• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.130-142
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• 2007

This study was to examine impacts of turbid water on fish community in the downstream of Yongdam Dam during the period from June to October 2006. For the research, we selected six sampling sites in the field: two sites were controls with no influences of turbid water from the dam and other remaining four sites were the stations for an assessment of potential turbid effects. We evaluated integrative health conditions throughout applications of various models such as necropsy-based fish health assessment model (FHA), Index of Biological Integrity (IBI) using fish assemblages, and Qualitative Habitat Evaluation Index (QHEI). Laboratory tests on fish exposure under 400 NTU were performed to find out impact of turbid water using scanning electron microscope (SEM). Results showed that fine solid particles were clogging in the gill in the treatments, while particles were not found in the control. This results indicate that when inorganic turbidity increases abruptedly, fish may have a mechanical abrasion or respiratory blocking. The stream health condition, based on the IBI values, ranged between 38 and 48 (average: 42), indicating a "excellent" or "good" condition after the criteria of US EPA (1993). In the mean time, physical habitat condition, based on the QHEI, ranged 97 to 187 (average 154), indicating a "suboptimal condition". These biological outcomes were compared with chemical dataset: IBI values were more correlated (r=0.526, p<0.05, n=18) with QHEI rather than chemical water quality, based on turbidity (r=0.260, p>0.05, n=18). Analysis of the FHA showed that the individual health indicated "excellent condition", while QHEI showed no habitat disturbances (especially bottom substrate and embeddeness), food-web, and spawning place. Consequently, we concluded that the ecological health in downstream of Yongdam Dam was not impacted by the turbid water.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.320-330
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• 2006

An integrated health of a lotic ecosystem, Cho River, was evaluated by various approaches such as conventional water quality analysis, physical assessments of Qualitative Habitat Evaluation Index (QHEI), and the bioassay of Index of Biological Integrity (IBI) durin August${\sim}$September 2005. The IBI model used in the study was based on original multivariate metric model and then modified the metric attributes of the model for the regional application. Physical habitat health, based on the QHEI, was estimated using eleven metrics. During the study, values of IBI model averaged 36, which was judged as 'fair' to 'good' conditions. Spatial variations in the model values were evident: the headwater site (S1) was estimated as 48, indicating an 'excellent' condition, and the other sites were estimated 32${\sim}$38, 'good' condition. Values of the QHEI in the all sites averaged 148, which is judged as a good condition. The QHEI values varied from 120 (fair condition) to 199 (excellent condition) depending on the location of the stream. Site 5 (S5) was estimated as 'fair${\sim}$good' condition, while Site 7 (S7) was estimated as 'excellent' condition. The biological health, based on the IBI, reflected the habitat health. However, chemical conditions in terms of pH, turbidity, electric conductivity, dissolved oxygen (DO) did not make a difference in the biological health because of minor chemical differences among the locations.

• Journal of the Korean earth science society
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• v.21 no.5
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• pp.563-582
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• 2000

Two Cretaceous(80-90 Ma) non-marine sedimentary basins, Namyang and Tando Basins, are distributed in the Namyang area, Hwaseonggun and in the Tando area, Ansanshi, Kyungki Province, Korea. The Namyang and Tando Basins are composed of 10 facies, which are pooped into 5 facies associations(FA). FA I consists of massive conglomerate facies, normally graded conglomerate facies and reversely graded conglomerate facies, which is interpreted to have been formed by laminated sandstone facies, massive conglomerate facies(channelized), which is thought to have been formed by sheet flow, stream flow and suspension sedimentation in an alluvial/braided plain environment. FA III consists of massive mudstone(pebbly) facies, laminated mudstone facies, massive sandstone facies and is interbedded by channel-fill conglomerate. It is interpreted to have been deposited by suspension settling during flooding and channel-fill deposition in a floodplain environment. FA IV consists of massive conglomerate facies, normally graded conglomerate facies, massive sandstone facies, normally graded sandstone facies, and laminated sandstone facies and is interbedded with mudstone facies. It is thought to have been deposited by debris flow and turbidity current in a fan-delta environment. FA V consists of massive mudstone facies, laminated mudstone facies, laminated sandstone facies and is interbedded by massive conglomerate bed. It is thought to have been formed by suspension sedimentation and low-density turbidity current in a lake. In the Namyang Basin FA I is distributed in the eastern and southern margin of the basin, FA II in the middle part of the basin as north-south tending band. and FA III in the western part. In the Tando Basin FA II is distributed in the middle part of eastern margin and in the northwestern margin, FA IV in the southwestern part, and FA V in the central part. Correlation of the facies associations shows that FA I and II in the Namyang Basin are distributed in the lower to middle part of stratigraphic sequence and FA III in the upper part of the sequence whereas FA II and IV in the Tando Basin are in the lower to middle part and FA V in the upper part of the sequence. These patterns of facies associations distribution suggest that the Namyang Basin was developed as an alluvial fan and alluvial/braided plain at first and then evolved into a floodplain whereas the Tando Basin was developed as a fan-delta and alluvial/braided plain at first and then evolved into a lake environment.

• Journal of Korea Water Resources Association
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• v.41 no.12
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• pp.1219-1230
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• 2008

Stream inflows induced by flood runoffs have a higher density than the ambient reservoir water because of a lower water temperature and elevated suspended sediment(SS) concentration. As the propagation of density currents that formed by density difference between inflow and ambient water affects reservoir water quality and ecosystem, an understanding of reservoir density current is essential for an optimization of filed monitoring, analysis and forecast of SS and nutrient transport, and their proper management and control. This study was aimed to quantify the characteristics of inflow density current including plunge depth($d_p$) and distance($X_p$), separation depth($d_s$), interflow thickness($h_i$), arrival time to dam($t_a$), reduction ratio(${\beta}$) of SS contained stream inflow for different flood magnitude in Daecheong Reservoir with a validated two-dimensional(2D) numerical model. 10 different flood scenarios corresponding to inflow densimetric Froude number($Fr_i$) range from 0.920 to 9.205 were set up based on the hydrograph obtained from June 13 to July 3, 2004. A fully developed stratification condition was assumed as an initial water temperature profile. Higher $Fr_i$(inertia-to-buoyancy ratio) resulted in a greater $d_p,\;X_p,\;d_s,\;h_i$, and faster propagation of interflow, while the effect of reservoir geometry on these characteristics was significant. The Hebbert equation that estimates $d_p$ assuming steady-state flow condition with triangular cross section substantially over-estimated the $d_p$ because it does not consider the spatial variation of reservoir geometry and water surface changes during flood events. The ${\beta}$ values between inflow and dam sites were decreased as $Fr_i$ increased, but reversed after $Fr_i$>9.0 because of turbulent mixing effect. The results provides a practical and effective prediction measures for reservoir operators to first capture the behavior of turbidity inflow.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.323-334
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• 2007

We analyzed the ocean environmental data from water sample and automatic measurement instruments with the Incheon-Jeju passenger ship for 18 times during 4 years from 2001 to 2004. The objectives of this study are to monitor the spatial and temporal variations of ocean environmental parameters in coastal waters of the Yellow Sea using water sample analysis, and to compare and analyze the reliability of automatic measurement sensors for chlorophyll and turbidity using in situ measurements. The chlorophyll concentration showed the ranges between 0.1 to $6.0mg/m^3$. High concentrations occurred in the Gyeonggi Bay through all the cruises. The maximum value of chlorophyll concentration was $16.5mg/m^3$ in this area during September 2004. The absorption coefficients of dissolve organic matter at 400 nm showed below $0.5m^{-1}$ except those in August 2001 During 2002-2003, it did not distinctly change the seasonal variations with the ranges 0.1 to $0.4m^{-1}$. In the case of suspended sediment (SS) concentration, most of the area showed below $20g/m^3$ through all seasons except the Gyeonggi Bay and around Mokpo area. In general SS concentration of autumn and winter season was higher than that of summer. The central area of the Yellow Sea appeared to have lower value $10g/m^3$. The YSI fluorometer for chlorophyll concentration had a very low reliability and turbidity sensor had a $R^2$ value of 0.77 through the 4 times measurements comparing with water sampling method. For the automatic measurement using instruments for chlorphlyll and suspended sediment concentration, McVan and Choses sensor was greater than YSI multisensor. The SeaWiFS SS distribution map was well spatially matched with in situ measurement, however, there was a little difference in quantitative concentration.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.664-669
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• 2011

Wet noodles with different percentages of amaranth powder were prepared and their cooking characteristics were evaluated. The cooking quality, mechanical textural properties, and a sensory evaluation was conducted with the prepared noodles. Cooked noodle properties, weight, and volume decreased as amaranth content of the wheat flour increased, whereas turbidity and water absorption of the soup increased, except for cooked noodles with 30% amaranth. The L-value of the raw and cooked noodles decreased significantly with increasing amaranth powder content. The a- and b-values increased with increasing amounts of added amaranth powder. The L-value of the raw and cooked noodles with amaranth was significantly lower than that of the control, and the a-value was lower than that of the control, whereas the b-value was higher than that of the control for both raw and cooked noodles. A texture profile analysis of the raw noodles showed significantly higher levels of hardness, cohesiveness, gumminess, chewiness, and springiness in the amaranth noodles compared to those in the control; the values for adhesiveness were not significantly different. The hardness, gumminess, springiness, and chewiness of the cooked noodles decreased in proportion to the quantity of added amaranth. The springiness, adhesiveness, and cohesiveness of cooked noodles with amaranth decreased slightly. Overall, the results of a sensory evaluation revealed that the cooked noodles with amaranth had higher values than those of the control, except for overall acceptability. Amaranth added at a concentration of up to 30% increased brown color and the peculiar amaranth odor. In a sensory evaluation, cooked noodles with 20% amaranth powder were preferred more than the other noodles for overall acceptability.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.676-682
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• 2016

In this study, rainwater-greywater hybrid system was installed and operated for 1 year in order to evaluate its water quantity, water quality, and economic efficiency in building no. 39. This system was expected to overcome each disadvantages of and maximize each advantages. Low-greywater that was washed up from shower room was treated by MBR (Membrane Bioreactor) and ozone oxidation. Rainwater that was collected from the rooftop was stored in a reservoir, and then transferred to the storage tank that was mixed with treated greywater. After 1 year operating in building no. 39, rainwater and greywater was used to supply $2,599m^3$ of toilet flushing water. In terms of water quality, rainwater was satisfied far the greywater reuse standards except for E.coli. Moreover, low greywater quality was acceptable except for E. coli, BOD, SS, and turbidity. In addition, economic analysis was obtained from benefit-cost ratio (B/C) with 1.11. It implies that the feasibility of the project was reasonable. Furthermore, various research and policy to improve the economic efficiency of water recycling facilities is required to expand the use of water recycling facilities.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.725-732
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• 2015

This study was conducted to compare the physicochemical and sensory characteristics of beef-bone broths prepared under atmospheric pressure (BBAP) and overpressure (BBOP). Beef-bone was boiled in water (bone/water=1:2, w/w) for 1, 2, 4, 6, and 12 h under atmospheric pressure and overpressure ($121^{\circ}C$, 1.25 atm). The BBOP broth samples were found to contain significantly higher amounts of solid, crude protein, crude ash, collagen, and chondroitin sulfate than the BBAP broth samples for a given boiling time (p<0.05). In addition, the Ca and Mg contents in the BBAP samples were higher than those in the BBOP samples, whereas the P, Na, and K contents were higher in BBOP than BBAP. The L value of BBAP was also significantly higher than that of BBOP (p<0.05). Further, as the boiling time increased, turbidity increased in the BBAP samples. In the quantitative descriptive analysis, the BBOP samples exhibited stronger brownness, transparency, meaty off-odor, meaty off-flavor, and sulfuric odor than the BBAP samples.

• Korean journal of food and cookery science
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• v.25 no.2
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• pp.180-188
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• 2009

This study investigated the quality of rice noodles containing different amounts of mesangi (Capsosiphon fulvescens) powder. The noodles were prepared with ratios of 1.9, 3.8, and 5.7% (w/w) of mesangi powder based on the flour weight. The noodles containing mesangi powder had lower moisture contents compared to the control, while amounts of ash were higher than in the control. For the cooking properties of the noodles, weight, volume, and turbidity were significantly higher in the mesangi rice noodles than the control (p<0.0001). The mesangi rice noodles had lower L- and a- values than the control, and these values decreased with increasing amounts of mesangi powder while the b- value increased. Texture profile analysis of the cooked noodles showed significantly higher levels of hardness (p<0.0001) and adhesiveness (p<0.05) in the mesangi rice noodles compared to the control, while cohesiveness (p<0.05), springiness (p<0.05), and gumminess (p<0.0001) values were lower than those of the control. However, the values for hardness, adhesiveness, cohesiveness, and springiness were not significantly different among the mesangi rice noodle groups. The pH of the rice noodles gradually decreased over 8 days of storage time. The 3.8% mesangi rice noodles had lower total and fungus plate counts than the other noodles during 15${\sim}$24 days of storage. However, the 3.8% masangi noodles showed the highest overall acceptability score(p<0.05).

• Journal of Ecology and Environment
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• v.40 no.1
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• pp.24-33
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• 2016

Background: Previous numerous studies on watershed scale demonstrated that the constructions of upper dams may influence the below dams due to modifications of flow regime and nutrient inputs. Little is known about how the dam constructions influence the downstream lakes or reservoirs in the regional scale. This study demonstrates how the construction of upper dam (i.e., Yongdam Dam) influences nutrient regime, trophic relations, and empirical models in Daechung Reservoir (DR). Yongdam Dam was constructed at the upstream region of DR in year 2000. Results: The analysis of hydrological variables showed that inflow and discharge in the DR were largely reduced after the year 2000. The construction of upper dam construction also resulted in increases of water temperature, pH and conductivity (as an indicator of ionic content) in the DR. Empirical models of TP-CHL and N:P ratio-CHL suggested that stronger responses of CHL to the phosphorus were evident after the upper dam construction, indicating that algal production at a unit phosphorus increased after the upper dam construction. Mann-Kendall tests on the relations of N:P ratios to TN showed weak or no relations ($t_{au}=-0.143$, z = -0.371, p = 0.7105) before the dam construction, while the relation of N:P ratios to TP showed strong in the periods of before- ($t_{au}=-0714$, z = -2.351, p = 0.0187) and after the construction ($t_{au}=-0.868$, z = -4.270, p = 0.0000). This outcome indicates that TP is key determinant on N:P ratios in the reservoir. Scatter Plots on Trophic State Index Deviations (TSIDs) of "TSI(SD) - TSI(CHL)" against "TSI(TP) - TSI(CHL)" showed that the dominance of clay turbidity or light limitation was evident before the upper dam construction [TSI(TP) - TSI(CHL) > 0 and TSI(SD) - TSI(CHL) > 0] and phosphorus limitation became stronger after the dam construction [(TSI(TP) - TSI(CHL) < 0 and TSI(SD) - TSI(CHL) > 0]. Conclusions: Overall, our analysis suggests that the upper dam construction modified the response of trophic components (phytoplankton) to the nutrients or nutrient ratios through the alteration of flow regime, resulting in modifications of ecological functions and trophic relations in the low trophic levels.