아라천 수질변화 예측 및 수리거동 특성 연구

The purpose of this study is predicting water quality change of Ara River depeding on the case of hypothetic scenario that all Gulpo River flow inflow to Ara River. In-addition, Suggesting minimization method by effect of Gulpo River inflow by understanding hydraulic flow properties in streams are performed. The hypothetic scenario of Gulpo River''s inflow are consisted as removal of rubber-weir of Gyulhyeon-weir with elimination of concrete-weir(S2) on not(S1) and compare with current condition(S0) of Gyulhyeon-weir. As a result of prediction of water quality change by scenario as follows, range of variation of S1 : TOC -1.1 ~ 19.1%, Chl-a -2.8 ~ 21.0%. range of variation of S2 : TOC -1.1 ~ 18.9%, Chl-a -2.6 ~ 20.8%. As a result of Drifter experience, Operating condition of flowing in and out at once a day are showed distance of surface layer are increased 1~2 km/day to 5~12 km/day. but inflow rater of Seawater are decreased average 14.5 m3/s to 10.4 m3/s(about 28%) then condition of flowing continually twice a day. In conclusion, The maintaing method of transport time of kinetic energy as same direction even less water-flow are effective for reducing retention time on surface layer containing high contamination rate by maximizing influence of density current as Ara River salinity layer. Examination of watershed connection for minimizing effect of water quality of both water-shed by a various water flowing method within improvement of water quality of Gulpo River is possible by this study.