2011 Volume 67 Issue 4 Pages I_1567-I_1572
The continuous monitoring of water quality at Nomura dam is carried out with a water-quality profiling system(YSI Inc.). It is equiped near the aerator and the effect of aeration on water quality is investigated. The sampling time and depth intervals are 2 hour and 1 m, respectively. The measuring items are water temperature, pH, turbidity, DO, Chl and the number of Blue-Green Alga per unit volume. Microcystis aeruginosa migrates up and down diurnally. Namely, it can be found near the water surface early in the morning and at midday exists at about 5m depth.