The saturated magnetization (σ) and density (ρ) of the ferrite sludge formed by two-step treatment of wastewater containing heavy metal (nickel sulfate) and citric acid were measured over a wide concentration range of citric acid. Simultaneously, the concentration of nickel and iron ions in treated water was measured. From the results of measurement, the effect of the two-step treatment on the parameters above listed was quantitatively discussed by comparing the three different process treatments: ordinary, excess-iron and two-step treatments. The σ-C_cit (concentration of citric acid) curves for three different treatments shift along C_cit axis with the order of ordinary, excess-iron and two-step treatment. The ferrite sludge formed by ordinary treatment was reformed to the sludge available for industrial utilization by two-step treatment. The concentrations of nickel and iron ions in treated water after two-step treatment were lower than that in treated water produced by ordinary or excess-iron treatments. The two-step treatment is favorable for steady operation of the ferrite process, industrial utilization of the sludge and good quality of the treated water.

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The characteristics of sets of local environmental indicators/indices in Japan wereanalyzed by comparing with international, national, and local environmental and sustainability indicators/indices in the world. We investigated indicators/indicesdeveloped by 47 international organizations, national and local governments and NGOs. There were clear differences in the selection of indicators/indices between Japanese sets and those in other countries. As a result from Hayashi's quantification method 3 using 44 organizations and 60 environmental themes, selection of themes by organizations was explained by 2 axes: the first axis was Local/Global and second was Physical/Social. These sets werecategorized into 4 groups by projecting them on these axes. Group A, that is more Global and neutral on the second axis, includes UNCSD, UNEP, etc. Group B, more Physical and neutral on the first axis, includes SCOPE, Netherlands, etc. Group C, more Social and neutral on the second axis, includes Seattle, Hamilton-Wentworth, etc. Most of indicators/indices in Japan, represented by Urban Environmental Quality Indices developed in mid-1980 s by Kita-Kyusyu City and Tokyo Metropolitan Govern ment, belong to Group D, which is distinguished from other three groups by more?g Local?h position on the first axis. Those developed recently for basic environment planin several prefectures also belong to group D, but they are shifting to more ?hGlobal?hdirection. It seems they tend to select global environment themes as well as local ones. There are a few exceptions which belong to Group A (Adachi Ward) and B (Miyagi Pref.). There is no example in Group C, because this group is not covered by environmentalindicators but by social indicators in Japan. On the other hand, we analyzed selection of indicators/indices according to?g Driving force?h and ?gPressure?h(D/P), ?gState?h and ?gEffect?h(S/E), ?gResponse?h(R) framework. We found 4 types: Type I of high D/P ratio, including Netherlands, WRI, etc. Type II of high S/E ratio, including SCPOE, EEA, etc. Type III of high R ratio, including indicators/indices developed in Japan. Type II Wis characterized by balancedselection from D/P, S/E, and R, including DECD, EPA, etc. Before 1992 most of Japanese indicators/indices belong to type I a.?@ After 1992, those which developedindices for presenting total environmental pressures belong to type I, the others whichselectedindicators for setting targets of policy measures and monitoring their compliances belong to type III.

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The continuous monitoring of the atmospheric CH4 concentration has been performed in the campus of Nagoya University, and multivariate analysis was applied to the data including the monitoring data obtained at the 7 observatory stations of Nagoya City during 1991-1995. Cluster analysis was used for the analysis of the kineticbehaviors of CH4 in urban atmosphere of Nagoya. When correlation coefficientsamong the data at the 8 stations were implemented for the measure of similarity, Nagoya City was divided mainly into two groups of urban and suburban areas. Then, when Euclidean distance metric was also applied to the same data set, the Nagoya University and Higashisakura station belonged to one cluster, where the CH4 concentrations had been kept at the higher concentration. Furthermore, time series analysiswas applied to the CH4 concentrations observed at the Nagoya University for 1991-1996, where a digital filtering technique employing the fast Fourier transform and low-pass filter was used for smoothing the data. The growth rate variations showed the slowing down in 1992 and from 1993 to 1995. Finally the CH₄ out-flux in Nagoya Cityarea was estimated as 2.0-2.7 tCH4 km^-2 yr^-1 from the mass balance of CH₄ .

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The partial pressure of carbon dioxide (pCO₂ ) in river water was measured. The pCO₂ showed well defined diurnal variations characterized by the low values in the daylight hours, and high values in the nighttime. The amplitude of daily pCO₂ ranged from 500 to 1200 ppm. Assuming that the respiration rates of biota and the advectionof carbon dioxide in river water are nearly constant all the day, the pCO₂ can bealtered by three processes; carbon dioxide exchange across air and water interface, water temperature change, and biological consumption of carbon dioxide in water through photosynthesis. The relative magnitudes of all processes were evaluated. The effects of first two processes on diurnal variations of pCO₂ were about 30 to 60 ppm. These values are negligibly small compared with the real diurnal variation of pCO₂ . Taking into account the relationship between dissolved carbon dioxide and oxygen, weconcluded that the photosynthesis by water plants was the most important term to determine the diurnal variation of pCO₂ . The pCO₂ showed a maximum in warmermonths (ca. 1000 ppm), and a minimum in colder months (ca. 350 ppm).

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This is a proporsal of a method for the environmental impact assessment concerned with the vegetation, which may be effective to estimate the degradation of ability of vegetations caused by land-development on the view points of their functionsfor environmental conservation (FEC) and also their naturalness degrees (ND). The both amounts of FEC before and after land-development are counted as the total of individual amounts calculated based on the area read on the vegetation map, evalutatepoint of FEC (5 ranks) and relative importance of FEC (5 ranks) of each vegetation planned for development. Also, both ND amounts before and after development arecalculated from the area and evaluated point of ND (10 ranks) of each vegetation. The difference between amounts before and after development indicates the value of degradation and the rate of the difference against the value before development gives the ratio of degradation caused by the land-development. As the definite examples, to which this method applied, two plans of ski courses were presented.

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It has been reported that the δ¹³C of C₃ plants changes with various environmentalstresses. In order to obtain baseline data for the assessment of environmental stresses in declining Japanese cedar (Cryptomeria japonica) in the Kanto Plain, Japan, I comparedthe δ¹³C variations with the height of needle position in the crown between declining and healthy trees. The results showed higher δ¹³C ratio in needles (1-year-old) from the upper crown of declining trees than that of healthy trees. There was no significant difference in the nutrient levels of needles and in the SO₂ and 0₃ levels between the declining and healthy sites studied. Thus, nutrient levels and air pollution stress probably had little or no effect on the δ¹³C of needles. On the other hand, the atmo spheric water vapor saturation deficit was higher in declining areas, and Japanese cedar has the relatively low water stress tolerance. In addition, the vertical changes of δ¹³C in the crown were negatively correlated with those of twig volume (defined as an average volume of 1-year-old twigs at each position) probably caused by the reductionin leaf enlargement due to water stress. These results suggest that the δ¹³C of needles from the upper crown of declining trees is strongly affected by stomatal closure relatedto water stress.

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