• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.102-105
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• 2003

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.699-712
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• 2000

Juam lake is a major water resource for the industrial and agricultural activities as well as the resident life of Kwangju and Chonnam regions. However, the water quality of the lake is getting worse due to a large quantity of pollutant inflowing to the lake. Thus, the strategy for achieving the water quality goal of the lake should be developed as soon as possible. When there are various alternatives that can be used as the strategy, several criteria based on the achievement degree of water quality goal, the applicability of technique and social environment, and the reasonableness of the cost required are made to evaluate and rank the alternatives. However, it is difficult to make a decision when there are multiple criteria and conflicting objectives and specifically the estimated values of criteria contain elements of uncertainty. The uncertainty stems from the lack of available information, the randomness of future situation, and the incomplete knowledge of expert. As the degree of uncertainty is higher, the decision becomes more difficult. In this study, a fuzzy decision-making method is presented to assist decision makers in evaluating various alternatives under uncertainty. The method allows decision makers to characterize the associated uncertainty by applying fuzzy theory and incorporate the uncertainty directly into the decision making process for selecting the "best" alternative so decisions can be made that are more appropriate and realistic than those made without taking uncertainty in account.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.877-886
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• 2022

This study was carried out to analyze how the flow and water quality of the Sangsa Lake (juam control basin) change according to future climate change and what countermeasures are needed. Aquatic Ecosystem Model) was used in conjunction. As climate change scenarios, RCP (Representative Concentration Pathways) 4.5 and RCP 8.5 scenarios of AR5 (5th Assessment Report) according to the Intergovernmental Panel on Climate Change (IPCC) were used. For the climate change scenario, detailed data on the Sangsa Lake basin were used by the Korea Meteorological Administration, and after being evaluated as a correction and verification process for the 10-year period from 2012 to 2021, the present, 2025-2036, 2045- The summer period from June to August and the winter period from December to February were analyzed separately for each year by dividing it into 2056 and 2075-2086. RCP 8.5 was higher than RCP 4.5 as an arithmetic mean for the flow rate of the watershed of the superior lake for the entire simulation period, and TN and TP also showed a tendency to be higher at RCP 4.5. However, in RCP 8.5, the outflow of pollutants decreased during the dry season and the outflow of pollutants increased during the summer, indicating that the annual pollutant outflow was concentrated during the flood season, and it is analyzed that countermeasures are needed.

• Journal of environmental and Sanitary engineering
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• v.19 no.2
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• pp.51-59
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• 2004

강우가 집중하고 남조류가 대발생하던 시기의 중영양호소인 주암호에서 박테리아, 식물플랑크톤, ANF, HNF, 섬모충플랑크톤, 동물플랑크톤과 환경요인들의 변화에 대해 조사하였다. 조사기간동안 우점종은 Cyclotella meneghinana, Aulacoseira granulata, Cryptomonas tetrapyrenoidsa로서 총현존량의 67% 이상을 차지하였다. 조사기간동안 남조류 대발생의 구성원은 현존량 및 종조성에서 크게 변화 하였다. 여름철 강우에 의한 엽록소 a, 수질 (COD, TP)의 변동이 심하였으며, 특히 C. tetrapyrenoidsa는 HNF, nauplii, rotifer, 섬모충의 변동에 매우 밀접한 관계를 보였다. 포식자인 rotifer는 박테리아, 피코플랑크톤이나 ANF같은 소형플랑크톤의 변동과 높은 관계를 보였다.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.1027-1033
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• 2009

For the assesment of pollutant loads, a monitoring has been conducted to identify hydrologic conditions and water quality of the Oenam watershed in Juam Lake, and the SWAT model integrated with GIS was applied to the watershed and evaluated for its applicability through calibration and verification using observed data. For the model application, digital maps were constructed for watershed boundary, land-use, soil series, digital elevation, and topographic input data of the Oenam watershed using Arcview. The observed runoff was 832.8 mm while the simulated runoff was 842.8 mm in 2003. The model results showed that the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability of the model. In terms of nutrient load, the simulation results of T-N, T-P showed a similar trend to observed values. The observed T-N load was 10.8 kg/ha and the simulated T-N load was 7.6 kg/ha while the observed T-P load was 0.21 kg/ha and the simulated T-P load was 0.18 kg/ha. In general, SWAT model predicted observed runoff and loads of T-N and T-P after calibration with observed data in acceptable range. Overall, SWAT model was satisfactory in estimation of nutrient pollutant loads of the rural watershed.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1235-1244
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• 2012

The objective of this study is to evaluate Flow-Pollutant load delivery ratio equations developed from rural watershed on main subwatersheds within Juam Lake. Two regression equations for BOD and three equations for T-P were evaluated on Bosung cheon, Dongbok cheon, Songgwang cheon, Naenam cheon, and Sinpyeon cheon. The results show that estimation of BOD delivery ratio using flow-delivery equation is reliable when relative composition of discharge load of pollutant sources of a watershed is similar to those of watershed where the equation developed. On the other hand, application of regression equation for T-P was feasible when the landuse pattern and relative composition of discharge load of pollutant sources of a watershed is similar to those of watershed where the equation developed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.173-184
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• 2014

Riparian areas are significant functional grounds for inhabiting ecological system on the river such as the self-regulation of the water quality and the foundation of important corridors. For such functional device to operate, consecutive land purchase scheme that prioritizes targeted areas with high pollutant load rate imposes sustainable development of the ecological riparian belt. The purpose of this study is focused on measuring the methodology for selecting land purchse order before establishing riparian belt in accordance with pollution loading estimation and the basin approach. The Yeongsan and Seomjin river which includes targeted areas of the land purchase have been classified into the large-medium-small(standard basin) influence areas based on their catchment rage, which than sub-divided the research area of Juam lake by 38 small basins and 223 units. Small basins with the high pollution load rates have been assessed as the first prioritized targets. For the second priority, the condition of the point pollutant sources, original area of the targets, original restored area were concerned. The final decision of the land purchase order targeted only those within 50 meter range from the basin. To validate the accumulated data, the on-site investigation went along the targeted zones, which the result shows that all prioritized areas included both point and non-point pollutant sources, and had not a small originally restored areas.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.144-152
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• 2011

BACKGROUND: Eutrophication occurs occasionally in flood control reservoirs around Juam lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during water surface is rising after rainy season. METHODS AND RESULTS: To improve water the quality of water from water supply source and to establish the management plan of submerged plants in flood control reservoirs around Juam Lake, the removal and release velocities of nutrients by submerged plants in site 1 and 2 were investigated. Removal or release velocity constant (K) of COD by Carex dimorpholepis Steud in column was 0.07~0.18 $day^{-1}$ at 0~4 days after flooding, -0.23~-0.17 $day^{-1}$ at 5~19 days after flooding and -0.28~0.03 $day^{-1}$ at 20~33 days after flooding. Removal or release velocity constant (K) of T-N by Carex dimorpholepis Steud was 0.02 $day^{-1}$ at 0~4(8) days after flooding, -0.13~-0.10 $day^{-1}$ at 5(9)~33 days after flooding in column. Removal or release velocity constant (K) of T-P by Carex dimorpholepis Steud was 0.05~0.06 $day^{-1}$ at 0~4 days after flooding, -0.14~-0.09 $day^{-1}$ at 5~33 days after flooding. Release velocity constant (K) of nutrients by Miscanthus sacchariflorus Benth was lower than that by Carex dimorpholepis Steud. In site 1, the amount of nutrients release by Carex dimorpholepis Steud was 6,719 kg/month/area for COD, 2,397 kg/month/area for T-N and 466 kg/month/area for T-P. The amounts of nutrients release by Carex dimorpholepis Steud were higher than those by Miscanthus sacchariflorus Benth in both sites. CONCLUSION(s): The results of this study suggest that COD, T-N and T-P in water quality of Juam lake were strongly influenced by submerged plants in flood control reservoirs.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.30-40
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• 2009

Employing the Numata-type life form, the paper analyzed changes of plants for 4 years at the Human-made Wetlands along Boknaecheon of Juam Lake since its creation. The number of the species planted at the Human-made Wetlands along Boknaecheon of Juam Lake, which was completed in December 2002, were 15 in total including, 10 families, 13 genera, 12 species and 3 varieties. As for the three-featured life forms of the planted species, there were 6 perennial hydatophytes, recording the biggest number of species in dormancy form; species each of $R_5$, $R_3$, $R_{2-3}$ respectively in radicoid from; 20 species of geomantic dissenminule form ($D_1$) in disseminule form and erecred type(e) existed the most in growth form. With regard to the 3 features of life form identified during the final year of the monitoring that lasted 5 years after the completion of the Wetlands, the number of species and individuals was found to have increased but there was no significant change of tendency as against the composition ration(%) of life form. There were 43 species of therophytes (Th) that covered 24.29% in dormancy form, while $R_5$ was prevalent in radicoid form and $D_4$, $D_1$, and $D_{1,4}$ comprosed 77.39% of the whole disseminule form. Growth form was surveyed in the order of erected type (e), bunch type (t), temporal rosette type (pr), branch type (b) and straight rosette type (ps) and these species comprised 64.97% of the whole flora. Consequently, in case of the artificial wetlands along the Boknaecheon of Juam Lake, it turned out that the vegetation type in which pioneer species of succession, or gradually stabilized perennial vegetation favoring Wetlands because the higher dormancy form has its perennial plants' composition ratio getting, the more its succession is progressing. Even though single grained plants ($R_5$) belonging to radicoid in breeding form, succession is predicted to take place considering the fact that they actually belong to ~ plants like Phragmites japonica that form a connection on the surface of the earth. In addition, it is judged that geomantic disseminule form ($D_1$) conveyed by water and gravitational disseminule form favored by the development of waterside woody plants ($D_4$) seem to be better fit to this area in desseminule form. As for growth form, bunch type (t) is judged to become prevalent on the Wetlands while a good variety of phanerophytes will coexist on the earth due to artificial as well as natural disturbances.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.922-928
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• 2011

In order to properly manage the quality of water in Juam Lake, distributions and growth characteristics of submerged plants in Boknae flood control reservoir were investigated. In addition, the total amount of nutrient load by submerged plants were investigated. The total vegetation area was $1,146,849m^2$ of total flood control reservoirs ($1,848,568m^2$) before flooding. By August 19, all of Boknae flood control reservoir was flooded during rainy season. Dominant plants were MISSA (Miscanthus sacchariflorus), SCPMA (Scirpus fluviatilis) and CRXDM (Carex dimorpholepis) which occupied 87% of all flood control reservoirs. The total amounts of organic matter loads at different submerged plants were great in the order of CRXDM ($501,642kg\;area^{-1}$) > SCPMA ($20,987kg\;area^{-1}$) > MISSA ($3,413kg\;area^{-1}$). The total amounts of nitrogen loads by CRXDM, SCPMA and MISSA under different submerged plants were 56%, 3.9% and 0.8%, respectively. The total amounts of phosphorus loads at different submerged plants were on the order of CRXDM ($1,842kg\;area^{-1}$) > SCPMA ($78kg\;area^{-1}$) > MISSA ($14.8kg\;area^{-1}$). Therefore, the results of this study suggest that organic matter, T-N and T-P in water quality of Juam lake were strongly influenced by submerged plants in flood control reservoir.