무등산 계곡수 유입을 통한 광주천 수질 개선 방안에 관한 연구

A Study on the Improvement Plan of Gwangju-cheon Water Quality by the Inflow of Mt. Mudeung Valley Water

무등산에서 발원하여 광주천으로 유입되던 수많은 계곡수가 합류식 하수관거로 유입되면서 광주천의 건천화와 수질 악화가 심화되었다. 본 연구는 하수처리장으로 유입되는 광주천 유역의 무등산 계곡수를 수원으로 활용하여 실개천을 조성하는 방안에 대해 연구하였다. 먼저, 100 m3/일 이상의 유량을 보이는 4개 지점의 유량 및 수질 조사 결과 지점별로105~2,721 m3/일의 유량을 나타냈으며, 평균 수질은 BOD5 0.3~1.6 mg/L로 나타났다. 만약, 갈수기 유량 1,500 m3/ 일의 실개천을 조성한 후 광주천 남광교 지점으로 유입시킨다면, BOD 7.3%, COD 6.5%, T-P 5.8%, T-N 5.2%의개선 효과가 있을 것으로 예측되었다. 또한, 계곡수 유입에 의한 하수처리장 유량 부하 부담이 줄어들고, 하수처리 비용이 절감되며, 도심 속 수변 amenity 창출에 의한 Blue-Green-Network (BGN) 구축의 토대가 될 것으로 판단되었다.

Numerous valley waters originating from Mt. Mudeung and flowing into Gwangju Cheon flowed into the confluence-type sewage conduit, the Gwangju Cheon became dry and water quality deteriorated. In this study, a method to create a stream was studied by using the valley water of Mt. Mudeung in the Gwangju cheon that flows into the sewage treatment plant as a water source. Flow and water quality surveys were investigated at four points with meaningful flow quantity. As a result, it showed a flow quantity was 105~2,721 m3/day at each point. And the average water quality was BOD5 0.3~1.6 mg/L. If a stream with a flow quantity of 1,500 m3/day is created during the dry season and then flows into the Namgwang bridge of Gwangju cheon, it is predicted that there will be improvements in BOD 7.3%, COD 6.5%, T-P 5.8%, and T-N 5.2%. In addition, it was determined that the load on the flow quantity of the sewage treatment plant due to the inflow of valley water would be reduced, the cost of sewage treatment would be reduced, and it would be the basis for BGN construction by creating waterside amenity in the city.