Abstract
The authors have had limnological researches in Lake Kizaki several times since 1959 intending to make clear the movement of non-steady currents of such a small lake as Kizaki. They measured water temperature, direction and velocity of wind, and movement of “current drags” as an indicator of the movement of late currents.
The water temperature was measured by a thermister-type thermometer, wind velocity by a Robinson's cup anemometer and water movement by several current drags kept at the depths of 1, 3, 5, 7, 10 and 15 meters.
The authors inquired the distribution of water temperature at each depth as is shown Figs. 3-5, from which they presumed the water movement. Comparing this presumptive movement with that of current drags shown in Figs. 7-9, the following conclusions were reached:
The northern and southern winds which are prevailing all the year round decide the movement of nonsteady current. In the summer season, the northern wind gives more remarkable influence on the currents than the southern wind does, not because of the difference of wind velocity but because of the topography around the lake. In the autumn, the partical circulation period, the movement of currents caused by wind is indistinctly recognized.
The velocities of currents at the surface and the thermocline layer are low, while those of currents between the surface and the thermocline layers and below the thermocline layer are considerably high.
