of farmland and reduced the supply of agricultural water. Given these challenges, maintaining, conserving and efficiently using agri-environmental resources, through fostering of sustainable agriculture, have emerged as key tasks in solving these problems. What is needed therefore is research, based on systematic and comprehensive empirical analyses, that can propose plans and methods for establishing an appropriate sustainable agricultural system. The empirical analysis of sustainable agricultural system is approached separately from economic, environmental and social aspects. An analysis of environment effect reveals that the available phosphate level is 1.3~2.1 times greater than the optimal amount in rice paddies, upland fields and orchards. Further examination has revealed that the excess nutrient is polluting both ground water and surface water. Analytical results for economic feasibility show that factors of production have been invested heavily in the rice crop. Under these conditions, sustainable agriculture, including low-input agriculture, appears to be a possible alternative that will facilitate simultaneous improvements in both economic feasibility and environment effects. Analysis results for sociality reveal that social factors include the value of producer, association and interior networks. Social conditions are comprised of leadership, consumers' awareness, education and conflict solutions. In addition, analysis as to the degree investments contribute to improving agricultural value added has revealed that the direct payment program is the most effective instrument. Experts confirm that economic feasibility can be improved by scientific and well-reasoned nutrient management on the basis of soil testing. Farmers pointed to 'economic factors' as being the largest obstacle to switching to the practice of sustainable agriculture. They also indicate 'uncertainty with regards to sustainable agriculture technology' as an impediment to practicing sustainable agriculture. Even so, farmers who believe environmental and regional issues to be the most pressing problems have expanded their practice of sustainable agriculture. The keys to establishing sustainable agriculture system are classified into the following four aspects. Firstly, from an economic aspect, the research indicates that agricultural policy needs to be integrated with environmental policy and that the function of market making based on the value chain needs to be revitalized. Secondly, from an environmental aspect, there is a need for an optimal resource management system to be established in the agricultural sector. In addition, sustainable agriculture practice will need to be extended with attendant environmentally-friendly and sustainable intensive technology also requiring further development. Thirdly, from a social aspect, green agriculture management needs to be fostered, technology and education extended, and social conflict mediated. Lastly, from a governance aspect, it will be necessary to strengthen good governance, assign and share suitable roles and responsibilities, build a cooperation system and utilize community supported agriculture.

• Journal of Korea Water Resources Association
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• v.50 no.10
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• pp.703-714
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• 2017

This paper analyzes the impact of two climate change scenarios on flow rate and water quality of the Yongdam Dam and its basin using CE-QUAL-W2 and SWAT, respectively. Under RCP 4.5 and RCP 8.5 scenarios by IPCC, simulations were performed for 2016~2095, and the results were rearranged into three separate periods; 2016~2035, 2036~2065 and 2066~2095. Also, the result of each year was divided as dry season (May~Oct) and wet season (Nov~Apr) to account for rainfall effect. For total simulation period, arithmetic average of flow rate and TSS (Total Suspended Solid) and TP (Total Phosphorus) were greater for RCP 4.5 than those of RCP 8.5, whereas TN (Total Nitrogen) showed contrary results. However, when averaged within three periods and rainfall conditions the tendencies were different from each other. As the scenarios went on, the number of rainfall days has decreased and the rainfall intensities have increased. These resulted in waste load discharge from the basin being decreased during the dry period and it being increased in the wet period. The results of SWAT model were used as boundary conditions of CE-QUAL-W2 model to predict water level and water quality changes in the Yongdam Dam. TSS and TP tend to increase during summer periods when rainfalls are higher, while TN shows the opposite pattern due to its weak absorption to particulate materials. Therefore, the climate change impact must be carefully analyzed when temporal and spatial conditions of study area are considered, and water quantity and water quality management alternatives must be case specific.