Abstract
Following periods of heavy rain from severe storms and typhoons, water with high turbidity and high levels of suspended matter flows into reservoirs from watershed areas. High turbidity levels may continue to persist for some time. Furthermore, when reservoir water turns cloudy, it can disrupt water purification system and resources for an extended period. This paper, as basic research, measures the movement of high turbidity water through Ogouchi Reservoir in order to control water quality by releasing high turbidity water during heavy rains. We compare suspended solids between normal conditions and periods of high turbidity, and this analysis of suspended solids that flow into the reservoir during rainfall forms the basis of our data. We discuss the causes of turbidity and consider its influence. As a result, we show that the high turbidity in the reservoir is due mainly to clay particles with the size of less than 5μm. Moreover, we confirmed that the suspended solids contain certain amount of phosphorus which is consisted mainly of phosphate ion.
