• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.432-441
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• 2014

April, 2005 to October, 2013. The collected species during the survey period were 17 species belonging to 6 families. Dominant species was Zacco koreanus(Relative abundance 59.9%) and subdominant species Pungtungia herzi(8.5%). Korea endemic species were 12, including Coreoleuciscus splendidus. The species of Hemibarbus mylodon was identified as natural monument, and Pseudopungtungia tenuicorpa and Gobiobotia brevibarba were endangered species. Water quality assessment of Gapyeong Stream, had lately maintained the rating of "very good" for nine years, based on the Ministry of the Environment standards notice. It was found that there was a tendency for populations which is Coreoperca herzi carnivorous species decreases, increases omnivorous species Zacco platypus. As a result of community analysis, dominant index was 0.58~0.86, diversity index was 0.94~1.77 and richness index was 0.99~2.39. As a result of using the Rarefaction curve, were analyzed occurrence species expected each year, number of species is estimated from a sample of 151 individuals, up to 12(2005) was at least 5(2007) species. The regression coefficient (b) in relation to length-weight on Z. koreanus population were annual average $3.29{\pm}1.11$, condition factor slope $0.0034{\pm}0.0021$, which maintained good growth condition and stabilized population.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.686-694
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• 2012

This study was conducted to investigate that affect benthic macroinvertebrates for installed erosion control works at a mountain torrential stream. The survey was carried out six times from April 2007 to October 2008 at two points where erosion control works were installed and at a control point in the upstream with no such works. Variations in the community structure and cluster of benthic macroinvertebrates and ecological water quality were analyzed in the survey. From the six times survey, the identified benthic macroinvertebrates were 6,922 individuals belonged to 27 species, 24 families, 13 orders, 6 classes and 4 phyla. As the average results of three surveyed sites, the dominant species was Gammarus sobaegensis of Amphipoda. The species diversity index(H') showed the highest as 1.47 at Site 2 of the fourth survey and the lowest as 0.24 at Site 2 of the sixth survey. The evenness Index(EI) showed the highest as 0.823 at Site 2 of the fourth survey and the lowest as 0.194 at Site 1 of the fifth survey. The richness index(RI) showed the highest as 2.794 at Site 1 of the first survey and the lowest as 0.291 at Site 2 of the sixth survey. The ecological score of benthic macroinvertebrate community(ESB) and individual of EPT-group were declined during the survey period. The functional feeding group(FFG) showed the highest SH types during the survey period.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.73-84
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• 2023

The objective of this study was to evaluate biodiversity and natural habitat environment of freshwater ecosystem. Our aim was therefore to produce a set of biodiversity and habitat indicators based on multi-parameters of water quality and biodiversity by analyzing the characteristics of the results by indicators. We selected four indicators a) anthropogenic disturbance, b) habitat diversity, c) biodiversity, d) ecosystem structure. The fishes cohabiting with Brachymystax lenok tsinlingensis were Rhynchocypris kumgangensis and Zacco koreanus. As a result of the anthropogenic disturbance evaluation, it was analyzed that vegetation embankment showed a more stable environment in the tributary than the main stream, and other disturbance was not confirmed As a result of the habitat diversity evaluation, it was analyzed that habitat evaluation index showed a high score of 200 more on average, showing an optimal habitat condition. As a result of the biodiversity evaluation, it was analyzed as a clean habitat condition with a high proportion of sensitive species, abundant dissolved oxygen, and little pollutants. As a results of the ecosystem structure, the ecological health condition metrics and appearance of endangered species showed large score deviation, but it was analyzed that the stream ecosystem health was generally excellent. There was a slight correlation between the habitat environment and the results of the nature habitat evaluation according to the appearance of the B. lenok tsinlingensis.

• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.229-241
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• 2023

Microphysogobio rapidus is designated as endangered species class I by Ministry of Environment, and its distribution and population have been gradually declining, and it is now limited to the Nam River and some tributary streams of the Nakdong River Watershed. For the restoration of this highly endangered species, it is important to identify the causes of the decline and establish appropriate restoration plans. However, due to lack of basic data and ecological research, most steps are stagnant. Therefore, in this study, we identified the differences in the physical, biological, and sociological habitats between current and past distributed sites through field surveys and literature reviews. As a result of the field survey, there were differences in conductivity between the current and past distributed sites, and fish communities were also showed differences. The literature data also showed that the physico-chemical values of the past distributed sites were generally unfavorable, which generated negative consequences on biological factors. In particular, the effects of urbanization were found to be a major factor affecting the habitat of M. rapidus. Habitat stabilization is crucial for the recovery of this endangered species. However, in the past distributed sites, disturbances such as stream development and weir construction have altered streams physico-chemically and result in changes of M. rapidus. Therefore, a comprehensive plan that considers both stream connectivity and water quality is needed to manage and restore the habitat of M. rapidus.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.109-118
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• 2000

The dynamics of inorganic nutrients and phytoplankton population were examined at eight stations of Shihwa Reservoir, which situated near the cities newly constructed and the industrial complex of West-sea in Korea, from January to December 1999. Among environmental factors, average concentration of $NH_4$, SRP and SRSi were $522.7\;{\mu}g\;N/l$, $9.8\;{\mu}g\;N/l$ and $0.26\;{\mu}g\;Si/l$, respectively. Water quality was extremely deteriorated by a great amount of pollutants load into inner reservoir after the event of rainfall. Nutrients concentration was suddenly decreased toward the lower part. While $NO_3$ concentration did not much varied among stations, but it was relatively high in winter season. Chlorophyll-a concentration was high at the upper part of the reservoir, with average of $37.2\;{\mu}/l$, and closely related to the fluctuation of $NH_4$, SRP and SRSi concentrations. The phytoplankton development in the water column was dominated by diatom (autumn), prasinoid (winter) and dinoflagellate (summer). Dominant phytoplankton were composed to Skeletonema costatum of diatom, Prorocentrum minimum of dinoflagellate, Chroomonas spp. of cryptomonad, Eutreptiella gymnastica of euglenoid and Pyramimonas spp. of prasinoid. The large bloom of phytoplankton at the upper zone of the Shihwa Reservoir after inflow of a seawater were consistently observed. In consequence, water quality management of the inlet stream was assessed to be very important and urgent.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.1
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• pp.40-50
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• 2011

We study the characteristic and total flux of non-point pollutants such as total suspended solids (TSS), chemical oxygen demand (COD), dissolved nutrients, total phosphorus (TP) and total nitrogen (TN) in the storm water runoff from urban streams and sewer outlets of Banweol Industrial Complex around Shihwa Lake. The concentrations of non-point pollutants were generally increased with increasing of the duration and intensity of rainfall. Mean TSS concentration of Ansan stream was higher than that of sewer outlets but mean concentrations of COD, TP and TN were approximately 2~5 times higher of sewer outlet than of urban stream. TSS showed statistically positive relationships with COD and TP but it had negative correlation with dissolved nutrients. There was a significant correlation between total flux of non-point pollutants in the storm water runoff and total basin area of each sewer outlet, showing that the highest runoff flux was observed at 3rd sewer outlet which represents the largest basin area from Banweol industrial complex. Total runoff fluxes for TSS, COD, TP and TN in this study were 187,536 kg, 17,118 kg, 922 kg, 13,519 kg, respectively. Given the basin area of sewer outlet in Banweol industrial complex which corresponds only 3% from total catchment area around Shihwa Lake, enormous amount of non-point pollutants will be entered into Shihwa Lake without any treatment. It is necessary to manage and reduce of various non-point sources and pollutants because the runoff of nonpoint pollutants during storm events should be deteriorating the water quality of Shihwa Lake. Our results provides useful informations on the development of best managements practices (BMPs) for effective implementation of total pollution loads management system of Shihwa Lake.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.252-258
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• 2017

To determine the effects of small dam on benthic macro-invertebrate community, benthic macro-invertebrates were surveyed with both quantitative and qualitative collecting methods from 4 sites at a terraced interval (3.02 small dams per 100 m) and from 5 sites at a non-terraced interval (0.96 small dams per 100 m) in upper reach of Dorim stream, Seoul. The average water flow rate was higher at the non-terraced interval (0.149 m/s) than at the terraced interval (0.043 m/s). Diptera, which prefer slow water flow or lentic habitats, appeared more abundantly in the terraced interval (78.3%) than in the non-terraced interval (32.0%)(p<.05). Ephemeroptera, which prefer fast water flow or lotic habitats, appeared more abundantly in the non-terraced interval (14.1%) than in the terraced interval (4.5%)(p=.203). There was a difference in species distribution of Trichoptera in terraced and non-terraced intervals depending on preferred environment. In the terraced interval, the occupancy ratio of gathering-collector was 1.8 times higher than in the non-terraced interval (p<.05). In contrast, filtering-collector appeared to be about 4.4 times higher rate in the terraced interval (p=.124). The evenness indexes (J′) were found to be 0.41 and 0.77, respectively in terraced area and non-terraced intervals. KSI, evaluating biological water quality, showed an average of 4.0 and 2.4 respectively in terraced and non-terraced intervals. EPT/C index, indicating the balance of the community, showed an average of 0.1 and 0.7 respectively in terraced and non-terraced intervals. It suggests that we should make small dams in order to maintain biodiversity of benthic macro-invertebrates.

• Korean Journal of Environmental Agriculture
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• v.10 no.1
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• pp.33-49
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• 1991

In order to disclose the contamination of the Mushim-Cheon by pollutants and to establish the countermeasures, the water samples collected in November of 1989(lst sample), February(2nd), May(3rd) and August of 1990(4th) were analyzed to obtain the following results : 1. The water temperatures of the seasonal samples ranged from 8.6 to 16.2, 8.3 to 25.2, 18 to 26, and 24 to 32$^{\circ}C$, in the 1st, 2nd , 3rd, and 4th samples, respectively. 2. The pHs of all the samples ranged from 6.5 to 8.5. 3. In the 3rd sample, especially, DO was observed to fall down to 0.8 ppm at the downstream of St 13, which is not allowed even for agricultural use. 4. The BOD and COD values in sewers were much higher than those in the main stream, and especially the values of St 14-A reached 107-608 and 176-635 ppm, respectively, which far exceeded the limit of 40 ppm, the allowed value for the discharges from the disposal facilities. The SS value of St 14A ranged from 142 to 1, 900 ppm, which far exceeded the limit of 70 ppm, the allowed value for the discharges from the disposal facilities. 5. It turned out that the water quality of the Mushim-Cheon flowing through Cheong Ju was more worsened at sewers than the main stream, and at the downstream than the upstream of the surveyed area. Accordingly, the sewage disposal plant and the expansion of the disposal facilities are urgently needed.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.975-982
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• 2009

The purpose of this study is to offer informations about the current conditions and basic data of stream sediments in Busan city. So we first select 14 urban streams and collect sediment samples. Then, COD, proximate analysis, volatile solid, organic carbon content and elemental analysis were conducted to determine characteristics of the sediments. Results show that COD, volatile solid, Organic carbon content, T-N of sediment are determined in the range of 1.20~75.07 mg/g, 0.19~11.54%, 0.23~34.21% and 0.76~3.46%, respectively. Analysis data of sediments were compared with USEPA sediment quality standards and ontario sediment quality guidelines. As a result, when compared with COD, volatile solid and organic carbon content values, Bosucheon and Gudeokcheon are relatively heavily contaminated than the remainder sampling sites. But when compared with T-N values, all of sites were evaluated as seriously contaminated. Finally, for the determination of the correlations between sediment COD and moisture contents, ash contents, volatile solid, total organic carbon, total nitrogen and total carbon, linear model was fitted to the data using a least-squares algorithm. As a result, Linear model was well fitted to each data with good values of the correlation coefficient (r=0.9664~0.8501).

• Journal of Environmental Science International
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• v.16 no.2
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• pp.203-210
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• 2007

The delivery load data obtained from Nakdong river basin are used for developing the model estimating the daily delivery load on the main side streams of Nakdong River. The developed model assesses the daily contamination loads of the main thirteen side streams that contribute to the main stream of Nakdong river. It is developed that the model using the simplified equation that can estimate the daily delivery loads on the side main streams of Nakdong river for a period of having no data of the water quality and flow. The developed model for estimating the daily delivery loads from the main side streams in Nakdong river basin on each item such as BOD, TN, and TP is expressed as Daily delivery load ($\frac{kg}{day}$) = Production load $(\frac{kg}{day}){\times}(1-{\alpha}){\times}(\frac{daily\;runoff}{average\;runoff\;per\;year}){\gamma}$. The estimated values obtained by using the model are almost fit to the calculated values (real data) that have been acquired from the thirteen main side streams in Nakdong river basin. The correlation coefficient values, R, that indicate the correlation between the estimated and the calculated show over 0.7 that mean the estimated values from the used model are adapted to the real data except TN values of Nam-river, Hwang-river, Gam-river, We-river. Especially, the correlation of TP values between the estimated and the calculated implies quite a creditable data to use.