The purpose is to show the procedure and basic concept of determine the normal flow discharge of rivers from landscape point of view. The process model of landscape recognition was proposed and the discharge image test of rivers was conducted using 42 rivers' pictures to 215 local officials. The result indicated 1) ‘SUIRYOU KAN’ means image of amount of water flow 2) Image of water flow width and image of water depth have strong relationship between ‘SUIRYOU KAN’. 3) W and B were defined average of visual angle of water surface width and visual angle of width of river during 1°-5° of depressed angle. W/B explained the image of water flow width.

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The experimental rainwater recycling system has been constructed and we have researched its performance. In this system, purified water is supplied into the rainwater tank when the volume of stored rainwater for miscellaneous use is insufficient. The consumption of the purified water used for miscellaneous use is varied with the way of purified water supply. The way that consumes very little purified water for miscellaneous use is; 1)supply of the purified water into the tank starts when the volume of stored rainwater is less than the volume of water for miscellaneous use in two days, 2)volume of the supplied water is equal to the volume of water for miscellaneous use in a day. If the rainwater recycling system is introduced every office building which number of the floors is less than 10, the volume of purified water for miscellaneous use decreases approximately 30%.

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Effects of aeration intensity and distance between membranes on sludge accumulation process in the suction filtration of activated sludge suspension was investigated using directly immersed flat sheet membranes. It was shown that sludge accumulation in steady state, rate of sludge accumulation and sludge accumulation starting time can describe the sludge accumulation process. And dependency of them on the experimental conditions was investigated. It was shown that sludge accumulation in steady state and rate of sludge accumulation are mainly under the influence of the shear stress on membrane surface, and sludge accumulation starting time is under the influence of distance of membranes and blowing intensity. Further, it was investigated that the dependency of viscous sublayer on the sludge accumulation stariting time, and based on this, a relationship that can describe the sludge accumulation starting time is proposed.

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Various new types of pavement materials have been developed for pedestrian precincts. It is necessary to investigate pavement materials for pedestrian precinct considering pedestrians safety and comfort for an aging society. Administration of construction is also studying adjustment of pavement at sidewalks from a point of view described above. This report treats thermal characteristics of pavement materials which is one of factors influencing pedestrians comfort. It investigates thermal characteristics of pavement material by applying a core-shell model of human temperature regulation and a rational temperature index.

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Aiming at an evaluation of intertemporal and interspatial transitions of the salinization problem, five different irrigation strategies at the Illi river basin in Kazakhstan are planned. Net future benefit produced by each alternative is estimated and is compared to the others by computer simulation. The simulation is composed of a grossagricultural-profit-estimation module, a salinity-damage-estimation module, and a net-future-benefit-estimation module. As a conclusion, it is shown that the down stream transition of salinization is not desirable. Demonstrating intertemporal transition, the model is also designed to show quantitative trends of the net present value as a function of the social time preference and the evaluation period.

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This paper discussed the characteristics of urban environmental systems with comprehensive regard to the following four (4) related elements: water, solid-waste, energy and information. The author analyzed the planning process for the total arrangement of the system in recent 40-year-long urban development operation by Housing and Urban Development Corp. (HUDC). Herein, it was recognized that the coordinating measures by HUDC for financial/institutional supplement have been crucial to complete the total system arrangement; partly contributing to enhancement of beneficiary-pay-concept and thus leading to future environment-friendly system creation.

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The improvement of biological activity on biological activated carbon (BAC) were investigated using denitrifying fluidized bed reactors. Saccharose were used as a source of organic carbon. To estimate the effect of adsorption capacity of media on denitrification activity, artificial light aggregate (ALA) was used as a non-adsorptive media. There were no significant difference between BAC and ALA in nitrate and nitrite reduction rate of suspended biomass and detached biofilm from media. But the nitrate and nitrite reduction rates of attached biomass on BAC were 1.64 and 1.45 times higher than those of ALA, though there are not a significant differences between BAC and ALA in attached biomass and number of denitrifying bacteria. These results indicate that bio-activity of attached biomass on BAC were improved by adsorption capacity of BAC.

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Based on vertical distribution of the pesticides in a reservoir, quantitative evaluation of pesticides residues originated from paddy field application were investigated in this study. Runoff loadings of herbicides, which were mefenacet, thiobencarb and daimron, into the reservoir were 138g, 29.8g and 54.7g, respectively. The spatial distribution of pesticides in thermally stratified water clearly show that concentrations of the pesticides residues were same levels as in the inlet part of the reservoir. The dominant residues of the pesticides (ca. 50-60%) were present in the middle water layer accompained with temporal distribution in the reservoir. The inflowed mefenacet may be remaining and degrading in the middle layer of R. Reservoir. The average first-order rate constant for mefenacet is 0.003d^-1 for the observed period. The results of the study indicate that spatial monitoring as well as periodical monitoring is essential for the accurate evaluation of the pesticide residues in the lake and reservoir water.

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A field observation was pertormed within and above a street canyon along a route 246 in summer 1996, to investigate the characteristics of heat balance of street canyon including the effect of transportation, and also to verify the forcing effect of vertical momentum exchange due to transportation. The following results were obtained; 1) anthropogenic heat due to transportation reached more than 200 (W/m²), 2) temporal change of sensible heat was strongly affected by not only net radiation but also anthropogenic heat due to transportation, 3) latent heat was not negligible, 4) scintillation meter was available for measuring the sensible heat from street canyon, and 5) transportation gave the horizontal momentum to the surrounding atmosphere in the same direction as the traffic, so that the wind velocity and the vertical momentum exchange were modified by transportation especially in rush hours.

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