• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1009-1019
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• 2009

Soil nailing method is widely used in reinforcing slopes and excavating earth. The analysis of nail-reinforced slopes, in order to determine the economical length ratio and nail angle, complicated analytical need to be applied by means of computer programs. Therefor this suggested Soil stability Chart for nailed slopes which may be very useful for pre-design, rapidly design, and final check. Three slope types, three nail length and three nail angles are selected for the stability analysis by using limit equilibrium method of Bishop and French Method. From the above results, this study propose the slope reinforced design charts for dry season and rainy season. This proposed reinforced design charts can check dry season as well as rainy season, also these charts can provide reinforcing requirement, soil nail's economical length ratio and nail angle as well.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.129-136
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• 2008

The purpose of this study is to find an effective operating system for water supply of Andong Dam. The reliability of water supply was assessed by HEC-5 model based on operated water supply data of Andong Dam and data of Jin-dong water level gauge station in Nak- dong river. In addition, estimated additional amount of water supply was evaluated for each alternative by additional retention of Andong Dam in rainy season from June to September. As the result, additional amount of water supply of each alternative in non-rainy season (excluding rainy season) is increased as $1.35m^3/s{\sim}2.12m^3/s$, it shows that additional amount of water supply can be made by effective operating system for water supply in every dam as Andang Dam.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.193-200
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• 2007

The purpose of this study is investigate to water quality, pH, turbidity, salinity, nutrients, SS, DO, COD, ${NH_4}^+$-N, ${NO_2}^-+{NO_3}^-$-N, TN, TP, ${PO_4}^{3-}$-P in ditches and seawater of the Hwawon, southwestern coastal area of Korea. Two stations of the ditch, one station at outfall from reservoir of the coastal development and 15 stations of seawater were measured in August just after a 96.5 mm rainfall and in dry season of November 2006. The sampling time were divided into a rainy and dry season based on turbidity, SS, salinity and nutrients difference of distributions that was evidence as a inflow of pollutants from the developing coastal land area. The pH, turbidity, salinity and SS were high and showed different from between surface and bottom in near the developing of coastal land than the other stations after a strong rainfall over 90 mm while it were not varied in vertical and horizontal concentration profile in dry season. The other nutrients were showed the same concentrations gradient patterns. In opposition to expectations, the SS in dry season was higher than in the rainy season due to upwelling by the wind and strong current. It appears that the researched coastal seawater qualities were mainly effected by the inflow of freshwater from the ditches and drain from the reservoir of the developing land area during strong rainfall while the seawater qualities were mainly effected by the wind and strong current in dry season.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.819-832
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• 2012

HSPF model based on BASINS was applied for the Hwaseong Reservoir watershed (HRW) to evaluate the feasibility of water quality management. The watershed was divided into 45 sub-basins considering various watershed environment. Streamflow was calibrated based on the measured meteorological data, discharge data of treatment plants and observed streamflow data for 2010 year. Then the model was calibrated against the field measurements of water qualities, including BOD, T-N and T-P. In most cases, there were reasonable agreements between observed and predicted data. The validated model was used to analyze the characterization of pollutant load from study area. As a result, Non-point source pollutant loads during the rainy season was about 66~78% of total loads. In rainy-season, water quality parameters depended on precipitation and pollutant loads patterns, but their concentration were not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. As another result of evaluation for load duration curves, in order to improve water qualities to the satisfactory level, the watershed managements considering both time-variant and pollution sources must be required in the HRW. Overall, it was found that the model could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• Water Engineering Research
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• v.5 no.1
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• pp.17-36
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• 2004

This paper evaluated the water resources aspect of the operating results of the Daecheong Multipurpose Dam for the last 21 years. The elements that were evaluated included the amount of water supply from the dam. volume of outflow from the regulating dam, changes in the runoff volume at the dam site and downstream, and variations in the water supply capacity of the Daecheong Multipurpose Dam and the Geum River Barrage Dam situated in the estuary. The rainfall-runoff model was used to evaluate the changes in the runoff volume, and the water balance analysis system was used to evaluate the variations in the dams'water supply capacities. The volume of domestic and industrial water supply from the Daecheong Multipurpose Dam increased to 6.1 times for the last 21 years from 61${\times}$$10^6$$m^3$ in 1981 to 375${\times}$$10^6$$m^3$in 2001. The rate of outflow to inflow of the Daecheong Dam was analyzed 1.30 times in dry season, 1.12 times in semi-dry season, and 0.90 times in rainy season. The volume of inflow to the Geum River Barrage Dam down- stream after the dam's construction increased to 1.25 times in dry season and 1.02 times in semi-dry season and decreased to 0.94 times in rainy season. The water supply capacity of the estuary barrage dam almost did not change in cases with or without the Daecheong Multipurpose Dam, but storages were largely affected by the outflows of the Daecheong Multipurpose Dam.

• Journal of Korean Society on Water Environment
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• v.29 no.6
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• pp.739-745
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• 2013

This paper investigated the runoff characteristics of different properties of suspended solids in streams according to the watershed characteristics and dry/rainy season. Suspended solids were divided into VSS and NVSS depending on volatilization. The main results of this study were as follows. TSS were more correlated with NVSS than VSS. Suspended solids were positively related with the proportion of urban > paddy > upland, negatively related with forest cover. VSS were positively correlated with POP and POC. VSS, measured in dry season, would partly result from autochthonous production and could be an indirect indicator of organic suspended solids.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.708-718
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• 2010

The objective of the current study was to determine seasonal changes in glucose, cholesterol, non-esterified fatty acids (NEFA), serum inorganic phosphorous (SIP), calcium, magnesium and iron concentrations in Nguni and crossbred cattle on the sweet and sour rangelands of the Eastern Cape Province of South Africa. Body weights, body condition scores (BCS) and serum concentrations of energy-related metabolites and mineral profiles were determined in late cool-dry, hot-dry, hot-wet, post-rainy and early cool-dry seasons in 100 cattle raised on communal rangelands from August 2007 to May 2008. Nguni cattle had lower (p<0.05) and higher (p<0.05) serum concentrations of glucose in the hot-wet and post-rainy seasons, respectively, compared to crossbreds in the same seasons. Serum cholesterol and NEFA concentrations in Nguni were lower (p<0.05) than in the crossbreds. Nguni and crossbred cattle had higher (p<0.05) serum NEFA concentrations on the sweet rangeland during the late cool-dry season than on sour rangeland. Nguni cattle had higher (p<0.05) SIP concentration in the hot-wet season than the crossbreds. Generally, both breeds had lowest SIP concentration during the hot-wet season on the sour rangeland. The lowest magnesium and highest iron concentrations were observed in the hot-wet and post-rainy seasons, respectively, compared to other seasons. Cattle on the sour rangeland had lower (p<0.05) iron concentrations than those on the sweet rangeland. It was concluded that Nguni cattle had lower cholesterol and NEFA, and higher SIP concentrations in the hot-wet season than crossbreds and energy deficits mostly occurred during the late cool-dry season on the sweet rangeland.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.165-171
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• 2002

A study was conducted to investigate the seasonal changes in water quality of watershed in the Agricultural Environment Promotion Zone. Samples collected were 12 GW (ground water), 2 IW (irrigation water), 2 SW (stream water) in An-Dong City, 4 GW, 6 IW, 11 SW in Young-Yang Gun, and sampling was conducted separately during dry and rainy season. In the ground water, EC and ionic species, except pH, were higher than those in stream water, and especially $NO_3-N$ concentration exceeded the limitation of drinking water. Concentration of ions decreased as the sampling depth was far from the soil surface. During a rainy season, the concentrations of $NO_3-N$ and K in the stream water were slightly higher than those during season. COD was lower during dry season in Yong-Yang, while the trend was contrasted to An-Dong. These results suggest that ground water was polluted by fertilization and compost while streamwater was polluted by loss of soil and organic during the rainy season. Principal chemical components related with changing water quality were EC, $NO_3^-$, Ca, Mg, Na, $Cl^-$, $Cl^-$, $SO_4^-$ in ground water, whereas $NH_4-N$, K, Mg, $Cl^-$, $SO_4^-$ in stream water.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.19-31
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• 2011

This study had been carried out to investigate spatial and temporal variations of the concentrations of trace metals for contaminated surface water in creek affected by leachate from the tailings impoundment of the Yeonhwa II mine for about 2 years. It was also to ascertain the metal removal efficiency for potentially deleterious metals by the artificial and natural attenuation processes such as retention ponds and hydrologic mixing of uncontaminated tributaries. The concentrations of As, Pb, Cd, and Cu for leachate in the rainy season were not detected. On the other hand, the concentrations of Zn, Fe, Mn, Al, and $SO_4^{2-}$ in the rainy season for leachate were 2-66 times higher than those in the dry season, due to the oxidation of the sulfide minerals and the dissolution of the secondary minerals. The concentrations of Zn and Cd for leachate and surface water of the upper creek in the rainy season exceeded the criteria of River Water Quality and Drinking Water Quality but in the dry season, those of analyzed all the metals (As, Pb, Cd, Cu, Zn, Cd, Fe, Mn, and Al) for surface water sampled at the study area were below the criteria of River Water Quality and Drinking Water Quality. In regard of the attenuation efficiency for the concentrations of metals, Fe, Mn, Al, Zn, Cd, As, and Cu were removed highly at retention ponds, while the removal efficiency for major cations and sulfate ($SO_4^{2-}$) were related to mixing of the uncontaminated tributaries. Therefore, the major attenuation processes of the metal and sulfate contents in creek affected by leachate from a tailing dump were precipitation (accompanied by metal co-precipitation and sorption), water dilution, and neutralization.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.134-145
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• 2023

Background: The flowering and fruiting periods play an important role in biological processes. The deciduous dipterocarp forest is an important forest type in Thailand, however the phenological studies are still limited, particularly in different plant life forms. Thus, the present study focused on the flowering and fruiting phenology of herbs, climbers, shrubs, and trees in the deciduous dipterocarp forest at Lampang province of Northern Thailand. Field visits were made to record plant life forms and observe reproductive phenological events at monthly intervals from November 2018 to October 2019 and September to December 2020. Results: The phenological observations were based on 126 species of 45 families and 102 genera. Flowering and fruiting periods showed similar patterns in herbaceous plants, climbers, and shrubs. Most of these species produced flowers and fruits from the end of the rainy season (October) to the winter season (November-January). Whereas most of flowering and fruiting trees were found from the summer season (March-April) to the beginning of the rainy season (May-June). Most of the dry-fruited species occurred during the dry period (winter and summer seasons), while the majority of fleshy-fruited species dominated in the wet period (rainy season). The statistical analysis supported the phenological patterns of flowering and fruiting in the present study. There were significant negative correlations between the number of flowering and fruiting species and temperature. The number of flowering and fruiting species is significantly impacted by the interaction between seasons and plant life forms. Conclusions: Plant life form seems to be the important factor that affects the different phenological patterns in the studied plants. The abiotic and biotic factors play major roles in reproductive phenology. However, long-term study and in-depth phenological observations are necessary for better understanding.