Estimation of daily cyclic water quality in the Shikinawa Lake

Water quality is one of the main characteristics of water storage reservoirs or lakes. A water quality profile, in both of spatial and temporal variations, plays a very important role in assessment and management of lake water quality. In order to have deeply understanding of the lake water quality parameters, some observation plans were decided for the Shikinawa Lake, in different climate conditions including summer, typhoon occurring time, end of autumn, and before spring. Results of the first observation, which have done in summer, are presented and discussed in this paper. Some important properties of water quality situation of the Shikinawa Lake were obtained and analyzed. Measured data also gave a clearly understanding of relationship among water quality parameters, effects of climate condition and aquatic plant coverage on lake water quality distribution. Besides, periods of activities of convection term and wind induction on water quality were cleared from analyzed data. In further studies, these data will be used as important part of three–dimensional model for lake water quality.