River In Tokyo Research Articles

Stormwater Runoff of Hydrocarbons in the Tama River Basin in Tokyo (Japan) and Their Fate in the River

Stormwater runoff pollution in urban areas has a significant impact on the aquatic environment. The Nogawa River, which is a tributary of the Tama River in Tokyo, runs through a residential district. At high water levels, more aliphatic hydrocarbons were found in the river water than at normal water levels. It seemed that the hydrocarbons in the water at normal water levels originated from gray water, and those at high water levels were from automobile emissions and/or resuspended bottom sediment. Concentrations of polycyclic aromatic hydrocarbons (PAHs) were negligible in river water at both normal and high water levels whereas they were high in the bottom sediment. It is most probable that the PAHs originated from sources other than automobile emissions.

A Study for Statement of River Environment

Not only Flood control functions, Water utilizatoin functions but also Functions of River Environment has been to very important. Because of, River environment function has influence on Life environment, Mental climate of human being. Firstly, In the present report, We wish to describe the Water Familiarization Functions. We had divide for form of bank, Materials of bank, Water quality, Water quantity, Bioiogical indicator etc. in environmental factor of River for a Synthetic river environment statement.How to Statement of River environment is methods of numelical system and Principle component analysis. An object of River is 25 rivers in Tokyo and, We had draw maps of Synthetic River environment statement by the charts. As a result of We could extract a preponderant rivers for improvement of river environment and countermeasure of river purification from 25 rivers.

大和川河川敷におけるシバオサゾウムシの発見

The zoysiagrass billbug, Sphenophorus venatus vestitus CHITTENDEN (Coleoptera: Curculionidae), which is inferred to be introduced into Japan from the United States, has been found occurring in Fukuoka, Hyogo and Tokyo Prefectures since the first discovery at a golf course in Okinawa Prefecture in 1979. Five adults (2 females and 3 males) of this species were captured by using pitfall traps at the bank of Yamato River in Osaka and Nara Prefectures in 1986, 1988 and 1989 (Table 1). This may be the first discovery of this species in both prefectures and the second record from the river bank after the record from the Tama River in Tokyo.

A COMPARISON OF CONTINGENT AND HEDONIC APPROACHES FOR THE ESTIMATION OF THE IMPROVEMENT OF RIVER ENVIRONMENT

The purpose of this paper is to discuss the applicability of the contingent and hedonic approach in order to identify the benefit of marginal emvironmental improvement of Nogawa River and Ichinoe-sakai River in Tokyo. First the study constructs a hedonic price function of land which includes river side park and water quality as major valiables. Second the study surveyes residence Willingness to Pay for these improvement using paired comparison questionnaire method and identifies bit price functions. Third this paper analyzes the discrepancy of the values estimated by two methods. The study finally finds 1) the benefit of river side park improvement is 11 to 19 thousand yen/m2. and discrepancy of the method is minimal. 2) Water quality improvement is 7 to 28 thousand yen/m2.

東京の川

東京の川

Differences in plating efficiency of bacteria from river epilithon sampled from upper and lower surfaces of artificial substrata

The bacterial generic composition of biofilms was investigated by determining colony-forming units on 1/2 PYG (peptone, yeast extract, and glucose medium) agar plates. The biofilms developed on the upper and lower surfaces of artificial substrata submerged in river water at Unazawa in the Tamagawa River in Tokyo, Japan. Greater variation in the number and generic composition in platable colonies was obtained on the upper surface of an artificial substratum than on the lower surface. This variation corresponded to the variation in algal biomass. Accompanying the growth of the algae, specific bacteria commensal with the algae proliferated on the upper surface. The biofilm exfoliated when the surface density of chlorophyll was 11.2 μg·cm(-2). When the biofilm exfoliated, the bacterial community accompanying the algae also exfoliated, and the bacterial composition altered. The bacterial composition after exfoliation resembled that observed on the lower surface. The generic composition on the upper surface soon after it was initially submerged resembled that observed in the river water. The bacterial generic composition on the lower surface of the artificial substrata did not change greatly throughout the investigation because of the constant environmental conditions. The difference between the bacterial generic composition on the upper and lower surfaces was due to the fact that bacteria commensal with algae proliferated on the upper surface but not on the lower.

河川水から分離された細菌が産生する菌体外多糖類に関する研究

In order to find new thickening agents or emulsifiers which possess uselful characteristics forfood industries, we attempted screening of microorganisms from soli and water. As a result, we found one bacterial strain which produced a large amount of extracellular polysaccharide from Sumida River in Tokyo. The strain was identified as Klebsiella pneumoniae in conformity to Bergey's Manual of Systematic Bacteriology (1984). The polysaccharide (BS-1) produced by this strain showed higher viscosity than known thickening agents such as xanthan gum, carrageenan and tragacanth gum. The viscosity of 1% (w/v) BS-1 at 20°C reached 7000cps under the shear rate of 1/S. Besides, BS-1 possessed a good property as an emulsifier. When we made emulsions of O/W=3/7 using several emulsifiers involving BS-1 and observed after 3 days of storage at room temperature, it was found that BS-1 stabilized the emulsion at the concentration of as low as 0.1% (w/v), and that the emulsion kept its creamy smoothness.

Discharge Rating Curve of the Small Rivers in Tokyo

Discharge Rating Curve of the Small Rivers in Tokyo

多摩川上流域における好気性従属栄養細菌数の季節変動とそれの環境要因との関係について

Seasonal 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.

Gas chromatographic-mass spectrometric identification of phenols and aromatic acids in river waters

The ethyl acetate extracts of water samples from two urban rivers in Tokyo were analyzed for phenols and aromatic acids by using a combined gas chromatograph-mass spectrometer after separating by solvent extraction and silica gel column chromatography. The following phenols and aromatic acids were identified: pentachlorophenol, bisphenol A, phthalic acid, trimesic acid, p-hydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, and ferulic acid. The presence of o- and m-hydroxybenzoic acids were suggested by mass fragmentography. The sources of those compounds are considered.

Measurement of the Trititium Concentration in Natural Waters

A method of routine monitoring of tritium in natural waters is described. The water sample to be assayed is electrolyzed from 6 liters a final volume of 5 ml. or less in order to enrich the tritium concentration. The radioactivity of the enriched tritium is measured with the liquid scintillation counter. The degree of tritium enrichment is estimated from the degree of deuterium enrichment, taking into consideration of the relative rate of separation facters of tritium and deuterium by electrolysis.The tritium in the rain and tap water in Osaka city in 1957. and that in the water sampled at the Tamagawa river in Tokyo were assayed with this method, and were found to be in the order of 10-1710-16 as expressed in the atom ratio of tritium to protium(T/H). Although the tritium contents in natural waters may be expected to increase with the repeated nuclear tests, it is found that at least 1000 fold enrichment of tritium is needed for measuring the tritium content in natural waters at the present level with the liquid scintillation counter.