• Water Engineering Research
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• v.5 no.3
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• pp.147-156
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• 2004

Recently, the population growth, industrial and agricultural development are rapidly undergoing in the Lower Rio Grande Valley (LRGV) in Texas. The Lower Rio Grande Valley (LRGV) composed of the 4 counties and three of them are interesting for Non-point and point source pollutant modeling: Starr, Cameron, and Hidalgo. Especially, the LRGV is an intensively irrigation region, and Texas A&M University Agriculture Program and the New Mexico State University College of Agriculture applied irrigation district program (Guy Fipps and Craig Pope, 1998), projects in GIS and Hydrology based agricultural water management systems and assessment of prioritized protecting stream network, water quality and rehabilitation based on water saving potential in Rio Grande River. In the LRGV region, where point and non-point sources of pollution may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to determine the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern with water quality related to pesticides, fertilizer, and nutrients within LRGV region. The GIS technique is widely used and developed for the assessment of non-point source pollution in LRGV region. This project shows the losses in kg/$km^2$/year of BOD (Biological Oxygen Demand), TN (total Nitrogen) and TP (total phosphorus) in the runoff from the surface of LRGV.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.73-83
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• 2013

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a "good condition" by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species ($P_{TS}$) and sensitive species ($P_{SS}$) to water quality showed that the proportions of $P_{TS}$ had positive linear functions with nutrients, and that the $P_{SS}$ had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.155-165
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• 2014

In this study, using a complex of physical, chemical, and biological evaluation factors, the ecological vulnerability to climate change were evaluated at each river in the Nakdong river basin. First, runoff, sediment rate, and low flow discharge changes according to AIB climate change scenario using the SWAT model were simulated. Also, for the assessment of chemical and biological factors, 48 points that water quality monitoring sites and ecological health measurement points are matched with each other was selected. The water quality data of BOD and T-P and the biological data of IBI and KSI in each point were reflected in the assessment. Also, the future rise in water temperature of the rivers in Nakdong river basin was predicted, and the impact of water temperature rise on the fish habitat was evaluated. The top 10 most vulnerable points was presented through a summary of each evaluation factor. This study has a contribution to river restoration or management plan according to the characteristics of each river.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.151-160
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• 2009

In order to use fundamental data for conservation of species diversity and stream health with dam development, fish investigation in up- and downstream of Pyeonglim Dam was seasonally conducted in 2007~2008. In addition, data of water qualities, investigated for environmental impact assessment, were used to determine a water quality standard level in Pyeonglim Stream, and it revealed that water environment condition was good in the stream. During the study period, a total number of fish caught from the 4 study sites was 5,449 representing 9 families 25 species, and there were 8 Korean endemic species (32.0%) including Rhodeus uyekii, Squalidus gracilis majimae, and Microphysogobio yaluensis. Two species of Zacco temminckii (37.5%) and Zacco platypus (26.3%) were dominant and subdominant in all sites. There were few individuals of the $2^{nd}$-class endangered species (Sand lamprey, Lampetra reissneri) and the introduced species (Bluegill, Lepomis macrochirus), found in the upstream of the dam. and further investigation for conservation of the endangered species and for prevention of the introduced species is needed in future. With fish fauna and multi-metric health assessment model in each sampling attempt, index of biotic integrity(IBI) was evaluated and it resulted mostly in good(26~35) and excellent(36~40) condition in all sites. The results indicate that it is very important to study not only environmental impact assessment with fish composition but also stream health assessment in order to conserve healthy aquatic ecosystem.

• Advances in environmental research
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• v.9 no.3
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• pp.151-160
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• 2020

Water quality demonstrates physical, chemical and biological characteristics of water. The quality of surface and groundwater is currently an important concern with population growth and industrialization. Over exploitation of water resources due to demand is causing the deterioration of surface water and ground water. Periodic water quality testing must be carried out to protect our water resources. The present research analyses the spatial variation of surface water and groundwater in and around the lakes of Hyderabad. Twenty-Seven lakes and their neighboring bore water samples are obtained for water quality monitoring. Samples are evaluated for specific physico-chemical parameters such as pH, Total Dissolved Solids (TDS), Cl, SO₄, Na, K, Ca, Mg, and Total Hardness (TH). The spatial variation of water quality parameters for the 27 lakes and groundwater were analysed. Correlation and multiple regression analysis were carried out to determine comparative study of lake and ground water. The study found that most of the lakes were polluted and this had an impact on surrounding ground water.

• Journal of Environmental Science International
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• v.32 no.2
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• pp.99-120
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• 2023

The community structure of benthic macroinvertebrates in Upo wetland was identified, and the biological water quality was evaluated. In addition, through statistical analysis of current and literature data, ecological changes over time were evaluated for each wetland. Benthos were quantitatively collected in March, June, and September of 2020 and 2021, and 4 phyla, 5 classes, 16 orders, 42 families, 81 species and 3,406 individuals were identified. In the functional feeding group of Upo wetland, predators were dominant with 34 species (45.95%) and 1,504 individuals (41.84%). In the habitual dwelling group, sprawlers and swimmers showed the highest proportion in the number of species and individuals. Average biological indices in Mokpo and Upo were the highest and lowest, respectively, and it is considered that Mokpo maintains the healthy ecosystem for benthic macroinvertebrates. Community stability was high in Upo, and other wetlands are thought to be stabilizing. The ecological score of benthic macroinvertebrate community is considered to be more suitable index among three biological water quality evaluation indices for the environmental evaluation of Upo wetland. The evaluation results on changes in environmental quality showed that Upo has stable ecosystem without significant change, Mokpo and Sajipo have significant increases in some indices.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.361-371
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• 2005

The objective of study was to diagnose integrative ecological health of Daejeon Stream, one of the tributaries of Guem River, during May 2004 ${\sim}$ April 2005. The research approach was primarily based on a Qualitative Habitat Evaluation Index (QHEI) and the Index of Biological Integrity (IBI) using fish assemblage. These outcomes were compared with conventional chemical dataset. For the experiment, four sampling sites were chosen from Daejeon Stream and long-term water quality data during 1995 ${\sim}$ 2004 (obtained from the Ministry of Environment) were analyzed in the spatial and temporal aspects. For the biological health assessment, we developed a stream health assessment model (SHA model) far regional applications. We found that current water quality conditions, based on the COD, BOD, TN and TP, were enhanced by 1.6 ${\sim}$ 5.3 fold over the period of 1995 ${\sim}$ 2004 and that the parameters showed a typical longitudinal decline from the upstream to downstream reach. The differences of water quality between the two reaches were more than 4.4 times, indicating a large spatial variations within the stream. The health conditions, based on the SHA model, averaged 23 and varied from 20 to 26 depending on the sampling stations. Values of the QHEI varied from 39 (Poor condition) to 124 (Cood condition)and values of QHEI in the reach of S2 ${\sim}$ S4 had significantly lower than in the headwater site (S1). Also, biological stream health, based on the criteria of US EPA (1993), was judged as 'Poor condition', in the S4 where TN, TP, BOD and COD were highest. In the meantime, maximum value of SHA (26) was found in the upstream reach (S1) where the water quality and QHEI were best. We also found that compositions of sensitive species showed a linear function with water quality conditions and this pattern was evident in the tolerant species. Thus, the biological stream health, based on the SHA model, matched well water chemistry. Overall outcomes suggest that the biological health impact was a function of chemical degradation and physical habitat quality in the stream.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.127-140
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• 2010

This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Nonsan Stream and Yanghwa Stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into two types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. Nowadays, The fundamental goal of the river environment restoration enterprise is the rehabilitation or the restoration of the characteristic the river scenic or environment. For instance, The Channel habitats which has physical nature environment such as flat, speedy rapids, or closed-channel wetland, pool are constructed by artificial, Consequently, make them autogenesis smoothy eco-environment. However, the river environment are controlled not only physical environment, but it also need reasonable the quality of the water to compose smoothly. Finally, understanding what influence are effecting on physical habitat environment which are made by natural factors to water quality are very important factor for the river environment restoration enterprise Therefore, In this research, we are targeting to a basin to investigate the environment of the physical channel habitat and evaluate the changing of the water quality. This results will be a important characteristic that can judge the physical habitat and reciprocality connected to the water quality or adequacy of restoration technology. Therefore in this study, as a step to quantify functions and values of habitats and definite factors to perform habitat, we selected a representative stream of sand-stream, gravel-stream to classify habitat characteristics and quantified the physical, chemical, biological characteristics.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.11-22
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• 2011

This study was established to build and suggest the Ecological Performance Standards for replaced wetlands as the mitigation strategies for the construction projects. The request performance and assessment factors and standards were derived by bibliographic review and verified by the field survey for the reference wetlands. And the weights for each factor were derived by AHP(Analytical Hierarchy Process) method. The results are as follows : 1) Assessment factors were induced by in-depth research of many wetland assessment models and benchmarks evaluated ecological functions. This study proposed final 12 assessment factors through ecological specialist and experts interviews added with literature analysis. 2) 10 natural wetlands were selected as Reference Wetlands as the measure to propose assessment factors and assessment criteria. Those reference wetlands are well-conserved inland natural wetlands classified to the one having worthy to conserve (grade "high") according to RAM(Rapid Assessment Method). Reference wetlands chosen by the study are Parksilji, Jeongyangji, Mulkubi, Bawineupkubi, Jilnalneup, Jinchonneup, Doomoso, Haepyung wetland, Whangjeong wetland, and Whapo wetland. The research developed assessment criteria for the performance assessment factors based on several explorations of the reference wetlands. 3) "Requiring performance" of replaced wetlands is defined as "to carry out similar or same ecological functions provided by natural wetlands", in overall. The detailed requiring performances are as follows; ${\bullet}$ to play a role of wildlife habitats ${\bullet}$ to have biological diversity ${\bullet}$ to connect with other ecosystems ${\bullet}$ to provide water environment to perform good ecological functions 4) The assessment factors for required performance are categorized by wildlife habitat function, biological diversity, connectivity of adjacent ecosystem, and water environment. Wildlife habitat category is consisted of wildlife habitat creation, size of replacement wetland, and site suitability. Biological diversity category contains the number of plant species, the number of wildlife species, and number of protected species as the sub-factors. Connectivity of adjacent ecosystem is comprised of wildlife corridor, green network and distance from other ecosystem. Finally, water environment make up with water quality, depth of water body, and shape of waterfront. 5) Finally, every assessment factors were verified and weighted by the AHP methods and the final standards were proposed. The weights of factors of requiring performance suggested as habitat (0.280), connectivity (0.261), diversity (0.260), hydraulic environment (0.199). And those of detailed sub-factors are site suitability (0.118), protected species (0.096), distance to neighbor ecosystem (0.093), habitat creating (0.091), green corridor (0.090) etc.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.643-655
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• 2011

This study addresses the periphytons along the Bukhan river stream and examines the biological indices that represents the river and estimate water quality assessment. Bukhan river in 4 major watershed streams (Bukchon-Hangeychon, Narinchon, Inbukchon, and Soyang river) was selected in 9 points. Land use pattern along the streams showed marked differenced in agriculture areas and forest areas. Lower Soyang streams showed blue-green algae and green algae also appeared in evenly pattern. Thus, the pollution source, biomass and distribution are somewhat correlated, and BOD, SS, biodiversity, and evenness showed a similar pattern. This situation can lead to conclusion of oligotrophic lake with good condition. Therefore, current biological index and is not so desirable for stream degree standard water quality and nutrient level.