• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.807-814
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• 2006

Sapkyo Lake Watershed occupies about 19.3% of total area of Chungnam Province, and it is necessary to make a plan of counter-measure for the maintenance of public waterbody sound as well as to ensure water resources due to urbanization and industrialization in this area so densely populated and excessively developed. Conventionally water quality management has been enforced by concentration-based system which is not considered the carrying capacity of receptors, hence there are no proper measures for the prevention of an excessive pollutant load over a waterbody. So even though emission sources abide by the conventional permission regulation, then the quantity of wastewater is increased continuously and encountered water shortage to use finally. Therefore this research focused on the review of introduction of total water quality management system in Sapkyo Lake watershed to maintain public waterbody sound and to ensure water resources. By doing this research in introduction of the system in advance, it can contribute to establish the methodology on systematic water quality management. Also the application of this system in Sapkyo Lake watershed can promote the sustainable development of the area by harmonizing the environment and regional economy ultimately.

• 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.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.151-152
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• 2008

The planning and management of the watershed environment require huge amount of information regarding almost all aspects of natural and manmade features of the area. Until lately this study could be achieved through days of exhaustive surveys map generation and tedious calculations. Remote sensing and GIS provides huge temporal database for an area and GIS provides the powerful tool for spatial and non-spatial analysis of remotely sensed data. The paper highlights the assessment of land potentiality using weighed overlay analysis with drainage density, soil, slope and lineament, LULC map was used to identify the utilization area of the watershed. The arithmetic overlay analysis was performed with potential and utilization layer to assess the availability of land for the future development.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.650-658
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• 2007

The Universal Soil Loss Equation (USLE) has been used in over 100 countries to estimate potential long-term soil erosion from the field. However, the USLE estimated soil erosion cannot be used to estimate the sediment delivered to the stream networks. For an effective erosion control, it is necessary to compute sediment delivery ratio (SDR) for watershed and sediment yield at watershed outlet. Thus, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to compute the sediment yield at any point in watershed. In this study, the SATEEC was applied to the Sudong watershed, Chuncheon Gangwon to compare the sediment yield using area-based sediment delivery ratio (SDRA) and slope-based sediment delivery ratio (SDRS) at watershed outlet. The sediment yield using the SDRA by Vanoni, SYA and the sediment yield using the SDRS by Willams and Berndt, SYS were compared for the same sized watersheds. The 19 subwatersheds was 2.19 ha in size, the soil loss and sediment yield were estimated for each subwatershed. Average slope of main stream was about 0.86~3.17%. Soil loss and sediment yield using SDRA and SDRS were distinguished depending on topography, especially in steep and flat areas. The SDRA for all subwatersheds was 0.762, however the SDRS were estimated in the range of 0.553~0.999. The difference between SYA and SYS was -79.74~27.45%. Thus site specific slope-based SDR is more effective in sediment yield estimation than area-based SDR. However it is recommended that watershed characteristic need to be considered in estimating yield behaviors.

• Journal of Korean Society on Water Environment
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• v.37 no.3
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• pp.204-216
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• 2021

It is important to understand the factors influencing the temporal and spatial variability of water quality in order to establish an effective customized management strategy for contaminated aquatic ecosystems. In this study, the spatial diversity of the 5-year (2015 - 2019) average total phosphorus (TP) concentration observed in 40 Total Maximum Daily Loads unit-basins in the Nakdong River watershed was analyzed using 50 predictive variables of watershed characteristics, climate characteristics, land use characteristics, and soil characteristics. Cross-correlation analysis, a two-stage exhaustive search approach, and Bayesian inference were applied to identify predictors that best matched the time-averaged TP. The predictors that were finally identified included watershed altitude, precipitation in fall, precipitation in winter, residential area, public facilities area, paddy field, soil available phosphate, soil magnesium, soil available silicic acid, and soil potassium. Among them, it was found that the most influential factors for the spatial difference of TP were watershed altitude in watershed characteristics, public facilities area in land use characteristics, and soil available silicic acid in soil characteristics. This means that artificial factors have a great influence on the spatial variability of TP. It is expected that the proposed statistical modeling approach can be applied to the identification of major factors affecting the spatial variability of the temporal average state of various water quality parameters.

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.397-406
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• 2015

The different compliance concentration of effluent limit is applied to effluent discharged from public sewage treatment works(PSTWs) in each watershed on the basis of water quality thereof in accordance with the enforced Watershed Sewer System Maintenance Plan in 2013. It is necessary to set the compliance concentration of effluent limit for PSTWs in watershed sewer system, in order to achieve water quality criteria for regional watersheds or target water quality under TMDL program. Watershed Environmental Agencies establish the Watershed Sewer System Maintenance Plan and set the compliance concentration of effluent limit for PSTWs under the plan. The agencies have a plan to apply strengthened effluent BOD concentration limits for PSTWs in I to IV area grade, respectively. Effluent BOD concentration limits will be strengthened from 5~10 mg/L to 3 mg/L in II~III area grade, from 10 mg/L to 5 mg/L in IV area grade. Uniform application of effluent BOD concentration limits to PSTWs in the watershed sewer system need to be complemented considering type of sewage treatment technology employed and watershed characteristics. Therefore, this study presents assessment methodology which analyze for the compliance concentration of effluent limit to affect water quality of discharge watershed using simulation model for the Jinwee-stream watershed.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1171-1176
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• 2005

This study was conducted to identify the runoff characteristics of non-point source according to rainfall in Dalseo and Daemyung watershed. Land-uses of the Dalseo and Daemyung watershed were surveyed to urban $72.1\%$ and mountainous $6.7\%$, and urban $49.3\%$ and mountainous $20.5\%$, respectively Mean runoff coefficients in each area were estimated to Dalseo watershed 0.49 and Daemyung watershed 0.16. In the relationship between the rainfall and peak-flow correlation coefficients(r) were determined to Dalseo watershed 0.9060 and Daemyung watershed 0.5620. In the relationship between the antecedent dry period and flrst flow runoff correlation coefficients(r) were determined to Dalseo watershed 0.7217 and Daemyung watershed 0.2464. In the relationship between the rainfall and watershed loading, exponent values of SS in Dalseo and Daemyung watershed were estimated to 0.54 and 0.496, respectively.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.1 s.24
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• pp.57-66
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• 2007

The purpose of this study is both the variation of hydrologic topographical informations extracted by using WMS and the quantitative effect of rainfalll-runoff simulation due to dividing watershed. Miho stream basin in Geum river was selected by this study. Watershed dividing method are determined by area, channel slope and channel length. Hydrological response of divided watershed using Clark method, SCS method and Snyder method was compared with actual measured flood hydrograph. As a results, area-based watershed dividing method are particularly suitable the hydrologic applications using SCS method. This study can be used as basic data for the phase of the runoff variation in Miho stream basin.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.449-459
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• 2015

The depth of low permeable layer in Jeju Island was analyzed using the geologic columnar section data. The highest low permeable layer was found in center of Mt. Halla and the deepest area was in eastern part of Jeju Island. The study area, Seongsan watershed, is located in the eastern part of Jeju where the low permeable layer showing deep in a northward direction. Based on this analysis, the MODFLOW modeling was performed for groundwater flow of Seongsan watershed. The boundary of Seongsan watershed was set up as a no-flow and the modeling result showed the difference -0.26~0.62 m compared to the observed groundwater level. Meanwhile, MODFLOW model results considering low permeable layer showed -0.26~0.36 m differences compared to groundwater level and indicated more accurate than no-flow method result. Therefore, to interpret the groundwater flow over Seongsan watershed, comprehensive consideration including the low permeable layer distribution below the basalt layer is needed.

• Environmental Engineering Research
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• v.15 no.1
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• pp.49-56
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• 2010

Based on a survey of citizens and data analysis on the environmental status of the Miyun Reservoir watershed, China, the environmental awareness of citizens residing in the watershed and the impacting factors are discussed. The contingent valuation method was used to evaluate the willingness of villagers to pay (WTP) for abatement of the rural domestic pollution and to assess the intensity level of the villagers' desire for improving environmental conditions in the Miyun Reservoir watershed. It was found that rural watershed residents had a fundamental cognitive understanding of the pollution status and protection measures of the Miyun Reservoir. However, based on the survey, local residents had only a small interest in their participation to improve the environmental status of the reservoir, despite their general attitude to protect the reservoir being very positive. Gender and family income were closely associated with the overall attitudes of the population. Public media are the most preferable means for conveying knowledge of environmental protection to people living in the watershed. Increasing the educational level, along with income, are the best ways to enhance the desire of the villagers to improve the environmental quality and management.