Supply Effect of Nutrient Load Flowing to Shido Bay by Open Floodgate

摘要

Benten River has a floodgate for disaster prevention. We haveinvestigated the effect of the water supply from Benten River due to thefloodgate opening on the water qualities in Shido Bay. Average valuesof salinity, turbidity and chlorophyll a to the deep direction at the innerbay were directly influenced on the floodgate opening. Theconcentration of dissolved inorganic nitrogen (DIN) and dissolvedinorganic phosphorus (DIP) at the inner bay did not increase to inflowof the freshwater. From results obtained, it was considered that thefloodgate management was important to supply nutrients.