• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.15-23
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• 2010

Dry sieving, wet sieving and photoscattering analyzer were tested as particle size analyzing methods for sediments from rivers and lakes of Han river, Nakdong river, Youngsan river, and Kumgang river area. Dry sieving showed a big error due to coagulating effect over drying process and this phenomena was severe for lake sediment. Wet sieving and PSA showed an accurate results though wet sieving needs more labor and complicate processes. Freeze-dry or freeze-dry after oxidation of organics with hydrogen peroxide showed improved results but gave lower portion of fine particles in comparing with wet sieving. Heavy metal contents and extractable metal contents were investigated for the sediments and high heavy metal content and extractable amount were obtained from fine particles as expected. Using of proper particle size analyzing method is important and the sediment management should be focused on the fine particles.

• 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 ($0.6{\times}10/100ml$.).

• Journal of The Geomorphological Association of Korea
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• v.18 no.1
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• pp.1-13
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• 2011

The catch canal for a natural drainage, the excavation of tunnel for a stable irrigation, the artifical channelization of yazoo stream, many kinds of the pumping and drainage systems are found around Daedong-myeon, Gimhae-si. It could be confirmed that the deveolpment, maintenance and management of those facilities in the floodplain are mainly controlled by the geomorphological conditions. In case of Unha-chon, especially, the water can always be supplied only by openning the gate of irrigation tunnel and the Woldang pumping station as the largest pumping station in this area can supply water to Unha-chon area directly from the main river, Nakdong-gang. Because the Gamnae-chon which was an upper reach of the Unha-chon and is now connected to the Nakdong-gang through the Deoksan catch canal, the damage of flood and the burden of drainage are mitigated at the lower area of the Unha-chon.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.93-99
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• 2022

It was confirmed that the fish diversity decreased with increasing index of weir's density (IWD) in the four river systems. The IWD showed difference with watershed, it was high in the Nakdong River (NDR). Both two river systems of Gum River (GUR) and Yeongsan River (YSR) were similar, whereas relatively lower density observed in the Han River (HNR) system. A result of 2-Dimensional Kolmogorov-Smirnov (2-DKS) as a nonparametic test showed different threshold values affecting fish diversity with the river systems. The p-values based on D_max, were significantly different at 0.05 level (except for YSR). The threshold values affecting fish diversity were also different with watershed. The values were 1.6/km of the HNR, 1.3/km of the NDR, and 2.3/km of the GUR, respectively. The fish diversity was decreased when IWD is over threshold values. The IWD of total 404 rivers (about 33%) among 1,217 surveyed in this study showed above threshold value. These rivers should be considered first for evaluating river continuity. The IWD and threshold value suggested in this study would be useful for selecting a stream priority for river connectivity study.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.757-766
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• 2012

In this study, we have examined concentration distribution and patterns of PCBs in waters, sediments and soils in an agricultural area of South Korea to investigate the relationship between PCBs sources and concentration levels. The concentration of PCBs in water samples were ranged from lower values below detection limit to 8.25 ug/L and the concentration of PCBs in sediment samples were ranged from lower values below detection limit to 76.67 ug/Kg. The concentration of PCBs in soil samples were ranged from lower values below detection limit to 23.51 ug/Kg. These contamination levels were far below the guideline values suggested for environmental quality assessment. The homologue patterns in samples varied from sample to sample, but isomer patterns were very similar with each other. PCB-138 and PCB-153 were predominant congeners in the soil and sediment, which were similar to the results obtained from previous studies. With these results, the assessment of potential sources of PCBs contamination in the sediments of the Nakdong river basin was performed. The principal components were extracted by Principal Component Analysis(PCA). As the result of PCA, it could be expected that PCBs in samples of this study were more affected by PCB products than combustion processes and mostly affected by already-known sources. The PCBs in the soil and sediment samples were related with commercial PCB products.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.707-714
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• 2016

In order to prevent secondary pollution of tap water, corrosion characteristics are investigated, and corrosion index are calculated using LI and LR to manage corrosiveness. As targeted water treatment plants from 2014 (July, once) to 2015 (July and October, 2 times), 70 plants are selected by making a division for each area and water system. (treated water samples, n=240, raw water samples, n=72). In result of pH analysis, treated water was lower than raw water to 7.12, and 7.29, respectively. LI were investigated in the order of Seomjin river, Nakdong river, Han river, Geum river, to -2.08, -1.24, -1.11, -1.10 (at raw water), and -2.18, -1.59, -1.51, -1.35 (at treated water), respectively. In case of water quality goal value (LI = -1) in Japan as control of corrosiveness, management object was investigated about 83.3%.

• Journal of Navigation and Port Research
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• v.28 no.9
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• pp.821-825
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• 2004

The purpose of this study is the assessment of changes in the leisure patterns of users of the Eulsook-do before and after the estuary dike construction. The following survey research method was conducted to implement the study, sampling by age was carried out selectively and randomly alike. A total of 319 persons were chosen for final analysis, excluding questionnaires answered found to be inappropriate. To measure the image of the lower Nakdong River around the Eulsook-do, with advice sought from experts, researchers, through several pilot tests, developed a 24-item semantic differential scale(SDS) that has two bi-polar adjectives at each end Study of the pre- and post- construction images of the Eulsook-do located on the coast of Busan suggests the dike construction has brought about negative changes in the Eulsook-do's overall image. There can be two alternatives for improving the negative image: restoration and development.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.3-38
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• 2007

The depositional characteristics of Busan clay are initially described in this paper. The deposits of the Nakdong River estuary are composed of some different layers, which have been affected by marine transgression and regression. The upper clay layer is thick and soft. The lower clay layer and some depth of the upper clay layer have been leached by artesian pressure existing in an aquifer below. The clay shows unique physical and engineering characteristics due to leaching. Several large-scale reclamation projects have been performed in this delta area. The preloading method using long vertical drains has been applied for soft ground improvement. Experiences obtained from ground improvement are mentioned in connection with the depositional characteristics of the clay layers.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.28-34
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• 2010

This study was conducted to assess the validity of fecal coliforms to fecal streptococci ratio (FC/FS) for distinguishing the human from animal origin of fecal pollution in surface water. FC/FS ratio determined in effluent from municipal wastewater and human feces treatment plant (WWTP) and in downstream close to discharge of human feces was above 4 which indicates human origin. However FC/FS ratios determined seasonally in other water zones of the Nakdong River, even in the same sampling site, varied differently (above 4 or less than 0.7) due to different survival time of FC and FS and other environmental factors such as rainfall in watershed. Compared to other season, FC/FS ratios in winter were much lower regardless of the origin. It is concluded that the FC/FS ratio determined in surface water is not always valid for determining the origin of fecal pollution.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.138-144
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• 2006

Algal growth potential test (AGPT) has been used as a tool for assessing biological productivity potential in the aquatic ecosystems. This study was conducted to compare the productivity potentials of large reservoirs (Lakes Andong, Hapchon and Jinyang, and Naktong estuarine dam) and river sites (Sangju, Koryung, and Samlangjin) located in the Naktong River watershed. AGPT was conducted in both non-monsoon and mosoon season (February, April, July and September) of 2003, using Microcystis aeruginosa as a test alga. The AGPs in the reservoirs were relatively much lower than those of river sites. The river AGPs increased towards upstream close to the influent streams, while it generally decreased towards downstream. Immediately after the abrupt increase in influent discharge in summer, the AGP became similar between midstream and downstream sites. The water quality of river and reservoirs deteriorated during the drought period in accordance with AGP: it was the highest during this period. The AGPs showed the closest correlation with the P concentration, leading to the conclusion that bioavailable P is highly influential to the algal growth in both lentic and lotic ecosystems in the Naktong River watershed. Based on the AGPs, the water quality of tested sites was likely eutrophic. Our results suggest that AGPT be a useful tool in evaluating the productivity potential and trophic state of the water body as well as determining the nutrients that limit the growth of algae.