Total water pollution load management(TWPLM) seeks to harmonize conservation and development by allowing regional developments to be carried out in an eco-friendly manner and within the scope of achieving the desirable water quality. Water pollutant sources are managed so as to keep the total amount of pollutants in public watersheds within a certain level or total allowance in accordance with target water quality goal. With relation to the basic guideline under the Special Act on the Water Resources Management and Community Support for Watersheds, the load from the land should be determined by the classification of rainy and dried season respectively. Objective loads of abatement applied in the 1st planning period(2004∼2010) are set up standards by low flow condition(Q275) without considering the change of flow, while allowable wasteloads are estimated by the criteria of daily mean precipitation 10 mm, as critical standard for the division of surface runoff load. Even though the standard flow conditions to meet the goal of water quality at the end of unit watershed are low flow, but it might be considered to set up drought flow condition(Q355) for the improvement of water quality. Also the objective loads for abatement to meet the target water quality should be calculated without the effect of non-point sources from the land.

본 연구에서는 천수만유역을 대상으로 오염부하량을 산출하고 연안을 관리하는데 Gli의 활용방안을 연구하였다 오염원 관리의 단위인 유역 범위는 하계망 분석을 통하여 하천의 길이, 차수, 유역면적 등을 고려한 후, 수치지도에서 DEM을 이용하여 정성적인 방법으로 선정하였다. 천수만 유역은 총 6개의 단위유역과 33개의 소유역으로 구분되었으며, 단위유역과 소유역별 오염부하량의 차이가 크게 나타났다. 각 유역에서 산출된 오염부하략은 오염원 관리 측면에서 유역구분의 효용성을 검토하는 자료로 활용되며, 수질측정 및 환경기초시설의 입지 선정에도 이용 가능하다.

In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20～100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DIN and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.

The purpose of this study is to investigate the characteristics of water quality in Jeju harbor and to estimate pollutant loadings discharged into Jeju Harbor. To know characteristics of water quality in Jeju harbor and pollutant loadings of Sanzi river, we have investigated from August, 2000 to May, 2001. The results showed that the concentrations of COD, DIN and DIP were in the range of 1.00～4.85㎎/L (mean 2.15㎎/L), 2.14～74.0㎍-at/L(mean 12.20㎍-at/L) and 0.52～4.00㎍-at/L(mean 1.18㎍-at/L), respectively. These values were under Ⅲ class of seawater quality criteria. The ratio of nitrogen to phosphorus was lower than 16 except for Station 1 in Jeju harbor. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in Jeju harbor. The mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. The results of estimating pollutant loadings at Sanzi river are 0.30 ton/day for COD, 300㎏/day for DIN and 18.0㎏/day for DIP, respectively.

The Keum river has been utilized for drinking water supply of several city including Kunsan city and is deepening pollution state due to numerous municipal and industrial discharges. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The predict of water quality has important meaning for management of water quality pollution of the Keum river. The purpose of this study will manage and predict water quality of the Keum river using QUAL-2E model considering the autochthonous BOD. The estimation of autochthonous BOD represented that the relationship between BOD and chlorophyll a. The regression equation was shown to be autochthonous BOD=β5×chlorophyll a. The results of this study may be summarized as followed; The QUAL-2E model was calibrated with the data surveyed in the field of the study area in June, 1998. The calculated value by QUAL-2E model are in good agree to measured value within relative error of 7.80∼20.33%. Especially, in the case of the considering autochthonous BOD, the calculated value of BOD were fairly good coincided with the observed values within relative error of 15%. But the case of not considering autochthonous BOD, relative error of BOD was shown to be 43.2%. In order to attain Ⅱ grade of water quality standard in Puyo station which has a intake facility of water supply, we reduced to the pollutants loading of tributaries. In the case of removed 100% BOD of tributaries, the BOD of Puyo station was 4.07㎎/ℓ, belong to Ⅲ grade of water quality standard. But in the case of removed 88% nutrient of tributaries, it was satisfied to Ⅱ grade of water quality standard as below 3㎎/ℓof BOD. For estimation of autochthonous BOD in Keum river, we are performed simulating in accordance with reduction of nutrient load(50∼100%) under conditions removal 90% organic load. Occupancy of autochthonous BOD according to nutrient loading reductions were varied from 25.97∼79.51%. Occupancy of autochthonous BOD was shown to be a tendency to increasing in accordance with reduction of nutrient loading. Showing the above results, the nutrient that one of the growing factor of algae was important role in decision of BOD in the Keum river. For the water quality management of the Keum river, therefore, it is necessary to considering autochthonous BOD and to construction of advanced sewage treatment plant for nutrient removal.