IMPACTS OF WIND ON THE SALINITY IN THE CONNECTED BRACKISH LAKES, SHINJI AND NAKAUMI

Abstract

 The effect of wind on the salinity of the connected brackish lakes, Lakes Shinji and Nakaumi, was evaluated over the recent ten years. The water quality of the lakes was predicted by reproducing the present conditions and reducing the wind velocity to 50% of the present conditions. The reduced wind velocity led to a decrease in the surface mixing in the two lakes. In particular, the significant increases in the salinity of the lower layers of both lakes were predicted. Moreover, a multiple regression analysis was conducted on the amount of water exchange among two lakes and the sea. The results showed that the effect of wind-induced flow by strong winds on water exchange was limited in time and that the gravidity-induced flow by the change in water level due to the blowing effect was more important than the wind-induced flow.