Abstract
Lake Shinji has a distinctive environment based on the inflow, which the astronomical and meteorological tide causes, of the salt water from Lake Shinji, and the inflow from the Hii River. Recently, the extension construction is planned to defend from overflowing in the Ohashi River that connects Lake Nakaumi and Lake Shinji. It is the important problem that we study about the present mechanism of water environment in Lake Shinji. So, we calculate the estimation of water quantity and salinity fluxes, based on the data observed from summer to autumn in 2003, and examine them in various weather conditions. Furthermore this study focuses on the cause of the variation of the salinity concentration in Lake Shinji. Also, after the inflow of much salt water, it makes the halocline, DO under the halocline often disease in the lake, we state the phenomenon of the variation of DO and the salinity concentration.
