• Journal of the Korean association of regional geographers
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• v.10 no.3
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• pp.568-578
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• 2004

This study is aimed at investigating floodgate characteristics and environmental issues in Gwangjucheon and examining possible problems of expanding river maintenance water being carried on in the context of river recovery works. In general, the obtained results show the following. The treatment water provisioned in the restoration project of the drying stream going through the water circulation device can pollute the land and groundwater in the Gwangjucheon Basin. Besides, although about $17,565m^3$/day of water is available in the upper ground, most of it go to the junction and exhausting directly to the waste water treatment or going into the groundwater. Because of the drying stream, the amount of water going to the ground is increased. Therefore, efficient land use along with regulations to protect cultivated land and ensure recovery works of city stream through the recovery of water circulation by constructing and expanding a special drainage system are of vital importance.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.531-538
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• 2024

While the importance of the water quality environment is being emphasized, the water quality index for improving the water quality of urban rivers in Gwangju Metropolitan City is an important factor affecting the aquatic ecosystem and requires accurate prediction. In this paper, the XGBoost and LightGBM machine learning algorithms were used to compare the performance of the water quality inspection items of the downstream Pyeongchon Bridge and upstream BanghakBr_Gwangjucheon1 water systems, which are important points of Gwangju Stream, as a result of statistical verification, three water quality indicators, Nitrogen(TN), Nitrate(NO3), and Ammonia amount(NH3) were predicted, and the performance of the predictive model was evaluated by using RMSE, a regression model evaluation index. As a result of comparing the performance after cross-validation by implementing individual models for each water system, the XGBoost model showed excellent predictive ability.

• Journal of the Korean earth science society
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• v.24 no.4
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• pp.346-360
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• 2003

In order to investigate the geochemical characteristics of surface sediments in streams of Gwangju City, sediment samples from the main stream of Yeongsan river, Hwangryong river, and Gwangjucheon in the city were collected and analyzed for grain size and metal and organic carbon contents. The sediment types of the streams widely vary from pebble to mud. The metal contents in the sediments from Yeongsan river and Hwangryong river are mainly dependent on the grain size of the sediments and the geology around the streams, while the sediments in Gwangiucheon are controlled by organic matter contents from the domestic sewage. The enrichment factor (Ef) and index of geoaccumulation (Igeo) representing the degree of metal contamination in the sediments are relatively low in the mainstream of Yeongsan river and Hwangryong river. However, those of Gwangjucheon show EF values of P=8.30, Cu=5.54, Zn=14.28 and Pb=7.41 and Igeo values of P=3.78, Cu=2.79, Zn=3.66 and Pb=1.59. The heavy metal contamination is especially significant near the area where the Seobangcheon and Donggyecheon branches of Gwanjucheon, join. Therefore, it is suggested that the metallic contaminations of these small streams are significantly influenced by the domestic sewage of the city.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.504-513
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• 2013

Water quality trends for major tributaries (66 sites) in the Yeongsan River basin of Korea were examined for 12 parameters based on water quality data collected every month over a period of 12 months. The complex data matrix was treated with multivariate analysis such as PCA, FA and CA. PCA/FA identified four factors, which are responsible for the structure explaining 78.2% of the total variance. The first factor accounting 27.3% of the total variance was correlated with BOD, TN, TP, and TOC, and weighting values were allowed to these parameters for grade classification. CA rendered a dendrogram, where monitoring sites were grouped into 5 clusters. Cluster 2 corresponds to high pollution from domestic wastewater, wastewater treatment and run-off from livestock farms. For grade classification of tributaries, scores to 10 indexes were calculated considering the weighting values to 3 parameters as BOD, TN and TP which were categorized as the first factor after FA. The highest-polluted group included 10 tributaries such as Gwangjucheon, Jangsucheon, Daejeoncheon, Gamjungcheon, Yeongsancheon. The results indicate that grade classification method suggested in this study is useful in reliable classification of tributaries in the study area.

• Korean Journal of Plant Taxonomy
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• v.39 no.4
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• pp.309-314
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• 2009

Two naturalized species, Glyceria declinata $Br{\acute{e}}b$. and Puccinellia distans (Jacq.) Parl. are herein newly reported from Korea. Glyceria declinata, 'Yu-Reop-Yuk-Jeol-Bo-Ri-Pul', was found along the Seomjin River, Gurye-eup, Gurye-gun, Jeollanam-do, as well as along the Gwangjucheon River, Sa-dong, Dong-gu, Gwangju. It is distinguished from G. acutiflora by spikelets 15-20mm long and obtuse lemma. Puccinellia distans, "Cheo-Jin-Mi-Kku-Ri-Gwang-I", was found in Yeongjong Island, Incheon, Yongyu Island, Incheon and Chojijin, Ganghwa-gun. It is distinguished from P. nipponica by lemmas 1.8-2.5mm long, ligule 1-2mm long and the lower branches of panicle usually reflexed after anthesis.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.42-51
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• 2012

This study investigated the characteristics of natural organic matter (NOM) with general water characteristics (pH, DO, electrical conductivity, BOD, COD, TN, TP, Chl-$a$, DOC, $UV_{254}$, SUVA) and the 3D fluorescence excitation-emission matrix (FEEM) in the Yeongsan River basin. FEEM was used to classify protein-like and fulvic & humiclike substances with fluorescence intensity in the matrix of excitation and emission wavelength. The concentration of BOD, COD, TN, electrical conductivity and DOC in the region of Gwangju city (Gwangju sewage treatment plant: GJS, Gwangjucheon: GJC, Gwangju 2: GJ2) was relatively higher than the upper reaches and lower reaches of the Yeongsan River basin. SUVA in most sites was lower than 3 L $mg^{-1}\;m^{-1}$ as the hydrophilic substances, except Damyang (DY) in the upper reaches of Yeongsan river was higher than 3 L $mg^{-1}\;m^{-1}$ as the hydrophobic substances during winter and autumn. In the FEEM investigation the fulvic and humic substances were found in most sites, and in sites regarding Gwangju city (GJS, GJC, GJ2) during winter and GJC in summer, protein-like substances were found. The trend of fluorescence intensities from the upper reaches to the lower reaches in most sites corresponded to that regarding the concentration of water characteristics (BOD, COD, TN, DOC). That is why the region of Gwangju city (GJS, GJC, GJ2) was relatively higher. This results were an equivalent trend to those of fluorescence index (FI) in most sites, and the higher FIs in the sites of Gwangju city indicate more microbial-derived substances due to enormous effluent organic matters (EfOM) from huge Gwangju sewage treatment plants.