巻号一覧
35 巻 (1974)
- 4 号 p. 127-
- 3 号 p. 91-
- 2 号 p. 53-
- 1 号 p. 1-
35 巻, 1 号
選択された号の論文の6件中1～6を表示しています
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Seiichi KANARI1974 年 35 巻 1 号 p. 1-17
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリーOscillations of surface and interface elevations and velocity have been calculated numerically in using a two layer model of constant depth with 25×62 square meshes of 1 km intervals. In that model, the mean depth of the interface is 17.5m and the density difference between the upper and lower layers is 2.5×10-3g/cm3 corresponding to the temperature difference of 13°C.
Linear hydrodynamic equations for the equivalent volume transport and the equivalent elevations were integrated by means of an implicit method, taking into account of wind stress, bottom stress and CORIOLIS force.
In the present numerical experiments, the four cases of duration time were treated, 450 minutes (NW-(1)) and 1200 minutes (NW-(2)) for NW-wind and 450 minutes for SW-wind and ESS-wind, to which the constant wind speed of 5m/sec was applied.
From the results of FOURIER spectrum analysis for the calculated time series of elevation and velocity at various sampling positions in the model lake, it was found that the long period internal KELVIN waves progressing along the lake shore in the anticlockwise direction exist with the same period as that in the case of no rotation of the earth, and that the mean lake currents consisted of two or three gyres, are essentially affected by geostrophic condition, as usually observed in real Lake Biwa.抄録全体を表示PDF形式でダウンロード (1818K) -
A Tributary to the Cochin Backwater SystemP.S. JOSEPH1974 年 35 巻 1 号 p. 18-24
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリーThe river water near the industrial belt showed very high concentration of plant nutrients especially of inorganic phosphate and nitrite. They were above the limit of water pollution and were responsible for eutrophication. Dissolved silicate in the river water was not affected by the industrial discharges.
The sediments along the river bed were sandy except near the outfalls of the effluents where the sediment is muddy and of a milky colour. Macrobenthos were absent in the vicinity of the industrial complex except near the outfalls of the wastes where certain species of isopods and polychaetes were adapted to the polluted environment even though the water column at all stations were well aerated by the river flow.抄録全体を表示PDF形式でダウンロード (885K) -
吉武 嵯紀子1974 年 35 巻 1 号 p. 25-31
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリーThe twenty-four larvae of Chironomus sp. treated in this paper were collected in August 1967 on the bottom from 2m to 11m deep of Lake Yunoko.
The dominant species of algae determined in the digestive tracts of the larvae, together with the individual number of Chironomus from which they were found, are shown as follows : Asterionella formosa 16, Fragilaria pinnata 14, Melosira italica f.curvata 14, Fragilaria spp., 9, Fragilaria crotonensis 7, Fragilaria construes 7, Melosira sp., 1, Pinnularia gibba 1. of Chironomus sp., respectively. All these species except Pinnularia gibba are regarded as planktonic species.
Comparing the contents of digestive tracts by means of the values of C'2, the individuals of Chironomus obtained from the same place were often more similar than those collected from the other places, while the values of C'2 between the all individuals were shown as 0.53 which indicated unnoticeable similarity.
Though the dominant species of the micro-algae in the upper layers of the bottom of the lake showed a simple appearance in composition, those found in the digestive tracts of Chironomus sp. seemed to be complex. This matter of fact was considered to be due to the following reason.
If the micro-algae except Fragilaria pinnata formed patches and their diameters were so small as only a part of which was possible to be contained in the quadrat (25cm2), the micro-algae forming patches were averaged. They would be likely to induce such a consequence that small number of algal individuals became distributed on an average in a case of using quantitative method with a quadrat (25cm2) adopted to investigate the micro-algae in the upper layers of the bottom.
In fact, it is extremely probable that Chironomus takes the micro-algae forming patches. In this case, the dominant species might appear to be different between the micro-algae observed in the upper layers of the bottom of the lake and those contained in the digestive tracts of Chironomus larvae.
On the other hand, it would be possible to consider that the larvae of Chironomus take the micro-algae not only on the surface layer but also in the deeper layers of the lake-bottom. In such circumstances, there might be a difference in regard to the dominant species of algae between in digestive tracts and those found on the surface layer of the bottom.抄録全体を表示PDF形式でダウンロード (1078K) -
北川 礼澄1974 年 35 巻 1 号 p. 32-41
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリー1. Lakes Tyuzenji-ko, Yuno-ko, Suge-numa and Maru-numa were investigated in 1972 and 1973 in regard to their bottom fauna. The results obtained were compared with the data by MIYADI during the years from 1928 to 1930. They are shown in Table 10.
2. Lake Tyuzenji-ko : Micropsectra sp. (A), which is a characteristic species of oligotrophic lakes, occurred on the bottom between the littoral and profundal zones. Tubifex sp. is abundant in the profundal zone ; an azoic zone does not exist at present.
3. Lake Yuno-ko : Though Tubifex sp. and Chironomus plumosus occurred in the profundal zone where oxygen was absent in summer stagnation period, some of them seemed to move to the shallow bottom. This lake belongs to “eutrophic Plumasus lake” at present.
4. Lake Suge-numa : In the main basin Kitamata-numa Micropsectra sp. (A), Spaniatoma sp. (B-5) and Tubifex sp., though not abundant, were found in the profundal zone. This lake belongs to “oligotrophic Tanytarsus lake” as it was so at the time of MIYADI's investigation. As for the auxiliary basin Shimizu-numa there was found an azoic zone existing partly in the profundal zone. Some kinds of chironomid larvae occurred in the littoral zone.
5. Lake Maru-numa : Chironomus plumosus larvae are abundant on the shallow bottom. Tubifex sp. is distributed widely in the profundal zone.抄録全体を表示PDF形式でダウンロード (1421K) -
塩入 清嗣1974 年 35 巻 1 号 p. 42-49
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリーKama-ike is a small but deep mountain lake in sickle shape that lies at an elevation of 1, 190 m in the northernmost part of Nagano Prefecture in Central Japan. It lies at 36°51′N. Lat. and 137°58′E. No detailed survey has been made since Dr. A.TANAKA sounded this lake in 1919 for the first time. The writer's investigations were carried on in this lake in August 1972, in regard to re-soundings as well as to some limnological features. The following morphometrical features were obtained by the 139 soundings in total : the superficies of the lake 27, 100m2, excluding 175m2 of the island areas ; the greatest depth 16.2m and the mean depth 6.87m, and the shore development 1.71. Its volume is calculated as 1, 950, 000m3. The results indicate that this lake has become shallowed by 1.8m during the fifty-one years since TANAKA's first soundings. This means that the decrease of depth has progressed at the rate of 1.5cm a year. The thermocline was seen at the layer of 2-6m deep, at which zone the dissolved oxygen was supersaturated in summer. In the hypolimnion the amount of dissolved oxygen decreased greatly as indicating the progress of eutrophication to a certain extent. The pH values were 7.4 at the lake surface, then gradually lowering as 6.8-6.9 and became reversed to 7.0 in the bottom water.抄録全体を表示PDF形式でダウンロード (1218K) -
小島 貞男1974 年 35 巻 1 号 p. 50-51
発行日: 1974/01/30
公開日: 2009/10/21
ジャーナル フリーPDF形式でダウンロード (811K)
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