• Proceedings of the Korean Society of Environment and Ecology Conference
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• autumn
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• pp.46-50
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• 2004

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.164-171
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• 2007

This experiment was conducted to investigate heavy metal speciation and bioavailability from soil to the edible parts of water dropwort near industrial complex. The soils and water dropwort were collected from the paddies cultivating water dropwort(10 sites), stream sediments(5 sites), and background soils(3 sites) near industrial complex. The total concentrations of Cd Cu, and Ni were higher than those of permissible level for soil contamination(Cd 3, Cu 100, Ni $50mg\;kg^{-1}$ in soil) suggested by Kloke(1979). Dominant chemical forms of Cd in paddies cultivating water dropwort and stream sediments were exchangeable form(49.1-56.3%), and those of Cu, Zn, and Ni were Fe and Mn oxide bound and residual forms. The mobility factor of heavy metals in paddies cultivating water dropwort and stream sediments was in the order Cd>Zn>Ni>Cu>Pb, specially, the mobility factor of Cd (62-72%) were relatively higher than that of other metals in soils. The total concentrations of Cd in soils showed significant positive correlation with the ratios of exchangeable and Fe and Mn oxide bound forms, while correlated negatively with residual form. Heavy metal contents in root parts were higher than those in top parts of water dropwort. The bioavailability of water dropwort varied considerably between the different parts and heavy metals. Cd, Cu and Ni contents in water dropwort were correlated with each fractions in soils. Specially, the exchangeable form of Cd and Ni in soils showed significant positive correlation with the those contents of water dropwort.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2015.08a
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• pp.107-112
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• 2015

• Journal of Ecology and Environment
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• v.43 no.3
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• pp.314-319
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• 2019

Background: The dramatic worldwide decline in the butterfly species Leptalina unicolor (Bremer & Grey) is largely the result of continuous habitat decline and disturbance by humans. The discovery of a narrow habitat in riverside wetlands utilized by L. unicolor raises the hope that such restricted key areas could be rather easily protected. Results: Here, we explain the environmental variables and habitat characteristics that primarily influence the distribution of L. unicolor discovered at the riverside areas along the Geum River. L. unicolor larvae were found at 9 of 13 study sites, and their abundance was strongly positively correlated with plant biomass. Our investigation showed that among four plant species (Miscanthus sinensis, Spodiopogon cotulifer, Setaria viridis, and Imperata cylindrica), L. unicolor larvae were the most abundant on the leaves of M. sinensis. They were not abundant on the leaves of S. cotulifer, S. viridis, or I. cylindrica. Interestingly, the number of L. unicolor larvae was positively correlated with the coverage area ($m^2$) of M. sinensis (F = 41.7, $r^2=0.74$, P < 0.0001). Conclusions: It appears that water (e.g., wetlands, ponds, and watersides) located along the riverside areas along the Geum River is important for the constant maintenance and conservation of L. unicolor. This is based on the habitat characteristics (water preference) of M. sinensis, which is used as a habitat by L. unicolor larvae. However, the waterside is dry and terrestrialization is in progress owing to the decreased water levels and water supply caused by an opened weir. Hereafter, this area will likely require management to secure a stable habitat for L. unicolor.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.113-118
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• 2008

[ $6{\sim}13mg/L$ ] base water concentration on monthly BOD has been kept at the Geukrak bridge point for this research target and it indicates the water quality under the existed rank. Due to this present condition of water quality, the demage of ecology from the upper stream to the lower one of the bridge could be conjectured. Moreover, nonstructural extinction of the ecology seems to have gotten worse between both the streams of Yeoungsan River. On this research, eco-corridor between the upper stream and the lower stream of the river should be ensured, the ecological demage needs to be cut off, a dispersed discharge method which the existed method of the 1st sewage plant in Gwangju was enhanced to should be inducted for the procuring of various water ecosystem, and the conditions by the scenario suggested from this research could be applied to a water quality model. then, analysis the improvement effect of the water quality adjacent the river. From the test result, Case3-Type1 scenario is thought to be the best one. From the test result with Case3-Type1 when the concentrated discharge was never done, 0.07 mg/L of BOD concentration was increased at the lower stream where Yeoungbon B point (Haksan Bridge) is but the water improvement effect of $0.24{\sim}2.87mg/L$ is thought to have been done at the area of water deterioration.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.185-199
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• 2023

This study aimed to predict the effects of water ecology on the supply of hydrothermal energy to model a housing complex in Eco Delta Smart Village in Busan. Based on the results, engineering measures were recommended to minimize problems due to possible temperature variations on the supply of hydrothermal energy from the river. The current distribution of fish, benthic macroinvertebrates, and phytoplankton in the Pyeonggang Stream was monitored to determine their effects on water ecology. In the research area, five species and three families of fish were observed. The dominant species was Lepomis macrochirus, and the subdominant species was Carassius auratus. Twenty-five species and 21 families of benthic macroinvertebrates were found. The distribution of aquatic insects was poor in this area. The dominant species were Chironomidae sp., Lymnaea auricularia, Appasus japonicus, and Caridina denticulata denticulata in February, May, July, and October. Dominant phytoplankton were Aulacoseira ambigua and Nitzschia palea in February and May. Microcystis sp. was dominant in July and October. The health of the ecology the Pyeonggang Stream was assessed as D (bad) according to the benthic macroinvertebrate index (BMI). Shifts in the location of the discharge point 150 m downstream from intake points and discharge through embedded rock layer after adding equal amounts of stream water as was taken at the beginning were suggested to minimize water temperature variations due to the application of hydrothermal energy. When the scenario (i.e., quantity of water intake and dilution water, 1,600 m³/d and water temp. difference ±5 ℃) was realized, variations in water temperature were assessed at -0.19 ℃ and 0.59 ℃ during cooling and heating, respectively, at a point 10 m downstream. Water temperatures recorded at -0.20 ℃ and 0.68 ℃ during cooling and heating, respectively, at a point 10 m upstream. All stream water temperatures after the application of hydrothermal energy recovered within 24 hours. Future work on the long-term monitoring of ecosystems is suggested, particularly to analyze the influence of the water environment on hydrothermal energy supply operations.

• Toxicological Research
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• v.17
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• pp.319-321
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• 2001

Taihu Lake is a major water source for part of Yangtze Delta, which is one of the most urbanized and economically prosperous areas in China. In last couple of decades, some parts of the lake were highly polluted due to eutrophication. This study analyzed dioxin-like potential and mutagenic potential in surface water samples from Taihu Lake. The samples were prepared by XAD-2 resin procedure. A batch of biological assays, including dioxin-like potential microassay with the rat hepatocyte cell line H411E, and Ames test was employed in the research. Results showed that jour water samples have high content of dioxin-like biological potential, the highest activity TEQ to 2,3,7,8-TCDD was 48 pg/ι in sample 1. The mutagenic effect with reading-frame shifting mechanism was confirmed in 3 of 4 samples. The effective sewage treatment facilities and reliable monitoring surveillance system are urgently needed for this area.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.247-254
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• 2015

Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.311-321
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• 2018

The purpose of this study is to investigate effect of stream channel naturalness on ecological health by using environmental factors and Fish Assessment Index (FAI) in the Han River of South Korea. These samples and data have been released from the research project titled Stream/River Ecosystem Survey and Health Assessment, which was conducted in 444 sites in the Han river watershed from 2008 to 2016. All samples were classified into five groups according to a degree of morphological changes of stream. Water chemistry analyses indicated a decline in water quality by decreasing stream channel naturalness, it is assumed that channelized stream was vulnerable to aquatic pollution compared to the natural meandering stream. In the result of frequency of dominant species, sensitive species and insectivore such as Zacco koreanus, Rhynchocypris kumgangensis and Pungtungia herzi were frequently dominated in the natural meandering stream while tolerant species and omnivores such as Carassius auratus and Cyprinus carpio were more dominated in the channelized streams. The FAI in the channelized stream shows decline to average of $46{\pm}25$ compared with that of the natural meandering stream ($80{\pm}20$). The decrease in FAI was highly influenced by changes in matrixes of fish assemblage structure such as number of sensitive species (M3), portion of omnivores (M5) and insectivores (M6). Moreover, annual average FAIs from 2008 to 2016 were significantly correlated with water chemistry, especially TN, TP and BOD ($r^2=0.59$, p<0.0001). Taken together, all the results suggest that the stream channelization could negatively impact on the water quality and fish assemblage structure, leading to degradation in aquatic ecosystem health.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.529-536
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• 2017

The study is intended to investigate the proliferation of whitening, the impact of climate change (sea temperature rise) on the proliferation of whitening, and the reproduction and growth of crustose coralline algae, which causes the whitening, in the coast of Jeju Island. The size of the whitening-affected area in the coast of Jeju was 2,931ha in 1998 and increased to 4,541ha in 2003. The whitening occurred mainly in the southern coast of Jeju in 1998 but spread across the whole coast of Jeju by 2003, except in the coast of Jocheon-eup (eup refers to an administrative district in Korea) and Gujwa-eup. The average sea water temperature in February from 1992 to 2004 was $15.1^{\circ}C$ in the whitening affected area and $13.9^{\circ}C$ in the marine forest area, showing a clear difference, but there was no difference in the average temperature in August. The long-term (37-year period) average of the sea temperature was $15.3^{\circ}C$ in the whitening affected area and $14.1^{\circ}C$ in the marine forest area, showing $1.2^{\circ}C$ higher in the whitening area. The annual rate of sea temperature rise was $0.038^{\circ}C$ in the whitening area and $0.024^{\circ}C$ in the marine forest area, indicating the higher long-term variation of sea temperature in the water affected by whitening. The results indicate that the continuous increase in winter water temperature due to climate change is expanding proliferation of whitening in the Jeju island.