• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.65-72
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• 2002

Rainfall and runoff data from a forested watershed and irrigated rice paddies at the Bal-an experimental watershed were monitored and analyzed to investigate the variations of runoff characteristics with different land use. The comparisons were conducted fourteen storm events ranging 21.8∼190.2 mm of rainfall. Field data showed that direct runoff from paddies and forested watershed are not significantly different in volume. The peak discharge from forest watershed was less than that from paddies far lighter storms, but became greater fur heavier storms. The peak runoff from the forest watershed was 39 percent greater than from the paddies. The results demonstrate that paddies play an important role to reduce peak discharge from heavy storms as compared to forest.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.283-291
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• 1993

These studies were carried out to investigate water yield from small forested watersheds at Choosan Stream-Gauging Stations in Chollanam-do province from May 11, 1991 to December 31, 1992. The purpose of these studies was to obtain useful informations as distribution of precipitation, canopy interception, stemflow, throughfall and run-off from the small forested watersheds. The precipitation at Choosan from May to December, 1991 was 1,306.6mm and at Choosan from January to December, 1992 was 1,143.4mm. The rate of canopy interception in Pinus taeda stand is 24.3% and 27% in Pinus densiflora stand. The run-off rate from the watershed was 48.87% at Bukmoongol small forested watershed and 41.19% at Baramgol small forested watershed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.32-40
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• 2001

Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around Mt. Paekun area were monitored seasonally and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality were observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases in physicochemical indices such as the amount of dissolved oxygen, percentage of dissolved oxygen, total amount of cation, total amount of anion and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design should be incorporated to large scale fish farm development plan in forested watershed area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.54-63
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• 1999

Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around (Mt.) Paekun area were monitored by seasons and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality was also observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases of physicochemical indexes such as the amount of dissolved oxygen, percentage of dissolved oxygen and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design be incorporated to large scale fish farm development plan in forested watershed area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.3
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• pp.43-52
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• 2005

Evaluations of the fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research influent, effluent water in the fish farm and stream water qualities around Mt. Baegun area were monitored seasonally for six years and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Also, effluent water from the fish farm increase of EC higher than influent and stream water. As a result of regression analyses, pH, EC, DO, water temperature, total amount of cation and anion in influent and effluent water of fish farm show high significance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.4
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• pp.46-55
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• 2001

Analysis of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around Mt. Baegun area were monitored seasonally for three years. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. As a result of regression analyses, the linear equation of pH of influent and effluent water of fish farm was, pH of effluent water of fish farm = $0.6234{\times}pH$ of influent water of fish farm + 2.6263. Also, the linear equation of electrical conductivity of influent and effluent water of fish farm was electrical conductivity of effluent water of fish farm = $1.7275{\times}$electrical conductivity of influent water of fish farm - 14.007. Negative effects on stream water quality were observed by indications of increase in electrical conductivity and water temperature of effluent water from the fish farm. Decreases in physicochemical indices such as the amount of dissolved oxygen, total amount of cation and total amount of anion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as environmentally-friendly fish farm design should be incorporated to large scale fish farm development plan in forested watershed area.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.383-391
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• 2014

Long-term changes in the hydrological characteristics of a small forest watershed were examined using a master baseflow recession curve and the measured rainfall-runoff data from the experimental forest watershed in the measured years 2003-2011. The results of the study showed that the recession coefficient of direct runoff was lower than that of baseflow. In small forested watershed, the direct flow was lower than that of large scale watershed, flow due to its shorter period of occurrence. And baseflow was similar to large scale watershed's. A regression equation $y=0.7528e^{-0.022x}$($R^2=0.8938$, range 0.3~0.8 mm) was obtained using the master baseflow recession curve for the study period and the recession coefficient was calculated as K = 0.978. Changes between master baseflow recession curve and runoff showed great association and relevance such as increasing runoff was associated with the gentle slope of master baseflow recession curve and decreasing runoff was associated with the slope of master baseflow recession curve contrary. In the later years of the study period, the slope of the master baseflow recession curve appreciably became more gentle due to increases in baseflow. This suggests that the forested experimental watershed exhibit improved structural functioning of normal flood control and reduced occurrence of water shortage problems.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.564-575
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• 2000

This study was carried out to reveal characteristics of long-term runoff by using HYCYMODEL in a small forested watershed. From May to September in 1998 and in 1999, the fitness of HYCYMODEL and runoff characteristics were estimated by HYCYMODEL using rainfall and discharge at the experimental watershed. The function of stage and discharge in the experimental watershed was determined as following equation $Q=11.148H^{2.5867}$($R^2=0.9956$). From May to September in 1998 and in 1999, the runoff rates were 57.7% in 1998 and 87.1% in 1999 at the experimental watershed. The discharge was assumed to be increased because of rainfall intensity difference and thinning. By applicability test, the HYCYMODEL showed good estimation of runoff by optimized fifteen parameters. Comparing runoff characteristics before and after thinning by calculating through HYCYMODEL, direct runoff and base runoff increased 4%, 7%, respectively as evapotranspiration decreased 11%. Parameters $D_{50}$ and $K_h$, which were related to the direct run, and a parameter $K_u$, which was related to the baseflow, were assumed to indicate that forest was changed by the effect of thinning and weathering process of bed rock.

• Environmental Engineering Research
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• v.14 no.1
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• pp.13-18
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• 2009

In this study, specific pollutant releases during the Asian monsoon season were estimated and the information was applied to the non-point pollutant sources management from two forested watersheds of the Soyang Lake. The two watersheds are part of the 2,703 km2 Soyang Lake watershed in the northern region of the Han River. The outlets of the two watersheds were respectively analyzed for continuous water quality concentration and for discharge during various single rainfall events. Statistical power function methods are utilized to compare stream discharge and pollutant flux release during the study period. Based on the monitoring data during the study period, the specific load flux method using simulated discharge was conducted and validated in the two watersheds. The model predictions corresponded well with the measured and calculated pollutant releases. The modeling approach taken in this study was found to be applicable for the two forested watersheds.

• The Korean Journal of Ecology
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• v.25 no.2
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• pp.119-125
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• 2002

In order to elucidate the budget and cycling of Nitrogen and Sulfur, esential elements and principal constituents of acid rain, their input through precipitation, and their output by streamflow were quantified in coniferous and deciduous forested watersheds, using combination of nutrient concentration and hydrological analysis, in Kwangnung Experimental Forest from July 1991 to Decmeber 1993. Amount of annual mean precipitation was 12.916 ton·ha/sup -1/·yr/sup -1/, annual mean runoff 5,094 ton·ha/sup -1/·yr/sup -1/(39%), 7,647 ton·ha/sup -1/·yr/sup -1/(59%) in coniferous and deciduous forest watersheds, respectively. Amounts of annual input of N(NO₃/sup -/+NH₄/sup +/) and SO/sup 2-/₄ through preciptation were 12.5, 81.7 kg·ha/sup -1/·yr/sup -1/, respectively. Annual output via runoff of N(NO₃/sup -/+NH₄/sup +/) and SO/sup 2-/₄were 0.06, 39.23 ton·ha/sup -1/·yr/sup -1/ in the coniferous forest watershed ecosystem, and 0.15, 55.46 ton·ha/sup -1/·yr/sup -1/ in the deciduous one, respectively. On the basis of annual nutrient input and output, the annual budget of N(NO₃/sup -/+NH₄/sup +/) and SO/sup 2-/₄were +12.46, +42.49 ton·ha/sup -1/·yr/sup -1/ in the coniferous forest watershed, and +11.35, +26.26 ton·ha/sup -1/·yr/sup -1/ in the deciduous one. Thus N(NO₃/sup -/+NH₄/sup +/) and SO/sup 2-/₄were accumulated in both forested watershed ecosystems.