魚群探知機による木崎湖の湖盆調査

概要

論文の詳細を見る
In the summer of 1962 the authors had some limnological observations in Lake Kizaki using an echo sounding instrument which has rarely been used in Japanese lakes though it has many excellent characteristics. The authors made a map of basin topography and, comparing this map with an old one which was drawn by Dr. Tanaka by means of lead in 1930, some remarkable differences are pointed out as follows : 1) The area of the bottom plain of the lake is larger and deeper, and microtopography of the basin seems to be rather simple these are thought to be due to the sedimentation during late 30 years and the difference of the methods. 2) The delta at the northern end of the lake formed with the deposits of an inflowing river seems to have developed westward a little. 3) The lake shelves were observed in the depth of 10-15 m at the eastern part and 5-10 mat the northern part of the lake. The distribution of the plankton layer was observed also with this instrument as is shown in Fig. 2 the area where the distribution of plankton is dense coincides with the area of high transparency. Finally, this instrument is useful not only for the observations mentioned above but for the research of thermal stratification, tracing of inflowing water, etc. The authors believe it will be used increasingly in limnological researches.