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Volume 35, Issue 4
Displaying 1-7 of 7 articles from this issue
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Heat budget in both basinsKatumi ITO, Iwao OKAMOTO1974 Volume 35 Issue 4 Pages 127-135
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSLake Biwa-ko consists of two basins. The water volume of the northern basin is about 140 times as much as that of the southern basin. The computation is made for the monthly change in heat content of the northern basin and for the net radiation at the lake surface. As the adventive heat budget may be ignored in case of the northern basin, the monthly heat flux caused by the evaporation is determined on the basis of equation of heat budget and BOWEN ratio. The monthly evaporation values total to approximately 770 mm/year. The wind factor for evaporation coefficient, f (W), seems to be given in formula of 0.017W in Lake Biwa-ko. It has been found that the advection term in heat budget takes an important role in case of the southern basin and that the heat exchange between both basins, caused by the internal seiche or the density current, cannot be neglected.View full abstractDownload PDF (1280K) -
Seiichi KANARI1974 Volume 35 Issue 4 Pages 136-147
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSSeasonal change of the internal seiches' period will be treated by the spectrum analysis of the continuous temperature records which were obtained from the thermistor-buoy stations in Lake Biwa.The dominant period almost coincides with theoretical one which can be derived from a longitudinal internal seiche in a two-layered rectangular lake, but the observed spatial phase difference and amplitude cannot be explained reasonably by the concept of a simple longitudinal internal seiche. They rather correspond to the rotating internal KELVIN wave, which was found out from the numerical experiments in the preceding paper (6).
The results of the “Round Cruise Survey” of the thermocline of Lake Biwa, which was carried out during the period from Aug. 9 to Aug. 13, 1973 shows that the dominant internal oscillation has a rotatory nature, that is, the high water region rotates along the lake shore in the anticlockwise direction with an apparent phase velocity of 2.2km/hr (in August). Such a rotatory behavior of the internal oscillation enables us to interpret reasonably the results of the spectrum analysis of the temperature records.View full abstractDownload PDF (1552K) -
Yasuo MARUYAMA1974 Volume 35 Issue 4 Pages 148-154
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSInvestigations were made during the period from June, 1971 to Jan., 1972 on the load of pollution into the marine area of Mikawa Bay from all rivers around the Bay with the following results.
1. Average total amount of river water entered into the Bay during the period was 290 m3/s and the total loads of pollution were 1.3kg E BOD/s, 2. 1kg E COD/s and 0.5kg E T-N/s.
2. Loads of pollution by rivers are scarcely influenced by the values of BOD, COD and T-N respectively, but are governed entirely by the quantities of river waters.
3. The loads of BOD of the large rivers, Toyokawa and Yahagi, amount to about 50% of the total one of all rivers.View full abstractDownload PDF (972K) -
Naomasa KOBAYASHI1974 Volume 35 Issue 4 Pages 155-161
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESS1. Pond snail (Radix auricularius Japonicus (JAY)) eggs were used as an indicator organism : indicatory stages and states were normal cell division to larva and anomalies such as stop, retard or deform of development.
2. Several bioassays were made to measure the water pollution around Osaka City in using pond snail eggs. Most of the river waters examined are polluted, and in particular markedly in the River Daini-Neya-Gawa. No cleavage of eggs occur in the heavily polluted water discharged from the Konohana sewage disposal plant.
3. Heavy metals induce stop, retard or deform of development, etc. Various chemicals other than heavy metals also induce the same phenomena.
4. The bioassay to measure water pollution using pond snail eggs has such advantages as simplicity, easiness, speed, high sensitivity, clearness of indicatory features, uniformity, and higher accuracy. The method is available in any season of the year when rear under control.
5. The ranking of inhibitory degrees of polluted water samples upon the development of the egg is proposed tentatively as seen in Table 4.View full abstractDownload PDF (2004K) -
Norizumi KITAGAWA1974 Volume 35 Issue 4 Pages 162-171
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESS1. Lakes Towada-ko, Tazawa-ko, Inawasiro-ko, Akimoto-ko, Onogawa-ko, Hibara-ko and Numazawa-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 1932. They are shown in Table 14.
2. Lake Towada-ko : Micropsectra sp. (A), a characteristic species of oligotrophic lakes, is dominant in the profundal zone deeper than 300 meters. This lake belongs to an oligotrophic Tanytarsus (=Micropsectra) lake.
3. Lake Tazawa-ko : No macroscopic animals occurred on the bottom deeper than 400 meters. The profundal zone of this lake is azoic. In the littoral zone some kinds of chironomids were found, though not abundant.
4. Lake Inawasiro-ko : Tubifex sp, is the dominant species in the profundal zone. Chironomus bathophilus occurred on the zone shallower than 40 meters.
5. Lake Akimoto-ko : Tubifex sp. and C. plumosus, though not abundant, occurred in the profundal zone. This lake belongs to a mesotrophic Plumosus lake.
6. Lake Onogawa-ko : Corethra (=Chaoborus) sp., C. plumosus and Tubifex sp. were found in the profundal zone where dissolved oxygen was absent in the summer stagnation period.
7. Lake Hibara-ko : At present C. bathophilus occurs instead of C. plumosus which was the dominant species of the bottom fauna at the time of MIYADI's investigation.
8. Lake Numazawa-numa : T, genuinus and Sergentia sp., which were abundant in the profundal zone in 1930, do not occur at present ; only Tubifex sp, occurs there.View full abstractDownload PDF (1401K) -
Tsukasa KOMATSU1974 Volume 35 Issue 4 Pages 173-182
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSEcological studies were made of the aquatic insect communities in the Tenryu River, Central Japan, in the summer of 1967, with special reference to their composition, the biotic index calculated according to BECK-TSUDA's method. During the years from 1968 to 1969, the seasonal change of aquatic insect communities and the biotic index were studied in the area of polluted water by wastes from the KP pulp plant located in the upper reach. The results are as follows
1. In July, 1967, the aquatic insect fauna was poor in the Tenryu because of various reasons. The net-spinning caddis-worm Hydropscyche ulmeri was dominant at most stations there.
2. The aquatic insect communities were composed of 20 to 29 in the number of species, of which the maximum numbers attained in May, the minimum in July, at the station Tatsuno-A (relatively clean water) in the samples by using a quadrat (50×50cm). The number of species at Tatsuno-B (150 meters down from the KP pulp plant) was 2 to 4, and that at Shinmachi (2 kilometers down from the same plant) was 8 to 14.
3. The individual numbers and standing crops of many species of aquatic insects became minimum in summer in quadrat samples at Tatsuno-A, and increased from autumn till winter.
4. The seasonal change of the biotic index was 37 to 53 at Tatsuno-A, 3 to 7 at Tatsuno-B, and 12 to 25 at Shinmachi.View full abstractDownload PDF (2064K) -
[in Japanese]1974 Volume 35 Issue 4 Pages 183
Published: October 30, 1974
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSDownload PDF (599K)
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