Abstract
In this study, the effect of discharge on water quality were investigated at Miharu Dam's inflow river, named Otakine river. The relation between AGP (Algal Growth Potential) and water quality was also investigated. From the survey result, the effect of the inflow nutrients load during normal discharge (on fine days) and high discharge (on rainy days) on the algal growth was examined. The following results were obtained: 1) The contribution ratio of the inflow nutrients load during high discharge for algal growth is 11-97% (average 59%). This is higher than at normal discharge. Thus, counter-measuring the inflow nutrients load during high discharge is necessary in order to suppress algal growth in enclosed water areas. 2) The contribution ratio of inflow BAP (Bioavailable Phosphorus) load for algal growth is high, 23-74% (average 46%). Thus, counter-measuring the inflow BAP load is necessary in order to suppress algal growth in enclosed water areas.
