• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.145-157
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• 2000

The Water Quality Analysis Simulation Program 5 (WASP5) and HEC-2 models have been coupled and applied to find the possibility of simulation of long-term river water quality variation. The EUTR05 as a simulator of water quality simulation in WASPS model was used to simulate the water quality variables in the downstream of Geum-River from Daechung multi-purpose dam during the dry period. The water quality and flow rate conditions have been measured at the stage measurement stations located in the downstream of Geum-River from Daechung dam in December, 1998 and January and March, 1999. The water quality simulation model was calibrated with January data of 1999, and verified with December data of 1998 and March data of 1999. The trend of longitudinal variation of water quality variables simulated by model is consistent with that of measured water quality constituents except chlorophyll-a, $BOD_5,\;NH_3-N\;and\;PO_4-P$ simulated with March data of 1999. Furthennore, the chlorophyll a concentration in the mainstream of Geum-River was simulated by changing the concentrations of $PO_4-P$ and/or $NH_4-N$ flowing into the mainstream of Geum-River from Gabcheon and Mihocheon. The variation of chlorophyll a concentration in the mainstream was almost ignorable except only when $NH_3-N\;and\;PO_4-P$ concentrations decreased by 70% flow into the mainstream from Gabcheon and Mihocheon.

• Korean Journal of Environment and Ecology
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• v.24 no.5
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• pp.556-565
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• 2010

Community analysis based on functional feeding groups of benthic macro invertebrates at Wangpi-cheon was assessed with the result of four field survey from October, 2007 to May, 2008. A total 138 species of benthic macro invertebrates in 58 families, 16 orders, 6 classes, and 4 phyla were collected during the field surveys. The result of EPT index value showed high value of 61.59% and it means that the stream ecosystem of Wangpi-cheon is very clear and healthy. In this study the functional feeding groups in Wangpi-cheon were divided into two groups. First, Scrapers and Collectors-Gathering group which is normally dominant in midstream showed higher dominance in main stream than tributary. Second, shredders group showed higher dominance in tributary than main stream like as the general characteristics of upriver. With the result of cluster analysis based on the similarity index, the study areas could be grouped into a natural area(A group) and an artificial disturbance area(B group; site 8 and 11) where embankment, bank and levee had been built near by. And also, the natural area(A group) was classified into two groups which had the characteristic of main(site 1, 2, 3, 4 and 7) stream and tributary(site 5, 6, 9 and 10) respectively.

• 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.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.288-302
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• 2017

Accurate measurement of benthic nutrient fluxes (BNF) is a prerequisite for evaluating the effect of sediments on nutrient cycle in the surface water. The intact sediment cores were collected in July 2015 at the midstream of Nakdong River. We identified pre-incubation time (6, 12, 24 hr), dissolved oxygen concentration (90, 70, 50% saturation), diffusive boundary layer thickness (0, 0.6-0.8, 1.2-1.4 mm), and incubation temperature (10, 17, 20, $25^{\circ}C$) as the most important control factors, and measured the BNF fluctuation with the variation of these factors using the laboratory sediment core incubation method. Since the chemical composition, redox condition, hydrodynamic regimes and microbial activities at the sediment-water interface were changed as a result of the alteration of control factors, sediment core incubation should be conducted under as close to the natural conditions of study site as possible, in order to produce the results similar to actual values. Relative percentage differences between two replicates were below 20% in most control factors, which showed satisfactory precision for strict compliance with the experimental conditions and procedures. In the further studies, we will compare the results of core incubation with those of in situ measurements to confirm the accuracy of the sediment core incubation method.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.43-56
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• 2005

This study was conducted to examine the inhabitation of wild birds at the World Cup Park and to offer the Park ecological management data. Land use md actual vegetation were examined to analyze the inhabitation of wild birds. Characteristics of bird communities were analyzed by dominance, density, diversity index and guild concept. You compare inhabitation before and after the Park was built. We classified the land use and actual vegetation into twenty-six types. Robinia pseudoacacia dominated the study area. Pyeonghwa Park and Nanji-cheon Park were simple-layer structures composed of alien woody species. The observed birds after the World Cup Park included 33 families 77 species, and 9,751 individuals. Among Wild Life types, the shrub and bush type was dominant. There were 26 species of resident birds, 20 species of summer visitors, 18 species of winter visitors, and 12 species of passage migrants. The following numbers of species and individuals were observed: in Hanul park, 38 species, 3,151 individuals; in Noul park, 45 species, 2,061 individuals; in Nanji-cheon park, 42 species, 2,742 individuals; in Pyeonghwa park, 29 species, 875 individuals; and in Maebongsan(Mt.) area, 35 species, 922 individuals. Species diversities for each area were as follows: Noul park, 2.613; Hanul park, 2,301; Nanji-cheon, 2.228; and Pyeonghwa park, 2,019; and each season: summer, 2.652; spring, 2.650: winter, 2.561; and autumn 2.176. The diversity of species increased from 1.135 in 1994 to 2.324 in 2001. We recommended that the park be differented into different ecological areas in order to encourage the appearance of wild birds at the World Cup Park. The management area was divided into three districts(conservation area, preservation and restoration area, use area). The conservation area was established to the west of a waste landfill and in the downstream area of NanJi-cheon, the preservation and restoration area was established in the midstream area of Nanji-cheon, and the use area was established in the buffer zone of Pyeonghwa Park and the Nanji pond greenspace.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.424-431
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• 2014

Analysis of the fish community in Yeongwol Hanbando wetland in Korea was investigated from April to October 2012. During the survey period, total 33 species belonged to 10 families and 7,107 individuals. There were 18 Korean endemic species (52.94 %), including to Acheilognathus signifer. Also, the dominant species were Zacco koreanus at St. 1, 2, 3 & 5, as well Acheilognathus signifer at St. 6, and Pseudopungtungia tenuicorpus at St. 7, respectively, and these species were inhabited in the midstream. But at St. 4, Carassius auratus was dominance, so there appeared to characteristics of downstream or lentic habitat. Also, according to the similarity analysis on fish species and their individuals in each sites, they were divided into three major groups (A,B and C). Among them, group C (St. 4) showed the special inverse characteristics as a stagnant pond. unlike the river branch (group A) and anthropogenic disturbances receiving stream point (group B), Therefore, the ecosystem of Yeongwol Hanbando wetland is considered to very unique and these characteristics are not found in other stream ecosystems and it is confidently believed that the ecological value is very high.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.387-394
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• 2000

Water pollution characteristics were investigated in the Kyongan stream and major inlet parts of Paltang Reservoir from April to July, 2000. Water quality in the Kyongan stream was extremly deteriorated by treated wastewater discharge at near sewage wastewater treatment plant (SWTP) located in the upstream, and it is likely to influence eutrophication of the lower part of the stream. Water quality of the Kyongan stream showed a typical hypertrophic condition. Influxed concentrations with $NH_4$ and SRP into the main stream from SWTP were declined precipitously as water flowed toward the lower part of the stream, and chlorophyll- a explosively increased in the midstream. Average concentrations of $NH_4$, SRP and chlorophyll-a in the main stream were $1,343\;{\mu}g\;N/l$, $1,779\;{\mu}g\;P/l$ and $188\;{\mu}g\;l$, respectively. Particularly, phosphorus load was very high, and its influence on the algal growth stimulation was remarkable. In comparison with the water quality inflowing into Paltang Resevoir, pollution status of the Kyongan stream was more worse than that in the Pukhan River and the Namhan River. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate eutrophication of Paltang Reservoir, and requires further necessary controls of inorganic phosphorus loading.

• Korean Journal of Environmental Biology
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• v.31 no.3
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• pp.180-188
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• 2013

The objectives of the study were to analyze chemical water quality and fish community structures in the downstreams of Geum River during 2004~2005. Water quality parameters showed that ionic dilution was evident during July~August due to a rainfall and river runoff by Asian monsoon. Mean concentrations of BOD showed a seasonal variation and were greater in the downstream than in the midstream. The total number of fish species observed was 34 (11 families) and 30.3% of them was Korean endemic species. The dominant species with > 20% of the total were Zacco platypus (25.9%) and Microphysogobio jeoni (21.5%) in the river. Exotic species observed was only one species, Carassius cuvieri with relative abundance of 1.8%. According to the structure analysis of fish community, species richness index was highest (3.714) in S6 and lowest in S4 (1.961), while species diversity index was highest in S2 (1.01) and lowest in S5 (0.507). Tolerant species dominated the fish community (49%), and the sensitive species were rare (4.4%), indicating a biological degradation of ecosystem. In the mean time, omnivore species was composed of 49% in the fish community and insectivore species was nearly same with the proportion of the omnivores.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.34-40
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• 2004

This study was conducted to get some vegetation information and to find out a way to conseue the ecosystem in the Dongjin River. The riparian vegetation was investigated by Zurich-Montpellier school's method from June 2001 to March 2002. The number of riparian plants were 73 families, 188 genera, 238 species, 33 varieties or 272 Taxa in Dongjin River. The characteristics of life farm spectra were 97 therophytes (35.7%), 78 hydrophytes (28.7%), 41 hemicryptophytes (15.1%) 22 geophytes (8.1%), and 12 chamaephytes (4.4%). The riparian vegetation was identified 8 plant communities (Potamogeton brechtoldii, Hydrilla verticillata, Ceratophyllum demersum, Potamogeton malaianus, Phragmites japonica, Persicaria thunbergii, Cardamine scutata, Persicaria hydropiper) in upstream, 4 plant communities (Zizania latifoliar, Phragmites communis, Persicaria thunbergii, Humulus japonicus) in midstream and 8 plant communities (Hydrocharis dubia, Ceratophyllum demersum, Trapa japonica, Zizania latifolia, Paspalum distichum, Phragmites communis, Pericaria thunbergii, Amphicarpaea edgeworthii) in downstream of the Dongjin River.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.244-250
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• 2000

Algal growth potential (AGP) bioassay were conducted to assess the water quality and fertility in the Kum River from March 1998 to June 1999. AGP values were always the highest at the conjuction site of the Kapchon, which is a tributary of the Kum River. Average value of AGP by Microcystis aeruginosa in the main river and tributary was 17.0 mg dw/l, 48.3 mg dw/l, respectively. AGP values decreased towards the lower part of the river and consisted in the water quality or nutrient analysisresults. Among the tributaries, AGP of the Kapchon, Mihochon and Soksongchon were relatively high, and the average value was 161.2, 50.3 and 125.6 mg dw/l, respectively. AGP value in the Yukuchon was lowest among the study stations with <2.7 mg dw/l. Water quality in the lower part of the Kum River deteriorated in drought season, and the AGP values of this season were higher than those in other seasons. Based on correlation analysis between AGP results and nutrients, limiting nutrient appeared to be P because SRP (r = 0.99) was higher than other nutrients, and N uptake in algal growth was preferred by $NH_4$ rather than $NO_3$. The variation of AGP was different according to localities and seasons, and it was related to nutrient fluctuation in the inlet tributary. Water quality status according to AGP was assessed to be eutrophic.