• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.170-176
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• 1998

Nitrogen and phosphorus loads from an agricultural watershed of the Yulmun-chon tributary in the Buk-Han River Basin were quantified based on total amounts of water stream flow. The water quality and soil loss were estimated. Levels of the stream were recorded automatically using the water level meter. The flow velocities, along with the cross-sectional areas of the riverbed, were measured to estimate total amounts of water flow at three monitoring sites in this tributary. Water samples were collected at nine sites with two weeks interval from May to August and analyzed for the water quality parameters. Amounts of soil loss were estimated by the USLE. The size of the Yulmunchon watershed was 3,210 ha, of which paddy and upland soil areas were composed about 41%. The total amounts of soil loss from the watershed areas were estimated to be $13,273Mg\;year^{-1}$, showing 53%, 46% and 0.7% of the soil loss ratio from upland, forest, and paddy areas, respectively. Electrical conductivities and Nitrogen concentrations of the stream water were higher in the lower watershed area than in the upper area. Increments of N were higher for $NO_3-N$ than $NH_4-N$. Nitrate nitrogen was the major N form to pollute the water due to the agricultural activity. Total runoff was about 72% of the total precipitation in the watershed. The maximum loads of T-N and T-P due to the runoff were estimated to be 1,500 and $5kg\;day^{-1}$, respectively. Concentrations of $NO_3-N$ and $NH_4-N$ in the runoff were 13.5 and 1.8 times higher than those in precipitation. The N loads were mainly from soil loss, application of fertilizer, and livestock wastes, which were 52% of total N load. Results demonstrated that reduction of fertilizer use and the soil loss would be essential for water quality protection of the agricultural watershed.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.201-213
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• 2007

In this study, the Batter Assessment Science Integrating point and Nonpoint Sources (BASINS 3.0)/window interface to Hydrological Simulation Program-FPRTRAN (WinHSPF) was applied for assessment of Soyang Dam watershed. WinHSPF calibration was performed using monitoring data from 2000 to 2004 to simulate stream flow. Water quality (water temperature, DO, BOD, nitrate, total organic nitrogen, total nitrogen, total organic phosphorus and total phosphorus) was calibrated. Calibration results for dry-days and wet-days simulation were reasonably matched with observed data in stream flow, temperature, DO, BOD and nutrient simulation. Some deviation in the model results were caused by the lack of measured watershed data, hydraulic structure data and meteorological data. It was found that most of pollutant loading was contributed by nonpoint source pollution showing about $98.6%{\sim}99.0%$. The WinHSPF BMPRAC was applied to evaluate the water quality improvement. These scenarios included constructed wetland for controlling nonpoint source poilution and wet detention pond. The results illustrated that reasonably reduced pollutant loadin. Overall, BASINS/WinHSPF was found to be applicable and can be a powerful tool in pollutant loading and BMP efficiency estimation from the watershed.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.100-109
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• 2006

This study evaluated the effects of water velocity, substrates, and phosphorus concentrations on the growth of filamentous periphytic algae (FPA) in the two types of artificial channel systems using treated wastewater. Controlled parameters included 5 ${\sim}$ 15 cm $s^{-1}$ for the water velocity; 10 and 20 mm wire meshes, natural fiber net, gravel and tile for the substrates: and 0.05 ${\sim}$ 1.0 mgP $L^{-1}$ for the P concentration. Algal growth rate of FPA was compared using both chi. a and dry weight change with time. Under the controlled water velocity range, the growth of FPA increased with the velocity, but the maximum growth rate was shown in the velocity of 10 cm $s^{-1}$. The substrate that showed the maximum growth of FPA differed between the artificial channel and indoor channel, due to the influence of suspended matters which caused the clogging of the meshed substrates. Under the controled range of P concentration, the growth rates of all three FPA species (Spirogyra turfosa, Oedogonium fovelatum, Rhizoclonium riparium) increased with the P increase, but they showed the differential growth rates among different P concentrations. The results of this study suggest that under the circumstance having an large amount of nutrients FPA develop the biomass rapidly and that even a little increase over the threshold velocity causes the detachment of filamentous periphytic algae. Thus, FPA dynamics in eutrophic streams, such as those receiving treated wastewater, seem to be sensitive to the water velocity. On the other hand, detached algal filaments could deteriorate water quality and ecosystem function in receiving streams or down-stream, and thus they need to be recognized as an important factor in water quality management in eutrophic streams.

• Journal of Aquaculture
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• v.17 no.2
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• pp.144-150
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• 2004

This experiment was conducted to evaluate the parameters such as nutrient requirements, POY, AnV, Totox, VBN, total plate count, dietary fatty acids and amino acids composition, that are not included in the registered standard composition items required by the Ministry of Agriculture and Forestry, of a moist pellet (MP), three domestic extruded pellets (DEP-1, DEP-2, DEP-3), and two foreign extruded pellets (FEP-1, FEP-2) that are utilized by domestic flounder farms at present. The crude protein was added in excess of the dietary protein requirement in 6 kinds of feeds. When considering the proper PH ratio, it is obvious that protein was added in excess, especially in MP and FEP-2. Crude fat was also added in excess, especially in FEP-1. MP contained a higher dietary phosphorus content than formulated feeds, surpassing the dietary phosphorus requirement and greatly increasing the possibility for causing water pollution. The oxidation of fatty acid and decomposition of protein in MP were higher than in formulated feeds, and may also cause problems on fish farms. Also, it is difficult to store and manage MP, Among the fatty acids, EPA and DHA contents in MP were higher than those in formulated feeds. It is necessary to conduct further studies of EPA and DHA contents in formulated feeds. Lysine content in MP and FEP-2 could meet the dietary lysine requirement of flounder, however, the possibility of insufficient lysine content in the other formulated feeds was high and we considered that extra supplementation was necessary. Therefore, it is necessary to set up quality control standards according to fish species and sizes while considering the specific character of aquatic formulated feeds to restore the confidence of feed companies and aquaculturists to these feeds. This may be an opportunity to make an earlier change from MP to formulated feeds.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.90-100
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• 2012

This study centering on 10 village - Bangjuks analyzed multifunctionality value of village Bangjuks which have been main water treatment system in Korean traditional villages. On the basis of understanding the structure and character of components such as the well, common spring, village waterway and others which making water-flow and consisting of aquatic system in Korean traditional village Bangjuk, the conclusion as the instrumental device of social and ecological role and ecological watershed management, securing the ecosystem soundness of the damaged or deteriated aquatic ecosystem due to the industrialization and urbanization is as below; 1. The traditional village Bangjuk was environmentally friendly hydraulic system which gathers waterways of village into a point including sewage water, retains and flows out to village through agricultural waterway. Through this Bangjuk, they have managed sewage and rainfall runoff flowed out village efficiently. It is not only a detention system of water but a kind of eco-friendly system that flow out water into the rivers after reusing and filtering it. 2. Around five traditional villages and five villages after modernization, this study classified the types of village Bangjuk as three types considering geographic location, size, etc; marsh type of low swamp, high water -low rice field type of natural flow stucture, low water - high rice field type requiring artificial irrigation facility. All the five traditional villages were turned out to be marsh type of low swamp. Geoji, Sanjeri, Ma-am, Yangchon of the agricultural villages were high water-low rice filed type, and Sangchoenri village was classified low water-high rice field type. 3. This study checked up the function of water purification of village Bangjuk. In Wonteo and Geji villages affected by discharge of village sewer and domestic sewage, the efficiency of ammonia nitrogen($NH_3-N$) and total phosphorus(T-P) was 56~95%, which was high. In Sangcheonri and Sanjeri villages strongly affected by stall and farmland, the efficiency of suspended solids(SS) was 70~85%, and that of total nitrogen(T-N) and total phosphorus(T-P) was 5.3~65%. 4. A water purification system can be found out in the system of village Bangjuk that filter out village sewage and rainfall runoff flowed through the settle and filter of pollution source and denitrification of plants. Through this system of village Bangjuk, it must be used as the basic facilities for the ecological watershed management. The sewage management system of village Bangjuk as a eco-filter must be used and studied as an eco-friendly facility for the ecological watershed management around the subwatershed and catchment.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.457-465
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• 2008

The purpose of the study was to evaluate spatial and temporal dynamics of nutrients (TN, TP), organic pollution (BOD, COD), and ionic dynamics (electrical conductivity, EC) in the North Han-River, South Han-River, and merged downriver using the dataset of $1998{\sim}2007$, obtained from the MEK (Ministry of Environment, Korea). Accord. ing to interannual nutrient analysis, TN varied slightly in the North Han-River and South Han-River, but decreased in the merged downriver along with BOD. Longitudinal analysis in the water quality showed that BOD, COD, and nutrients had linear decreasing trend along the main axis of headwater-to-downriver. Concentrations of TP and TN in the North Han-River averaged $26.97{\mu}g\;L^{-1}$, $1.696mg\;L^{-1}$, respectively, which were minimum in the three watersheds, followed by South Han-River and then the merged downriver in order. Ratios of TN:TP in the watersheds were >40 in all the sites, indicating that nitrogen may be enough for periphyton or phytoplankton growth and phosphorus may be limited partially. After the North Han-River water is merged with South Han-River, the concentrations of BOD, COD, TN, and TP were similar to the values of $S6{\sim}S7$, respectively or a little bit higher, but increased abruptly in Site M4 (Fig. 3). Thus, mean values of all the water quality parameters in the reach of $M4{\sim}M7$ sites were greater than any other sites. Seasonal data analysis indicated that BOD and EC in the downstream ($S3{\sim}S7$) was greater in the premonsoon than two seasons of the monsoon and postmonsoon, and no significant differences in BOD between the three seasons were found in the upstream ($S1{\sim}S2$). Empirical models of COD in the merged downriver was predicted ($R^2=0.87$, p>0.01, slope = 0.84, intercept = -1.28) well by EC. These results suggest that EC to be measured easily in the field may be used for estimations of nutrients and organic matter pollutions in the merged downriver and these linear models are cost-effective for the monitoring of the parameters.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.802-810
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• 2000

A total of 120 finishing crossbred pigs ($Landrace{\times}Large$ $White{\times}Duroc$) with equal numbers of barrows and gilts weighing 58.5 kg body weight were used in a feeding trial, and 6 pigs (three of each sex) were used in a metabolic trial to investigate the effect of phase feeding. Finishing period was divided into two phases and 4 different diets were fed for those periods. Growth performance was not significantly different among treatments within the same sex. This result showed that 16% crude protein for early finishing period and 14% crude protein diet for late finishing period should be optimum. During the early finishing period, only feed intake was significantly different between sexes (p<0.01), but in late finishing period daily weight gain (p<0.001) and feed intake (p<0.01) of barrows were significantly higher than those of gilts. During the early finishing period, digestibilities of dry matter, protein and phosphorus were significantly higher in gilts than in barrows (p<0.05). However, there was no treatment effect within same sex during the early and late finishing period. During early finishing period, excretion of N of pigs fed 16% CP diet in early and 14% CP diet in late-finishing period was less than that of pigs fed 17% CP diet in early and 15% CP diet in late-finishing period (p<0.05), but the difference was not significant. During the late finishing period, N excretion with two phase feeding was reduced by 8.5% compared with single feeding. In gilts, total cost reduction by two phase feeding compared to single feeding was 9.1%, but in barrows it was just 3.19%. Relative margin increased with two phase feeding by 2.5% in gUts and 0.2% in barrows. There was a tendency that backfat thickness at 10th rib of gilts was thinner than that of barrows (p>0.05). Within the same sexes, there was no treatment effect on back fat thickness (p>0.05). Carcass grade was improved by two phase feeding compared to single feeding. Carcass grade of gilts was significantly better than that of barrows (p<0.001). From this results, it is concluded that finishing pigs could be fed two-phase diets to improve profit and reduce pollution.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1588-1596
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• 2006

An experiment was conducted to study the effect of different dietary protein levels on the performance, nutrient balances, blood biochemical parameters and thyroid hormones of crossbred calves. Thirty crossbred (Bos taurus${\times}$Bos indicus) calves aged 3-5 months were divided into 3 equal groups of 10 each and fed graded levels of crude protein, namely 100 (NP), 75 (LP) and 125 (HP) percent of the Kearl recommendations for 105 d. The calves had access to ad libitum oat hay as the basal roughage. A metabolism trial of 6 d duration was conducted at 90 d of the study. Blood collection and its analysis for various hematological and biochemical parameters as well as thyroid hormones was done both during the pre- and post-experimental periods. The fortnightly body weight changes and the net gain did not differ significantly due to dietary variation. The average daily gain was $367{\pm}21.6$, $347{\pm}22.9$ and $337{\pm}26.4g$ in calves fed NP, LP and HP diets, respectively. Averaged across the feeding trial, oat hay intake was higher (p<0.05) in NP animals than HP or LP fed groups. The dry matter (DM) intake showed no significant difference between the 3 groups but the DM digestibility was higher (p<0.05) in the HP fed animals. The digestibility of crude protein, organic matter, crude fiber and nitrogen-free extract was significantly higher (p<0.05) on HP diets compared to LP or NP diets. The calves on all 3 diets were in positive nitrogen (N) balance, however the N retention was higher (p<0.05) in HP than in LP fed calves. The intake and retention of calcium and phosphorus were similar between the treatments. The blood biochemical profile revealed no significant influence of the dietary treatments on hemoglobin, packed cell volume as well as serum levels of glucose, total protein, albumin, globulin, Ca, P, and alkaline phosphatase. Serum levels of the circulating thyroid hormones ($T_3$ and $T_4$) tended to be lower (p>0.05) on feeding of the LP diet besides showing an increasing trend with the advancement of age. Considering the similar performance and metabolic profile, it could be concluded that crossbred calves can be satisfactorily reared on 25% lower protein level as recommended by Kearl for developing countries, which would not only economize the cost of production but also help to reduce environmental pollution attributable to livestock production.

• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.445-462
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• 1997

This study was conducted to analyze the spatial and temporal characteristics of stream water quality and to charify the management of watershed environment from the standpoint of hydrological geography. To achieve the purpose of the study, the Wangsook River was chosen. As the result of this study, the specific conclusions were drawn. 1. In general, WT(water temperature) of the downstream is higher than that of the upstream. The value of winter WT measured in densely populated area is higher than that measured under the natural conditions. The seasonal variation of WT at upstream sites is greater than that of downstream. 2. Rhe water quality of main channel is dependent on that of tributaries. Especially, the values of pH, EC, TDS in main channel depend upon those of tributaries. Among the tributaries of the Wangsook river, the Jingun-chon and Yongam-chon have mostly influence on the water quality of the main channel. 3. Generally, the values of COD measured in the Wangsook River are over the 5th Grade considering from a point of water quality standards of inland lake. However, BOD, phosphorus and nitrogen concentrations have to be measured to clear the water quality conditions of the river. 4. The regional people who live in the catchment of Wangsook river have different perception about the water pollution of the river. The regional people lacks in the understanding of the Wangsook river cause a bad influence upon the hydrological management of watershed environment.

• Korean Journal of Environmental Biology
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• v.31 no.2
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• pp.96-104
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• 2013

The objectives of this study were to analyze chemical the water quality related to the fish community and to evaluate the ecosystem health based on the faunal composition and guild structure in 2007 in Baekma River. Mean concentrations of biological oxygen demand (BOD) and chemical oxygen demand (COD) were 2.8 and $4.0mg\;L^{-1}$, respectively and total nitrogen (TN) and total phosphorus (TP) were $5.0mg\;L^{-1}$ and $158{\mu}g\;L^{-1}$, which is indicating that the river is in an eutrophic state. Especially, organic pollution and eutrophication occurred in the downstream reach of Baekma River. A total of 19 fish species were collected during the study and the most dominant species was Opsariichthys uncirostris amurensis accounted 48% of the total abundances. The proportion of sensitive species was low (2.3%), compared with that of tolerant species (71.8%). These results suggest that tolerant species and the biotic quality of the fish community was severely degraded. According to the multi-metric model, the Index of Biological Integrity (IBI), the mean model value of the fish community in Baekma River was estimated as 14.8 indicating a "poor" condition. The minimum values of the IBI were observed in the downstreams, and this was mainly attributed to chemical pollutions of nutrients (N, P) and organic matters.