• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.149-154
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• 2003

The characteristics of pollutant loads from the various sources and seawater quality in Kwangyang Bay were evaluated. Total flow rate was estimated to be $10,868,066.8 m^3/day$ with a flow rate of R2l (the Seomjin River) as the highest one. Total COD, TN and TP loads of the input rivers and the ditches were about 27,591.8, 25,029.6 and 586.4 kg/day, respectively. Wastewater discharging loads was the greatest contributors to pollutant loads in the inner part of Kwangyang Bay. COD values in the inner part of the bay was over 3.0 mg/L, which exceeded the seawater quality criteria III of Korea. The average values of DIN and DIP were 8.62 ${\mu}gN/L\;and\;1.26\;{\mu}gP/L$, respectively. The limiting factor for algal growth was DIN. In he total discharging loads of the watershed from unit loading estimations, BOD, TN and TP were 9,132.3, 2,727.2 and 304.2 kg/day, respectively. In addition, municipal sewage by the population as pollution sources and the city of Kwangyang as administrative district had the highest loads. For a appropriate water quality recovery of Kwangyang Bay, it is suggested that it is essential to estimate reduction rate of total pollutant loads by water quality modeling.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.695-705
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• 2006

This study was carried out to make a basic information for establishment of countermeasures against water pollution of Hoengseong watershed, accordingly we investigated the characteristics of pollutants discharge and estimated the unit loads from Hoengseong watershed. Seven sites (S1~S7) were selected for sampling and samples were taken 4 times during the dry and rainy seasons, respectively. During rainfall events, measured site mean concentration (SMC) ranges of $BOD_5$, $COD_{Mn}$, TOC, SS, Turbidity, T-N and T-P were 0.8~1.3 mg/L, 2.3~6.3 mg/L, 1.284~2.110 mg/L, 3.4~69.3 mg/L, 2.36~52.68 NTU, 1.243~1.669 mg/L and 0.025~0.070 mg/L, respectively. And the calculated annual unit loads of $BOD_{5}$, $COD_{Mn}$, SS, T-N and T-P in Hoengseong watershed were 1.327 kg/ha/yr, 7.349 kg/ha/yr, 87.075 kg/ha/yr, 1.848 kg/ha/yr and 0.103 kg/ha/yr, respectively. It was difficult to directly compare the unit loads proposed in this study with the estimated existing those. Because the unit loads in this paper were estimated not by land use types, but by complex land use of non-urban area. From the survey results, they showed that the unit loads in Hoengseong watershed were similar to those exisiting in the forest area, and showed lower than those existing in the paddy/dry field.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.481-493
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• 2009

This study was conducted to performance appraisal of Total Maximum Daily Loads (TMDLs), especially in terms of performance on development & reduction plan and water quality status of unit watershed. Because load allocations for pollution sources were predicted redundantly by uncertainty of prediction, TMDLs master plan has been frequently changed to acquire load allocation for local development. Therefore, It need to be developed more resonable prediction techniques of water pollution sources to preventing the frequent change. It is suggested that the reduction amount have to be distributed properly during the planning period. In other words, it has not to be concentrated on the specific year (especially final year of the planning period). The reason why, if the reduction amount concentrate on the final year of the planning period, allotment loading amount could not be achieved in some cases (e.g., insufficiency of budget, extension of construction duration). If the development plan was developed including uncertain developments, it is necessary to be developed reduction plan considered with them. However, some of the plans in the reduction plan could not be accomplished in some case. Because, it is not considered financial abilities of local governments. Consequently, development plan must be accomplished to avoid uncertain developments, and to consider financial assistance to support the implementation of effective plan. Water quality has been improved in many unit watersheds due to the TMDLs, especially in geum river and yeongsang/seomjin river.

• Environmental Engineering Research
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• v.17 no.1
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• pp.47-56
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• 2012

A long-term nationwide nonpoint-source pollution monitoring program was initiated by the Ministry of Environment Republic of Korea (ME) in 2007. Monitoring devices including rain gauges, flow meters, and automatic samplers were installed in monitoring sites to collect dynamic runoff data in 2008-2009. More than 10 rainfall events with three or more antecedent dry days were monitored per year. More than 10 samples were collected and analyzed per event. So far, five land use types (single family, apartments, education facilities, power plants, and other public facilities) have been monitored 23 to 24 times each. Characterization of the runoff from different land use types will aid unit load estimation in Korea and hopefully in other countries with similar land use. The monitoring results will be reported regularly at national and international levels.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.426-435
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• 2012

The variation of stream flow is the one of the most important factors which influence on that of water quality in the unit watershed. The target water quality goal is established and permissible load is allotted in the base of the standard flow condition along with its water quality for the management of Total Maximum Daily Loads (TMDLs). A standard flow selected could cause problems in the load allotment if it was not properly arranged. This study reviewed the acquisition of water quality data, the self-variation and the retainability in water quality on the specific flow conditions. This study also proposed the median and the adjusted average flow condition out of general flow conditions as alternative standard flow conditions. It is considered that the alternatives can make the water quality data easily acquired and the water quality representativeness more enhanced on the standard flow conditions.

• Journal of Wetlands Research
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• v.10 no.1
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• pp.69-75
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• 2008

Toll-gate in highways often received the pollution impact from transportation/vehicular activities. Thus, concentrated pollutants carried by stormwater runoff are directed to nearby streams affecting the water quality and ecosystem. In order to determine the environmental impact on nearby waterbodies and predict the future impact by stormwater runoff, the unit pollutant loads from various landuses are really important. This research was performed to characterize the stormwater runoff and to provide the unit loads from Toll-gate landuses in Korea. The monitoring was conducted at toll gate locating in Gaeryoung City during 2006-2007. The water quality parameters including TSS, COD, DOC, TN, and TP were analyzed and also the flow rates were measured during the monitoring. In this paper, EMCs will be calculated by using the monitored water quality concetraions and flow rates, which will be used to determine the unit pollutant loads from the toll-gate of highway.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.279-288
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• 2010

The water quality variations or changes are closely relevant to the characteristics of unit watersheds and have an effect on the attainment of their water quality goal. This study was conducted to analyze the water quality distribution and its change patterns of unit watersheds in Nakdong river basin. It revealed that 25 unit watersheds out of 41 showed the normality in water quality. Most of unit watersheds had a considerable variation in water quality, especially in the season of spring and summer but a little in terms of flow rate. Annual relative differences in water quality ranged from 13.0 to 26.6% with the maximum of 75%. 28 unit watersheds (62%) had the tendency to decrease in water quality as the flow rate increased while 13 (38%) to increase. The extension of standard flow led to considerable differences in water quality depending on its ranges, which meant uncertainties might be included in the process of TMDL development. It is suggested that annual average flow rate should be chosen as a standard flow in the area where the water quality change has little relation to the flow rate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.11 no.1 s.22
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• pp.71-76
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• 2005

The purpose if the study is to apply GIS technique to sample area, Choensoo-Bay basin for an efficient and practical coastal zone management if pollution control. The basins, Unit if pollution control, are selected with qualitative analysis using DEM after considered river length, degree and area of basin through channel network analysis. Choensoo-Bay basin is divided with 6 zones to 33 subordinate zones. It is found to be a big difference of pollutant loads in each zone. The pollutant loads use to review for efficient zoning. And also the result apply to measurement of water quality and building for environmental infrastructure.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.291-296
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• 2008

Pollutant unit load developed by Ministry of Environment (MOE) in 1995 has been a tool commonly used for water quality management and environmental policy decision. In spite of the convenience of the method in application, the shortcoming of the method has been criticized especially for nonpoint source pollution from paddy field. In this paper the estimation procedures of pollutant unit load from paddy field in the major river basins (Han, Nakdong, Geum, and Youngsan river) were investigated, and some suggestions of improvement measures of the unit-load estimation were made. The investigation showed that the distributions of rainfall, run-off, and run-off ratio, which are the most important factors affecting discharge amount of pollutants, were not similar among river basins. Such differences seemed to result in a greater unit loads estimation at Han river and at Nakdong river watersheds compared to the others. Therefore, it is not likely to be rationale to compare unit load among the watersheds without consideration of such differences. We conclude that estimation of unit-load through an intensive monitoring of pollutant discharge is crucial for better estimation of unit-load. When such an intensive monitoring is not easy due to labor and expense restriction, we suggest that unit-load should be estimated based on the storm-events which is a representative rainfall-runoff event of the area.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.66-73
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• 2013

Total Maximum Daily Loads (TMDLs) system was introduced to manage pollution load of watershed and to improve water quality of unit watershed so that it is possible to protect dringking water soureces. Load allocation observation is the most important factor in TMDLs system. Because if load allocation is not observed, it is difficult to achieve water quality goal of unit watershed. Also it is impossible to improve water quality of the drinking water sources. Therefore it is necessary to apply some kind of sanctions (penalty) in case of excess of load allocation. The sanctions have to be, however, applied differently based on various reduction plan types, i.e., using the reduction load planed in 2nd phase, delay the completion, additional reduction in 2nd phase, error of the pollution sources, etc. Moreover, the penalty load should be properly imposed, lest it should be overburden the provence. The reduction load trade inter province must be restrictively permmitted only the same unit watershed.