• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.137-149
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• 2020

This study was carried out to analyze the monthly runoff concentration on non rainfall days in order to prepare basic data to compare the runoff concentration on rainfall days in 7 forest watersheds in the Republic of Korea. Forest stream water has been collected through 15 times of sampling in each watershed and analyzed based on the changes in concentration of Biochemical Oxygen Demand(BOD), Chemical Oxygen Demand(COD), Total Organic Carbon(TOC), Total Nitrogen(TN), and Total Phosphorus(TP). The average concentration was 0.8 mg/L for BOD, 1.4 mg/L for COD, 0.8 mg/L for TOC, 1.85 mg/L for TN and 0.002 mg/L for TP during non rainfall days. Coniferous forested watersheds showed higher value of TN and TP concentration. Concentrations of BOD and TP in early March (p<0.01) were affected by melt water flow input in spring season. Significant differences (p<0.01) in concentrations were observed in BOD and TOC, indicating seasonal rainfall and vegetation growth impacts on forest stream quality. Concentration of TN and TP showed significant positive correlation, and weak negative correlation was found in the concentration of BOD and TOC. It is expected that result of forest stream water on non rainfall days could be basic information in managing non-point source from forest watersheds.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.4
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• pp.228-232
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• 1970

From the standpoint of fishery science it is an interesting matter to note that the size of Plecoglessus altivelis population on Cheju Island is smaller than that of the Nakdong River located in the southern part of Korea's mainland. Therefore the author carried out a comparative analysis to determine whether the populations differ because of racial or because of environmental conditions. The morphometric characters of the head length and the body length were used for the analysis of covariance and computed by a standard regression method of testing for the homogeneity of the populations. All samples were collected during 1968 and 1969 in the Milyang Stream of the Nakdong River and the Cheonji Stream of Cheju Island. The results of the analysis of the populations based on the significance test are as follows: 1. Since the F value observed was only 1.023 ($n_1=1,\;n_2=42$) the conclusion was reached that the samples could both belong to the same population. 2. In comparison with the deviations of the regression coefficients between the fish of the Nakdong River and Cherinji Stream, the populations were also highly significant suggesting that thelr belong to the same population. 3. The conclusion is that the fish of Cheju Island became a smaller fish in size due to an environmental condition but not due to racial characteristics.

• Water for future
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• v.20 no.4
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• pp.267-278
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• 1987

This study aims at the decision of geomorphologic instantaneous unit hydrograph(GIUH) model parameter fore the ungaged or the data deficiented Basin, to analyze rainfall runoff relation in river basin by applying queueing theory with geomorphologic factors.The concept of GIUH model is based upon the principle of queueing theory of rain drops which may follow many possible routes during rainfall period within watershed system to ist outlet. Overland flow and stream flow can be simulated, respectively, by linear reservoir and linear channel conceptual models. Basically, the model is a mon-lineal and time variant hydrologic system model. The techniques of applying are adopted subarea method and mean-value method, the watershed is divided according to its stream number and order. To prove it to be applicable, the GIUH model is applied to the Wi-Stream basin of Nak-Dong River(Basin area; 475.53$\textrm{km}^2$), southen part of Korea. The simulated and the observed direct runoff hydrographs are compared with the peak discharge, times to peak and coefficients of efficiency, respectively, and the results show quite satisfactory.Therefore, th GIUH model can be extensively applied for the runoff analysis in the ungaged and the data deficiented basin.

• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.127-134
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• 2014

Organic carbon and nitrogen stable isotope ratios of particulate organic matter (POM) were determined at 7 stations (6 stations in Han river and Paldang dam outflow station) from May to October 2013, in order to understand the origin of POM at the Han river. ${\delta}^{13}C$ values of POM in four stations showed significant seasonal changes season, but ${\delta}^{15}N$ values were enriched in around Kyeongan stream (K). POC, PN and Chl-a concentration showed a similar seasonal pattern in Kyeongan stream, with an apparent decrease from July to August. POC and PN concentration has a higher correlation with Chl-a concentration in Kyeongan stream (K). ${\delta}^{13}C$ and ${\delta}^{15}N$ values of POM has a lighter value during lower Chl-a concentration peroid, compared to other seasons. Our results revealed that Kyeongan stream (K) seemed to be influenced by substantial amount of organic manure or fertilizer input in 2013, compared to the previous year (2012). These results suggest that the analysis of stable isotope ratios is a simple but useful tool for the identification of organic matter origin in aquatic environments.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.3
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• pp.60-70
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• 1999

The purpose of this study is to analyze the spatial change of water quality pollutant in the upper-stream of Kumho River basin. For this purpose, it compared with ground survey data of water quality measurement, using GIS and Landsat TM image, and then constructed a database of water quality pollutants in the watershed by Arc/Info. Also the land cover classification maps of 1985 and 1997 were prepared using maximum likelihood classification. This study detected and analysed the classified images to produce the area of land cover change per sub-basin. In addition, choropleth maps were prepared with spatial change value of water quality pollutants, and overlay analysis was carried out with weight score for each layer. The results of this study revealed that population, animals and fruit orchards were main factors in the spatial change of water pollution of Kumho River basin. The Comparision of pollutions by sub-basins showed a high pollution value in Daechang-chun and Omok -chun stream which follows through the urban area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.98-109
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• 2001

This study aimed to investigate the effect of revegetation technique for water attacking point using waterlogged prevention frame revetment. In this study, we evaluate frame revetment stability, water quality, plant growth and ecological and envirnomental changes in Mooshim streamside landscape. The results are as follows; 1) The waterlogged prevention frame revetment appeared to be stable despite of two big floods. The materials used for the revetment were not eroded on the water attacking point. Thus, we confirmed the effect of scour prevention of the frame work. 2) The effects of the frame revetment on the water quality appeared to be good for the surrounding environment. Dissolved Oxygen(DO) was higher about $0.4{\sim}0.6mg/{\ell}$ at the frame revetment than that of the main stream flow. pH value was lower about 0.4~0.5. Electric Conductivity(EC) showed lower about $0.8{\sim}1.1{\mu}s/cm$. at submersion prevent frame than the low-flow of the stream. Turbidity was lower about $0.6{\sim}1.2mg/{\ell}$. 3) As the effects on ecological and environmental conditions, we discovered a number of carassius auratus and Zacco platypus in the frame revetment area. Also, sympetrum balteata, coenagrionidae was observed frequently. 4) The plant growth did not appear to tumble or wither despite of two big floods. The visual rating of plant growth was evaluated as medium (around 5 point) 5) The landscape analysis derived four factors(i.e. the harmony, the variation, the flexibility and the provincial characteristics) from the factor analysis.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.995-1000
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• 2010

To investigate the relationship between polychlorinated byphenyls (PCBs) sources and concentration level in sediment, total 63 sediment samples with three-time sampling at one site were measured at 21 sites in Nakdong River. As a result of analysis, total concentrations and toxic equivalent (TEQ) concentration of Dioxin-like PCBs were ranged from 3.0 to 6,600 pg/g-dry with a mean value of 440 pg/g-dry and

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.166-173
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• 2017

Morphological and population characteristics of the Cottus koreanus were investigated at Hoam stream from October 2015 and April 2016. This is the first record on C. koreanus not only from Hoam stream (the upstream region of Daejong stream, Gyeongsangbuk-do Gyeongju-si Yangbuk-myeon Hoam-ri) but also from the stream flowing into the Samcheogosip stream, in the southern part of East Sea, Korea. The distribution of C. koreanus ranged from Girim temple to Yongyeon waterfall, about 1.2 km, and the water surface were about $3,600m^2$. The population size was assumed to 1,656 individual number, 46 object per $100m^2$. The morphometric characteristics of C. koreanus in the Hoam stream and the Han river are very similar except that the population at Hoam stream shorter head length, ventral fin ray length, pectoral fin ray length and mouth width when compared with the population at Han river. Other than that, the two populations showed the same meristic characters. Frequency analysis of total length indicated that the group with 40~59 mm in total length was one year old, the 60~79 mm was two years old, and the group over 80 mm was three years old. The average number of eggs in the ovaries was estimated as 361 (239~468) per matured female. The number of matured eggs size in ovaries was $2.6{\pm}0.21$ (23.~3.1) mm and this species was large eggs type. Calculation of the length-weight relation of C. koreanus showed the value of constant a as 0.00001 and b as 3.01, and the Condition factor (K) was 1.26 an on average.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.202-209
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• 2018

The purpose of this study was to analyze the correlation between the effluent of a sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. Flow and water quality data, such as BOD, COD, SS, T-N, and T-P data, for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS, and T-P were correlated positively with the river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluents and downstream streams, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between the river flow rate and the water quality factors (COD, SS, TP) was high at river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.527-536
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• 2007

In this study, we applied 10-metric health assessment model, based on the Index of Biological Integrity (IBI) during 2006 in the Changwon Stream, which is located in the Changwon city, Gyeongnam province, S. Korea, and then compared with water quality data. The Index of Biological Integrity (IBI) in the Changwon Stream varied from 18 to 38 in the watershed depending on the sampling location and averaged 30.3 (n=6) during the study. Analysis of tolerance guilds showed that the proportion of sensitive species was 13%, but tolerant and intermediate species were 34% and 53%, respectively. Qualitative Habitat Evaluation Index (QHEI) averaged 43.3 (range: 65-104, n=6) indicating non-supporting condition, based on the criteria of U.S. EPA (1993). Values of QHEI showed a typical longitudinal decreases from the headwater reach to the downstream location, except for Site 1 with a low QHEI value by artificial habitat by concrete construction. Minimum QHEI was found in Site 4 where fish diversity was minimal. Conductivity increased continuously along the gradients and especially showed abrupt increases in the downstream sites along with turbidity. Stream ecosystem health of IBI matched to the values of QHEI except for S6. Low IBI values in the sites 4 and 5 was considered to be a result of combined effects of chemical pollutions and habitat degradations. Our results support the hypotheses of Plafkin et ai. (1989) that physical habitat quality directly influences the trophic structure and species richness, and is closely associated with IBI values.