(A) prediction of water quality in accordance with the Han River development project
본 연구는 수도권지역 한강하류에 대한 한강종합 개발 계획에 따른 하천수질을 Streeter & Phelps의 DO Model을 사용하여 예측 평가 한 것이다.
본 조사대상은 팔당하류 고안에서 제 2 한강 인도교까지의 한강본류 31.2㎞를 구간으로 하였다.
팔당댐 하류구간의 갈수량과 저수량에 대하여 유입지천으로부터의 오염물질 합류점을 고러하여 6개의 소구간으로 구분하고 구간별수리수문과 유역지천별 오염물질배출량, 오염물질 유입부하량 및 수질오염도 현황을 조사하고 한강 종합개발 전후의 수질을 예측하였다.
1 자정 관련인자인 탈산소반응계수 K^^1 값은 0.18/day이었고 재폭기계수 K^^2 값은 Ⅰ, Ⅱ, Ⅲ구간은 0.17∼0.28/day Ⅳ, Ⅴ, Ⅵ 구간은 0.59∼1.65/day이었다.
2. 한강보전 종합개발 계획전 현황 수질(1983년)을 예측한 결과는 갈수량에서 DO 5.22∼8.74㎎/ℓ, BOD 1.10∼12.03㎎/ℓ이고 저수량에서는 DO 6.10∼8.74㎎/ℓ BOD 1.10∼8.15㎎/ℓ이며, 개발계획 완성후인 1988년은 갈수량일 때 미처리시의 수질은 DO 4.63∼8.74
㎎/ℓ, BOD 1.10∼14.33㎎/ℓ이며 처리시는 DO 6.97∼8.74㎎/ℓ, BOD 1.10∼7.06㎎/ℓ로 나타났고,
3. 저수량 미처리시의 수질은 DO 5.54∼8.74㎎/ℓ, BOD 1.10∼9.87㎎/ℓ이며 처리시는 DO 7.27∼8.74㎎/ℓ, BOD 1.10∼4.97㎎/ℓ로 수질이 향상될 것이다.
따라서 처리시설 완성후의 장래수질은 DO의 경우 수질환경기준 Ⅰ∼Ⅱ등급, BOD는 Ⅱ∼Ⅴ등급의 범위를 유지할 수 있을 것으로 추정된다.
This study was to predict the water quality of the lower portion of the Han River considering the execution of projected plans for the basin development. The prediction was undertaken by using Streeter & Pholp's mathematical model. The subject of study was the main stream of the Han River from Go - An, near Pal - Dang, 31.2km to the 2nd bridge over the Han River. At the maximum draught and low water flow of Pal - Dang downstream, the basin studied was devided into 6 sectors by considering the influx of pollutants from inflow tributaries.
For each sector, the water flow, pollutants discharge rate of tibutaries and present water quality were investigated and then not only present water quality was determined and but also future quality was predicted, considering the establishment of the treatment facilities according to the plan.
The results are shown as follows :
For the factors of the self purification, the coefficient, K^^1 was 0.18/day and the reaeration coefficient K^^2 was 0.17∼0.28/day in sector Ⅰ, Ⅱ, Ⅲ, and 0.59∼1.65/day in sectors Ⅳ, Ⅴ, Ⅵ
The water quality the completion of the plan predicted that the DO and BOD concentrations would be 5.22-8.74㎎/1 and 1.10-12.03㎎/1 at draught respectively, and 6.10-8.74㎎/1 and 1.10-8.15㎎/1 at low water flows as well.
When the integrated preservation plan of the Han River is achieved in 1988, while the DO and BOD concentrations of the untreated water will be 4.63-8.7㎎/1 and 1.10-14.33㎎/1 at minimum flow, and, for the treated water, 6.97-8.74㎎/1 and
1.10-7.06㎎/1. At low water flow, DO and BOD concentrations of the untreated water will be 5.54-8.74㎎/1 and 1.10-9.87㎎/1, and 7.27-8.74㎎/1 and 1.10-4.90㎎/1, for the treated water.
After the wastewater treatment facilities are completed the future water quality of the down stream of the Han River will be a class Ⅰ-Ⅱ for DO according to the water quality standards and class Ⅱ-Ⅴ for BoD.
This study could be applied to improve the water quality of the Han River in carrying out of the river basin development project.