• Journal of Preventive Medicine and Public Health
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• v.23 no.1 s.29
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• pp.106-116
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• 1990

This study was conducted to investigate of water qualities in the upper and middle reaches of the Han River. For this purpose, water was sampled at Kwangjin and 1st Han-River Bridges of the Han River in Seoul and analysed from August, 1988 to September, 1989. The results are summarized as follows : 1. Water quality at 1st Han-River Bridge was more polluted than that at Kwangjin Bridge. 2. Except biological oxygen demand (BOD), turbidity, suspended solid (SS), dissolved oxygen (DO), DO saturation (DOS), ammonia nitrogen ($NH_3-N$), nitrite nitrogen ($NO_2-N$) and chloride ion ($Cl^-$) at Kwangjin and 1st Han-River Bridges were lower as compared with the previous data before redevelopment of the Han River. 3. SS, DO and pH at Kwangjin and 1st Han-River Bridges could be classified to the 1st grade in environmental water quality standard. DOS at Kwangjin Bridge was over 100% and that at 1st Han-River Bridge was below 100% in the Han River. BOD at Kwangjin Bridge could be classified to End grade and that at 1st Han-River Bridge to 3rd grade in environmental water quality standard. 4. The higher the level of water was, the lower the levels of turbidity and SS, and $NH_3-N$ was decreased with increasing water level at 1st Han-River Bridge. DO was decreased as water temperature went up but DOS was increased with DO. BOD was positively correlated with nitrite-nitrogens. 5. Turbidity and SS at the both sites and Chloride ion ($Cl^-$) at Kwangjin Bridge were increased in July and August. And DO at the both sites and $NH_3-N$ at 1st Han-River Bridge were decreased in at July and August.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.106-116
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• 2021

To secure basic data by monitoring the growth of salmon (Oncorhynchus keta) released to the Taehwa River. After discharge, the characteristics of the young salmon distribution and migration rate habitat were investigated for two years. A total of 4 points [Sunbawi bridge (St.1), Guyeong bridge (St.2), Samho bridge (St.3), and Myeongchon bridge (St.4)] were investigated. The survey of 2017 indicating an increase of 10 mm in average length and 0.8 g in average weight, and the survey of 2018 indicating an increase of 10 mm in average length and 0.5 g in average weight. Among 39 species, 10 insectivorous and 12 omnivorous, are believed to compete with young salmon for food. 6, 5, 6 and 8 predatory fish species has emerged at each site, respectively. According to this study, it is believed that St.1 and St.2 points are more proper as discharge location of young salmon because these two points have less varied in depth, flow rate, salt concentration etc. In addition, it is thought that the night or dawn time in early January is the best discharge time of young salmon fish because predatory fish such as Korean piscivorous chub and bass etc. does not eat food actively at that time.

• Water for future
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• v.29 no.1
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• pp.163-179
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• 1996

Flood flow characteristics of the Han River (from Goan to Indo Bridge) are analyzed using 1-dimensional St. Venant equations. NETWORK, a finite difference model, is used to calculate each term (local acceleration term, convective acceleration term, pressure force term, gravity force term, and friction force term) of the momentum equation and to analyze the flow characteristics. By the result of the study, as the general characteristics of flow in a channel that acceleration terms are very small and the other three terms are much greater is presented, three terms(pressure force term, gravity force term, friction force term) are to be main terms which decide the characteristics of flow. Specially in this region the acceleration term is noted so large that it cannot be ignored according to the shape of hydrograph and the region.

• Journal of Preventive Medicine and Public Health
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• v.4 no.1
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• pp.65-76
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• 1971

In view of ever rising water pollution problems of river in the vicinity of large urban communities, the author has made an investigation on the pollution of water sampled from Han River (Seoul area) and Nakdong River (Daegu city area) during the period from July to December, 1970. The water samples were taken twice a month during the study period of 6 months from 7 points (locations) along the main stream of Han River at Seoul city and 5 points of Nakdong River at Daegu city. The samples ware measured and analyzed in accordance with the recognized methods in the 'Standard Methods for Examination of Water and waste' by American Public Health Association. The obtained results are as follows : I. Han River. 1. Average turbidity was 5.1 units ranging from 1 to 10 units and the turbidity of down stream was higher than that of the upper stream. 2. pH value showed slight alkalinity (mean;7.2) except Yunchang-Dong (6.9). 3. The mean value of Dissolved Oxygen contents (D.O) was 7.2 ppm. (range of 3.4-10.5ppm.). D.O. of the upper stream (8.2 ppm. at Walker Hill boating place, 8.0 ppm. at the Gwangzang Bridge and Ddookdo) was higher than that of he downstream (5.6ppm. at Yumchang-Dong, 6.4 ppm. at the 2nd Han River Bridge), and D.O. in the winter season was higher than that in the summer season, respectively. 4 The mean value of the Biochemical Oxygen Demand (B.O.D.) was 28.3 ppm. (range of 6.2-64.8 ppm.). The mean value of B.O.D. was 48.7 ppm. at Yumchang-Dong, 42.3 ppm. at the 2nd Han River Bridge, 34.0 ppm. at the 1st nan River Bridge, 28.5 ppm. at the 3rd Han River Bridge, 19.2 ppm. at Dookdo, 13.2 ppm. at the Gwangzang Bridge, and 10.2 ppm. at the Walker Hill boating place in order of value. B.O.D. in July and August (35.6 and 34.5 ppm.) were the highest and that in November and December (18.6 and 21.2 ppm.) were the lowest. 5. Suspended Solids (SS) were from 15.0 to 667.0 ppm. with the mean of 222.1 ppm. 'Suspended Solids' of the water samples at Yumchang-Dong and the 2nd Han River Bridge were found to be 378.1 ppm. and 283.9 ppm. respectively which were higher than at the Gwangzang Bridge (134.1 ppm.) and at Walker Hill boating place (79.3ppm.). 6. Coliform colonies counting of the water samples ranged from $0-2,500{\times}10/100ml$. with the mean value of $205.6{\times}10/100ml$. The most contaminated water sample by coliform were from the point of the 2nd Han River Bridge with $640.8{\times}10/100ml$ while the lowest ones were from Walker Hill boating place with $17.2{\times}10/100ml$. There was also a seasonal variation in coliform contamination that is the higher in summer and the lower in winter. II. Nakdong River 1. The mean value of turbidity was 2.3 units with range of 0 to 9.0 units. The highest point was at Geumho River (7.2 units). and the lowest point was at Gangzung and Moonsan (0.45 and 0.41 units). 2. The mean value of pH was 7.5 (range of 7.1-8.5) and highest point was Geumho River with 8.5. 3. The mean value of D.O. was 8.1 ppm. (range of 3.4-11.2 ppm.). D.O. of the upper stream showed higher value than that of the down stream, and the winter season than the summer season. 4. B.O.D. ranged from 2.6 to 57.0 ppm. (mean; 20.4ppm.). The water sample at Geumho River showed the highest value (41.5 ppm.) while at Moonsan and Gangzung showed the lowest (4.6 and 4.7 ppm.). 5. The mean value of suspended solids was 48.7 ppm. (range of 4.0-182.0 ppm.). The highest month was July (63.7ppm.) and August (62.1 ppm.) and the lowest month was October (37.0 ppm.) and December (24.4 ppm.). 6. The mean value of the coliform colonies was $22.7{\times}10/100ml$. (range of $0-243{\times}10/100ml$.). The highest number of the colonies was found in the sample water at the Whawon recreation area ($50.5{\times}10/100ml$.) followed by the Geumho River ($33.9{\times}10/100ml$.), the Goryung Bridge ($28.3{\times}10/100ml$.), Gangzung($0.7{\times}10/100ml$), and Moonsan ($0.6{\times}10/100ml$.).

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.395-402
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• 2007

Concentrative samplings of 35 times on standing crops of phytoplankton and physicochemical factors were conducted at five sites over Seongsu Bridge to Seongsan Bridge in lower parts of the Ban River from January to December 2006. Over the study, all physicochemical factors showed no large differences among the sampling sites except station 2 having high concentrations of BOD, TN, and TP. Heavy rain also cause these concentrations to decrease. The phytoplankton species and abundance (88 taxa and $1{\sim}41$,104 cells $mL^{-1}$) were varied according to the season, and sharply decreased during heavy rains. In particular, cyanobacteria dominated the phytoplankton community during dry seasons, while green algae and diatom dominated during the rainy seasons. However, after the termination of rain, high water temperatures over $20^{\circ}C$ and low N/P ratios $(9.4{\sim}18.9)$ evoked the cyanobacterial bloom. These results indicate that although the heavy rain (huge outflows of Paltang Dam) temporarily diluted the nutrient level and effected the cyanobacterial bloom in the lower parts of the Han River, cyanobacterial abundance was recovered by the high temperature and low N/P ratio as the rainfall discontinued.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.61-67
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• 2008

This study analyzes the characteristics of material transportation between Busan new-port and Nakdong river estuary. Measurements of water temperate, salinity, turbidity, and tide is also analyzed to determine the characteristics of sea water and described the tidal current between two regions. For the purpose of indicating characteristics of tidal current numerical modeling is used. From the observed results, the total volume transport of sea water calculations revealed $184.71m^3/sec$ and residual volume transport was $(+)59.74m^3/sec$ during the 1st field measurement, and the total volume transport was $331.15m^3/sec$ and residual volume transport was $(-)28.88m^3/sec$ during the 2nd. The numerical simulation for three different topography cases are calculated. The results are summarized as follows: 1) The volume of material transportation about $0.7\sim18.4%$ is decreased as the depth of Busan new-port decrease (10 m). 2) The volume of material transportation about $3.5\sim21.9%$ is increased, as channel(water depth is 5 m) constructed to the Nakdong river estuary direction.