• Economic and Environmental Geology
• /
• v.33 no.4
• /
• pp.261-271
• /
• 2000

In order to evaluate the environmental impact of U anormaly in the drainage system around the Shinbo talc mine area, U contents, their distribution patterns, bioaccumulation and a-radioactivity in stream water, stream sediments and aquatic organisms were investigated. The U contents of stream water attenuated with increasing distance from the mine area. The same attenuation pattern is shown in stream sediments from mine to 0.75 km downstream, although these contain highly enriched U contents (24~83 mg/kg) comparing with the international average concentration of surface soils (0.79~11 mg/kg). However, U content increases abruptly in sediment at 1.5 km downstream, probably due to detrital migration and rediposition of U enriched sediments. Futhermore, enriched U in downstream sediments occur in high proportions of carbonate and Fe-Mn oxide bounded forms, which show high potential of a secondary pollution source. For aquatic organisms, bio accumulation degree of U are in the order: aquatic larvae>black snail>mountain frog>crawfish. Cultured trout by the U enrich groundwater (387 ${\mu}g$/l) shows U accumulation in the part of branchia (CRs 5.25) and bones (CRs 11.2) but not in flesh (CRs 0.03). Total a-radioactivity have been measured in the level as 0.47 nCi/l for groundwater, 2.94~18 nCi/kg${\cdot}$DW for organisms and 93~328 nCi/kg${\cdot}$DW for sediments.

• Journal of Environmental Impact Assessment
• /
• v.23 no.3
• /
• pp.187-196
• /
• 2014

The objective of this study is to evaluate and analyze Osu stream watershed water environment system. The data were collected from January 2009 to December 2011 including water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and discharge. The data were used for principle component analysis and factor analysis. The results are as followes. The primary factors obtained from both the principal component analysis and the factor analysis were BOD, COD, TOC, SS and T-P. Once principal component analysis and factor analysis have been performed with the collected data and then the results will be applied to both simple regression model and multiple regression model. The regression model was developed into case 1 using concentrations of water quality parameters and case 2 using delivery loads. The value of the coefficient of determination on case 1 fell between 0.629 and 0.866; this was lower than case 2 value which fell between 0.946 and 0.998. Therefore, case 2 model would be a reliable choice.The coefficient of determination between the estimated figure using data which was developed to the regression model in 2012 and the actual measurement value was over 0.6, overall. It can be safely deduced that the correlation value between the two findings was high. The same model can be applied to get TOC concentrations in future.

• Journal of Environmental Science International
• /
• v.9 no.6
• /
• pp.443-447
• /
• 2000

Chonan and Asan city have been a focal point due to rapid development as the first station for Express Railroad and key cities West Coast Development Region. Gokgyo stream adjacent to the cities plays an important role as a drainage channel for an agriculture and a discharger of urban storm water. Waster quality of the stream has been deteriorating caused by pollution sources such as a untreated wastewater discharge and runoff from the watershed. In the study, we conducted 4 surveys in April, May, July, and September to understand the current state of water quality for the stream and to make it possibe to predict future water-quality variation for future development. The system runs on a personal computer under the windows enviroment and provides extensive graphic user interface(GUI) for user-friendly assessment. Using the pull-down menus provided by the GUI panel, the user is able to operate the system by pointing and clicking the icon to identify the state of water-quality at locations concerned. Furthermore, we developed an integrated watershed management system. The constructed system could be a useful tool as a decesion maker for pollution source control strategy.

• Journal of Korean Society on Water Environment
• /
• v.25 no.1
• /
• pp.76-83
• /
• 2009

In 2005, the 5.84-Km length of Cheonggyecheon stream, previously covered with concrete road, was uncovered in the middle of Seoul, Korea. We investigated microbial water quality in various sites in Cheonggyecheon stream. We took water samples on three different days. The sampling sites included inflow water from upper stream (Mojeongyo), midstream (Ogansugyo), and downstream (Muhakgyo). Fecal pollution indicator microorganisms were measured by both IDEXX $Colilert^{(R)}$ and $Enterolert^{(R)}$. Microbial community from these sampling sites was also characterized based on 16S rRNA gene sequences. The average concentrations of total coliform are 5 CFU/100 mL, 1474 CFU/100 mL, and 1776 CFU/100 mL at Mojeongyo, Ogansugyo, and Muhakgyo, respectively. The average concentrations of fecal coliform were 28 CFU/100 mL, 47 CFU/100 mL in Ogansugyo, and Muhakgyo, respectively. The concentrations of other fecal indicator microorganisms including E. coli and Enterococcus sp. increased in downstream. When we characterized the microbial community, unique microbial community were discovered at different sampling sites. This study suggests that Cheonggyechoen stream is likely affected by non-point fecal sources and has unique microbial environment as the river flows downstream.

• Hwankyungkyoyuk
• /
• v.20 no.4
• /
• pp.12-26
• /
• 2007

The purpose of this research is to develop a water environmental education (EE) program using streams, based on the core ideas of ENVISION and materializing elements that were extracted in this research. This research realized the elements and presented a model of the water EE program using a local stream. First, this research developed a basic model of a water EE program using streams by extracting 10 materializing elements and realizing the elements in 4 stage-procedural model. The 10 materializing elements were 1. experiencing the process of inquiry, 2. inquiring local environments, 3. self-directing learning and mutual interaction with colleagues, 4. collecting real data and interpreting, 5. utilizing the ICT(information and communication technology), 6. inquiring with the view point of the 'Environmental Studies for EE', 7. inquiring with the watershed concept, 8. inquiring with the integrating and the holistic view point, 9. pursuing the macroscopic understanding about environment, and 10. connecting the real world phenomena with the environmental concepts and theories. This research materialized these 10 elements in 4 stage model, following the previous ENVISION research, which are 1. preparing stage and visual assessment, 2. writing the report of the inquiry plan, 3. collecting the real data in the environment and performing the investigation, and 4. presenting the inquiry results. Second, with using this basic model, this research developed and presented a model of the specific water EE program using a case stream called 'Baig Cheon' stream, which is a local stream. This research is considered to have a considerable meaning in developing a EE program with ENVISION ideas for the watershed concept and inquiry with environmental science using local streams. The developed model can help the professional development of teachers and teacher education of water EE.

• Journal of Wetlands Research
• /
• v.13 no.3
• /
• pp.643-655
• /
• 2011

This study addresses the periphytons along the Bukhan river stream and examines the biological indices that represents the river and estimate water quality assessment. Bukhan river in 4 major watershed streams (Bukchon-Hangeychon, Narinchon, Inbukchon, and Soyang river) was selected in 9 points. Land use pattern along the streams showed marked differenced in agriculture areas and forest areas. Lower Soyang streams showed blue-green algae and green algae also appeared in evenly pattern. Thus, the pollution source, biomass and distribution are somewhat correlated, and BOD, SS, biodiversity, and evenness showed a similar pattern. This situation can lead to conclusion of oligotrophic lake with good condition. Therefore, current biological index and is not so desirable for stream degree standard water quality and nutrient level.

• Journal of Korean Society on Water Environment
• /
• v.22 no.5
• /
• pp.796-804
• /
• 2006

The objective of this research was to develop ecological multi-metric models using natural fish assemblages for a diagnosis of current stream health condition, and apply the model to nationwide lotic ecosystems of the Geum River, the Youngsan River, and the Sumjin River. The ecological stream health model was based on the index of biological integrity (IBI), which was originally developed in North American streams by Karr (1981), and the Rapid Bioassessment Protocol (RBP), which was scientifically established by the US EPA (1999). The metric numbers and metric attributes were partially changed for the regional applications, so the scoring criteria was modified for the assessment. Overall, metric values, based on the IBI calculations, reflected conventional water quality characteristics, based on nutrient regime, and agreed with results of staticeco-toxicity tests. Some stations impaired in terms of stream health were identified by the IBI approach, and also major key stressors affecting the stream health were identified by additional evaluations of physical habitats. Our preliminary results suggested that biological integrity in stream ecosystems was largely disturbed by habitat degradation as well as chemical pollutions. This new approach would be used as a key tool for ecological restorations and species conservations in the degraded aquatic ecosystems in Korea and applied for elucidating major causes of ecological disturbances. Ultimately, this approach provides us an effective management strategy of stream ecosystems through establishments of ecological networks in various watersheds.

• Journal of Korean Society on Water Environment
• /
• v.28 no.3
• /
• pp.473-478
• /
• 2012

To protect human health and manage increasing hazardous chemicals in stream area, it is necessary to expand water quality hazardous items based on risk assessment with proper monitoring data. Also, it is essential to set up the suitable monitoring frequency to produce reliable exposure data to derive water quality guidelines. However, there has been no harmonized monitoring frequency for risk assessment in both domestic and international monitoring systems. In addition, the monitoring frequency for risk assessment has been selected as 'Research needs' in the International Conference on Deriving Environmental Quality Standards for the Protection of Aquatic Ecosystems (EQSPAE) of 2011. In this study, Cases of UNEP/WHO, EU, European countries, USEPA, ANZECC/ARMCANZ, CCME, Japan, and Korea were analyzed to propose the monitoring frequency for risk assessment. Monitoring frequencies depending on environmental conditions, monitoring object, measurement parameters, and monitoring duration were extensively collected. We observed that a monthly monitoring has been applied at most of organizations including EU, USEPA, and UNEP/WHO. In this study, monitoring frequency of minimum 6 times during 3 years were proposed to conduct the risk assessment based on the current domestic status. However, it is necessary to make agreements among interested parties, and perform additional studies about optimal monitoring frequency to protect the aquatic ecosystem and human health in Korean rivers and streams.

• Journal of Environmental Impact Assessment
• /
• v.20 no.1
• /
• pp.37-48
• /
• 2011

Recently, the social and environmental functions of nature river are important due to the increase of expectation for river restoration. So it should be considered the effect of vegetation affecting the conveyance capacity and hydraulic resistance. However, it has not yet proposed a objective standard and modeling method to estimate the effect of conveyance capacity according to vegetaion distribution in the watercourse such as water level or velocity. Therefore, this study simulates the variations of water level and velocity using 3-dimensional hydrodynamic model, EFDC, to consider a conveyance capacity in downstream of the Soyang Reservoir. The simulation results were validated using statistical index such as F-test and T-test. As results, the water level rises about 0.01 to 0.47m and velocity difference are about -0.95m/s to 0.23m/s.

• Journal of Korea Water Resources Association
• /
• v.40 no.7
• /
• pp.503-510
• /
• 2007

In the area of such a nature-friendly stream improvement, it is not established yet which engineering method is suitable for stream environment, due to lack of technology. Therefore, although nature-friendly stream improvement was done with expensive engineering method, the effect has not been fully confirmed, which results from the absence of overall valuation tool of stream improvement. In this regard, it is necessary to develop and apply comprehensive and diverse valuation methods covering stream functions to the analysis of stream improvement. In this study, we collected data from years' of monitoring on the Gyeongcheon river, which is located in Sunchang-eup, Jeollabuk-do and recently underwent an nature-friendly stream improvement work. Based on the data, we developed a series of valuation methods such as stream naturalness evaluation, life cycle evaluation, amenity evaluation, and economic benefit analysis to consider the environmental function of stream from a comprehensive perspective. Stream naturalness evaluation is a quantitative analysis of how natural a stream is, and includes additional valuation items such as ecosystem and water quality for the purpose of overall valuation, unlike existing research focusing on physical elements and structural characteristics of a stream. We developed a method of stream valuation with life cycle assessment to river reorganization project. Amenity evaluation method was developed as a means to analyze residents' satisfaction with stream improvement through questionnaires. Economic benefit analysis was developed as a means to determine the attributes of environmental water supply, ecosystem, river maintenance, and water quality and predict economic benefits using contingent valuation method (CVM) and multi-attribute utility analysis (MAUA) method in order to analyze economic benefits brought in by stream improvement. It is considered that the four methods developed in this study make possible to conduct an overall and quantitative analysis of stream improvement.