• Journal of the Korean Institute of Rural Architecture
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• v.17 no.2
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• pp.27-34
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• 2015

As part of the waterway restoration to renew traditional urban area, this paper is to assume and research Gyoseocheon(Gyoseo waterway) in Late 1960s Cheongju Korea. The main stream of Gyoseocheon flew from Sangjwagol(the head of the valley) of Uam Mt. to the north gate under Cheongju castle at first, and meandering from Sangdang Park, flew through Sudongseongdang and Bangadari Road to Musimcheon since open railroad of 1920s. This waterway, the eco-friendly figure of Gyoseocheon, that flew to inside the downtown with a planted tree and that is open space was so. The sub stream of Gyoseocheon originated in Seoundong and Tapdong were divided into two parts. One was to join the main stream of Gyoseocheon on Sangdang Park via Munhwadong, and the other was to join the sub stream of Musimcheon at northwest corner via south and west gate of Cheongju castle. This waterway as branch sewer were built into the road culvert.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.43-54
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• 2002

The Chonju and Samchun streams are palling though Chonju City and several contamination sources are located along these streams. The Samchun stream joins the Chonju stream in the Gosapyeong waste disposal site and the Chonju stream finally joint to the Mankyeong River. The Chonju and Samchun streams are now contaminated with BOD, COD, T-N and T-P and the amounts of each contamination are increasing from upper stream to downstream. At the downstream the amounts of COD. T-N.T-P are several times higher than fifth grade of water quality thor lacustrine. Sewage from Chonju provides BOD, COD,T-N and T-P into the Chonju and Samchun streams and Chonju Waste Water Treatment Plant il a main source of COD, T-N and T-P contamination. Gosapyeong waste disposal site may be the source of BOD and COD contamination. T-N is higher than fifth grade of water quality for lacustrine at the upper stream indicationg that the rivers are contaminated with T-N before inflowing into Chonju by agricultural activity. The Chonju stream asffects the contamination of the Mankyeong river with BOD. COD, T-N,T-P. Other branch steams of the Mankyeong river also affects the contamination of the Mankyeong river by BOD, COD, T-N and T-P, Among the branch streams, the Ikasn stream is a main contamination source. Amounts of concentrations inflowing from the Chonju and Sanchun Streams on Aug. 1999 are calculated by using yeasured flow rate find concentrations of contaminants The result are as fikkiws; 1) the amounts of influent from the Gosan Stream are 0.49, 0.86, 1.61 and 0.01 ton/day for BOD, COD, T-N and T-P, respectively, 2) compared to the amounts of influent from the Gosan Stream, BOD, COD,T-N,T-P supplied from the Chonju river are higher by about 5, 7, 7. 36 times, respectively, and those supplied from the Iksan stream are higher by about 13, 10, 10, 147 times, respectively.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.159-168
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• 1999

The ophemeropterans such as Epeorus pellucidus, Uracanthella rufa and Drunella uculea were dominated in station 1. It was generally showed the stable aquatic communities with low dominance index values throughout the year in station 2. The first dominant species in station 3 were all mayflies with the average DI value of 0.38. The first dominant species of Uracanthella rufa known as relatively tolerant species in station 4. A crustacean species Gammarus spp. have frequently occurred as the 1st or 2nd dominant species in station 5. Limnodrilus socialis, and Chironomus spp. were dominated in stations 6 and 7 Station 1, 2 and 3 were classified as oligosaprobic status according to their average diversity index values ranging from 3.46 to 3.52. Station 7 showed $\alpha$-mesosaprobic water condition with the overall average diversity value of 1.26. In general, the equitability and species richness values in the same sampling areas had close relations with their diversity values. The dendrogram drawn by dissimilarity values among 7 sampling sites indicates that the macrobenthic communities were divided into 3 groups： stations 1, 2, 3 and 4； stations 6 and 7； and station 5 alone.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.802-808
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• 2010

This study was carried out to apply the method of priority order selection for water quality improvement of watershed. The monitoring of flow and water quality, grouping branch streams and discharge load density were estimated on 18 branch streams located in middle and lower area of Geum River, Chungcheongnam-do. Based on average BOD concentration of stream at low flow, the results of the water quality analysis of stream which excess river living standard class 2 (less than BOD 3 mg/L) are Jeongancheon, Bangchukcheon, Gilsancheon, Jocheon, Seokseongcheon and Ganggyeongcheon. As a result of grouping stream, stream that have more than $10\;m^3/min$ of flow and more than 3.0 mg/L of average BOD concentration such as Group A are Jocheon, Seokseongcheon, Ganggyeongcheon and Jeongancheon. In Group A, stream corresponds to over than discharge load density as of 10 BOD kg/$day{\cdot}km^2$ is Jocheon, Seokseongcheon and Ganggyeongcheon. In view of the selected results to improve water quality basin through monitoring of flow and water quality, grouping stream, and estimation of discharge load density, Jocheon in Yeongi, Seokseongcheon located on the border of Buyeo and Nonsan, Ganggyeongcheon on Nonsan such as stream basin were urgent to improve water quality.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.36-43
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• 2020

BACKGROUND: Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities. METHODS AND RESULTS: Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, -2.11--0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites. CONCLUSION: The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• Journal of Korea Water Resources Association
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• v.43 no.1
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• pp.95-104
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• 2010

The tap water supply in Korea mainly depends on the surface water. However, the advanced water purification process becomes a necessity due to the deterioration of surface water quality and the risk of accidental spill. High cost of water treatment and public concerns make the decision makers turn to riverbank filtration as an alternative to the surface water. Riverbank filtration has been employed for water supply in many developed countries for more than 150 years. In Korea, riverbank filtration has drawn attention since 1990s as a supply source having potential to stably meet the ever-increasing water demand. Some cities located in the Nakdong River Basin are currently supplying water through riverbank filtration. This work studies the site suitability analysis for riverbank filtration using game theory. Theory of games, which is a branch of applied mathematics used in social sciences (most notably economics), biology, engineering and computer science, was applied to candidate locations for the selection of riverbank filtration site. We proposed a policy game model as a new method adopting a probabilistic approach. The model developed turned out to be an effective tool for site selection.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.95-102
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• 1990

Since the production of synthetic detergents in 1966, the demand of detergents increased rapidly during the past in Korea. Its production which was solely for donlestic consumption leaped from 402 tons in 1966 to 259387 tons in 1989. Practically all of these products were the anionic detergents primarily sodium salts of Alkyl Benzene Sulfonate(ABS). ABS persists for long periods in stream because of its resistance to triodegradation. Therefore synthetic detergents have been considered major contributors to water pollution. The detergents give a raise to be noted is foaming at sewage treatment plant and the drinking water contaminated by detergents have often been accompanying taste and odor. So the biodegradable Linear Alkyl benzene Sulfonate(LAS) has been adapted as the substituents for the Alkyl Benzene Sulfonate (ABS) since the 1980. However, the Inassive bubbles stemmed from use of synthetic detergents in the sewage treatment plant and the branch of tile Han River had been reported. Therefore, this investigation less undertaken so as to know the pollution of detergents in domestic sewage and the receiving river, and determine the biodegradation of synthetic detergents since ABS has been replaced by LAS in 1980. The study results on the pollution and biodegradation of synthetic detergents were as follows . 1. The major streams in Seoul were contaminated by synthetic detergents. The concentration of detergents were 2.48 mg/l of Anyangchon. 2. The biodegradation were determined by spontaneous settling and aeration. Since the LAS was substitute for ABS in 1980, detergents was more easy to biodegradable. The reduction ratio of Tanchon, Chungranchon, and Anyangchon were 15% , 11% and 16% by the settling and 76%, 77% and 82% by aerations for 5 days.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.149-158
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• 1990

The brook lamprey, Lampetra reissneri, was collected from an branch of the Nakdong River (Namwon-gun, Chollabuk-Do) and the Seomjin River (Hadong-Gun, Kyungsangnam-Do) from September, 1989 to April, 1990. Specimens were 95 individuals in number and composed of 21 ammocoetes, 16 metamorphosing animals and 58 adults which do not exceed 200mm in total length. The modal numbers of trunk myomer was 57.5, ranged from 55 to 60. In the dental formula, the supraoral tooth consistently had 2 cusps, and lateral circumorals were 3 in each side with 2 cusps. The infraoral had varying numbers of cusps ranging from 6 to 8. In morphological measurement of adults, prebranchial length was 10.3%, branchial length 9.7%, trunk length 51.3% and tail length 28.3% respectively, in hundreds of total length. No significant differences in morphological characteristics were observed between the two populations studied.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.400-410
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• 2015

Juniperus chinensis (Cupressaceae) is a valuable woody plant resource, but this rare plant is only distributed in restricted regions in Korea. In this study, we surveyed the geographic distribution regions, variation of sex ratio and the dynamics of natural populations of J. chinensis. in order to establish conservation strategies for the sustainable conservation of this important resource tree. The 17 natural populations of J. chinensis are restrictively distributed in the shore cliffs of (1) Ulleungdo island, (2) Gyeongju-si to Gangneung-si of the eastern coast, the riverside cliff along (3) Donggang-river of Jungsun-gun and Pyeongchang-gun and (4) branch of Nakdonggang-river in Uiseong-gun. The populations in Ulleungdo island showed continuous population distribution of over 200 individuals, but populations in other regions had discontinuous population distribution of under 200. The population of J. chinensis surveyed in Korea was estimated in ca. 3,200 individuals. The sex ratio (male/female) among populations of J. chinensis was diverse with variation from 0.46~1.67 range, but showed no significance. The sex ratio of the total individuals by species level was 0.74, and the percentage of female tree was significantly higher than the male. The results of dynamics analysis within population among regions showed that seedlings and saplings of J. chinensis in three regions surveyed were continuously regenerating. The distribution of DBH class showed a stable population structure of inverse J shape graph, but fragmentation and decrease in populations because of invading broad-leaved shrubs and trees from the surroundings were concerned. Further studies, and in situ and ex situ conservation strategies for the sustainable conservation on natural populations of this rare resources woody plant, J. chinensis in Korea are recommended.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.377-389
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• 2020

In this study, pollution characteristics were investigated for the Andong Dam sediments in the Nakdong River. Sediment samples were collected from the middle, left, and right points of the lake up to 40km upstream of the Andong Dam at intervals of about 5km by stratification and turnover period. In the case of nutrients and total organics such as loss of ignition, total nitrogen, and phosphorus, the degree of contamination is low, but heavy metals of arsenic and cadmium is very high. The contamination level of sediments in the dam area is higher than that of the branch of river and the control group, and concentration of chromium, copper, and lead are higher in the stratification period, and that of zinc is higher in turnover period. Arsenic, cadmium, manganese, and zinc showed contamination variation between upstream and downstream but chromium, copper, mercury, iron and lead didn't show the variation.