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Volume 45, Issue 1
Displaying 1-10 of 10 articles from this issue
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Chisato TOMIYAMA, Yasushi KITANO1984 Volume 45 Issue 1 Pages 1-5
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSCalcite was found in the sediment of the Don Juan basin in the Dry Valleys region of Antarctica. In order to clarify the chemical composition of the past pond water, the crystal formation of calcium carbonate from calcium chloride rich solution was studied. The transformation of aragonite into calcite in a calcium chloride solution was also investigated.
The experimental results suggest that calcite in the sediments of the Don Juan basin was formed from calcium chloride water through inorganic processes.View full abstractDownload PDF (703K) -
Hisayuki TERAOKA, Michihiro OGAWA1984 Volume 45 Issue 1 Pages 6-12
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe concentrations and the enrichment factors for Fe, Mn and organic matter in suspended solids, which are scavengers of trace metals in the water, were found to be slightly higher in estuarine water than in rivers, suggesting adsorption of trace elements on particles. In addition, concentrations of trace elements such as Pb, Cu, Zn, Ni, Mn, Cr, Co and P in suspended solids in water column and in the sieved sediments were positively correlated with the amount of organic matter at p=0.1% (n=59, r=0.66-0.89). As to trace elements dissolved in the water, the concentrations of Fe, Cu, Ni, Pb and Cr in estuarine surface waters were slightly lower than in river waters, but Mn, Ag and Zn showed the reverse tendencies. The comparison of concentrations of trace elements in the interstitial water obtained from estuarine sediments with the overlying water indicates a characteristic increase of Mn and Co by factors of 620 and 37, respectively, and a 7.3-15 fold increase of Cr, Cu, Zn, Pb, Ag, Fe and Ni.
Thus, it was found that trace elements carried from river to estuary in the form of suspended solid and dissolved state are removed in small quantities from the water column mainly by flocculation together with organic matter, and again released into the environment from the sediment.View full abstractDownload PDF (1187K) -
Seisuke NAKAMURA, Motoshi TAKEMURA, Yasushi KITANO1984 Volume 45 Issue 1 Pages 13-20
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (1286K) -
Yasuhiko TEZUKA1984 Volume 45 Issue 1 Pages 26-37
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSIn order to clarify the present trophic status of Lake Biwa, the largest, monomictic lake in Japan, seasonal variations of dominant phytoplankton, chlorophyll a and nutrient levels were surveyed for offshore waters of its north (main) and south (subsidiary) basins from February to December 1981.
Annual means of Secchi disc transparency in the north and south basins were 4.8 and 1.7 m, respectively. In both basins, diatoms were most predominant in winter and early spring, and green algae in other seasons. Besides these algae, Uroglena americana and Anabaena macrospora formed dense blooms for short periods. Two peaks of chlorophyll a concentration in the surface water were observed in both basins, one in May and the other in October. Annual mean concentrations of chlorophyll a in the surface waters of the north and south basins were 9.1 and 10.1 g El-1, respectively, while those of total phosphorus were 9.2 and 16.7 g El-1, respectively. High concentrations of nitrate plus nitrite nitrogen were detected in both basins except for three months from August to October. It was concluded that phosphorus was the most limiting nutrient for phytoplankton growth for the most part of the year, but nitrogen seemed to be also limiting during August to October. Trophic degrees of both basins were intermediate between mesotrophic and eutrophic in terms of chlorophyll a and total phosphorus concentrations.View full abstractDownload PDF (1700K) -
Masahiro SAKATA1984 Volume 45 Issue 1 Pages 38-43
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSA sediment core was collected from S Reservoir, which is located in the western part of Okayama Prefecture. The vertical distribution of heavy metals (Fe, Mn, Zn, Ni, Cu and Cd) and fine particles (<37μm) was measured. The heavy metal contents of the sediment core are relatively high in small grain layers. Partitioning of heavy metals into NH2OH HCl soluble, H2O2 soluble and HF soluble fractions has been determined with a selective chemical leaching technique on the sediment samples. The greatest parts of Mn and Cd are contained in the NHOH HCl soluble fraction (mostly iron and manganese oxide and hydroxide coatings on silicate minerals), whereas more than 50% of Fe, Zn, Ni and Cu is present in the HF soluble fraction (silicate lattice). The variations of heavy metal contents in the sediment core are chiefly due to those in NH2OH HCl soluble and HF soluble fractions. Only manganese is significantly enriched in the NH2OH HCl soluble fraction of the settling material collected by the sediment trap near the bottom, probably due to the release of manganese from bottom sediment into overlying water. Manganese oxide and hydroxide reprecipitated under oxic conditions of the bottom water after the release might have been effectively collected by the sediment trap.View full abstractDownload PDF (948K) -
Masaya YASUHARA, Shigemi TAKAYAMA, Yuichi SUZUKI1984 Volume 45 Issue 1 Pages 44-50
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSAn intensive research was conducted in a small headwater basin (0.56 ha) in the Tama Hills to clarify the mechanism of stormflow generation. Field observation was carried out during and after the 130.5-mm rainstorm of Oct. 7-8, 1979.
The relationship between subsurface water behavior and stormflow generation was established at each stage of the rainstorm by using fifty-six observation wells and forty tensiometers. Three contributors to stormflow generation, subsurface stormflow in the A-horizon, saturation overland flow, and flow from the shallow groundwater body, were recognized. A quantitative analysis of the observed results revealed that the subsurface stormflow in the A-horizon was the most important contributor to stormflow generation in the experimental basin. In such a region as Japan, where rainstorms with a total rainfall of more than 100 mm often occur, much more attention should be concentrated on the role of the A-horizon in stormflow generation.View full abstractDownload PDF (1291K) -
Koichi YOSHIMURA, Katsumi HAYASHI, Jiro KAWASE, Kazuro TSUJI1984 Volume 45 Issue 1 Pages 51-60
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe existence of linear alkylbenzene sulfonates (LAS), fatty acids and fats was investigated in the surface water and sediments of several Japanese rivers (the Tama, Ta, Kinu and Tenpaku River). The determination of LAS was carried out by Abbot's methylene blue method and reversed-phase high performance liquid chromatography (HPLC) with a fluorimetric detector. Fatty acids and fats were measured, after prelabelled of fatty acids (or fatty acids in fats) with 4-bromoethyl-7-methoxycoumarine (BMC), by a reversed phase HPLC with a fluorimetric detector. Methylene blue active substances (MBAS) were detected in all river water and sediments samples, while LAS was not able to be determined without the Tama and Ta River. The concentrations of LAS detected in the river water and sediments of the Tama River were trace-0.38 mg El-1 (trace-0.82 mg El-1 of MBAS) and 2.79-10.72 ppm (6.23-31.6 ppm of MBAS), respectively. The concentrations of fatty acids in river water and sediment were 0.005-0.052 mg El-1 and 7.7-426 ppm, respectively, and river sediments contained 8-19 ppm of fats. These fatty acids and fats were estimated to be derived from organisms such as algae and bacteria.View full abstractDownload PDF (1376K) -
Yosuke KISHI, Kunimitsu INOUCHI1984 Volume 45 Issue 1 Pages 61-68
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSFluctuation of the groundwater level and fresh-salt water interface in response to the tide is investigated by using a model in which groundwater is assumed to be composed of two immiscible fluids, fresh water and salt water, in unconfined and confined coastal aquifers. By solving approximately equations of groundwater flow, simple analytical forms are obtained which express the fluctuation of the groundwater level and fresh-salt water interface in response to the harmonic oscillation of the sea level. Equations of groundwater flow are then solved numerically, and the results are compared with simple analytical solutions. An agreement between them is satisfactory. Results obtained from these analyses are summarized as follows : Fluctuation of the groundwater level is almost the same as that predicted from the model in which groundwater is assumed to be composed of only a single fluid. Amplitude and phase lag of the oscillation of the fresh-salt water interface are nearly the same as those of the groundwater level in the case of the unconfined aquifers. In the case of the confined aquifers, on the other hand, amplitude of the fresh-salt water interface is considerably smaller and the phase lag is about 45 degrees compared with those of the groundwater level.View full abstractDownload PDF (1255K) -
Kazuko MORIKAWA1984 Volume 45 Issue 1 Pages 69-78
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSSeasonal fluctuations were studied for water temperature, pH, dissolved oxygen, BOD, COD, NO3-N, discharge, amount of chlorophyll a (Chl. a) +phaeophytin a (Phae. a) and the number of aerobic heterotrophic bacteria in water, and dry weight, amount of Chl. a+Phae. a and the number of bacteria in periphyton in the upstream area of the Tamagawa River in Tokyo, Japan.
The number of bacteria in water fluctuated between 3.0 103 and 1.4 104 cells cm-3. Generally, they are numerous when the discharge was small and vice versa. During the flood stage, in spite of huge flow, the number of bacteria was large. The periphyton of the river bed exfoliated when the discharge was large, and the amount of Chl. a+Phae. a did not increase over 100 mg Em-2. The number of bacteria in periphyton and the amount of Chi. a+Phae. a have a high correlation coefficient (r=0.868). The percentage of pigment producing bacteria rose with the increase of Chl. a+Phae. a, suggesting a bacterial community relating to the epiphytic algae. After exfoliation of periphyton, the number of bacteria did not decrease as much as the amount of Chl. a+Phae. a, suggesting another bacterial community not depending on them. No correlation between the number of bacteria in water and that in periphyton was observed.View full abstractDownload PDF (1607K) -
M. A. KHAN, C. EJIKE1984 Volume 45 Issue 1 Pages 79-80
Published: January 30, 1984
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThis communication lists 45 zooplankton (26 rotifers, 12 cladocerans, and 7 copepods), identified from diverse aquatic habitats in the central part of Nigeria.View full abstractDownload PDF (245K)
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