The water dynamics in unsaturated zone and the storage variation during rainfall infiltration and phreatic water evaporation were studied. The main findings are: 1) The phreatic water evaporation is greatly influenced by vegetation and unsaturated zone rock character. 2) The maximum water content variation occurs within lm from the land surface during rainfall infiltration and water content profile can be classified into four belts. 3) The rainfall infiltration recharge is greatly influenced by the existence of vegetation, groundwater depth and water storage of unsaturated zone. 4) The rainfall infiltration recharge coefficient increases with water storage of unsaturated zone and rainfall in unit groundwater depth. The lag days of rainfall infiltration increases with the groundwater depth. 5) Phreatic water evaporation coefficient is influenced by vegetation and topography. It increases with the water storage of unsaturated zone in unit groundwater depth and groundwater depth. 6) The rate of phreatic water evaporation decrease with the increases of groundwater depth and under the existence of vegetation increases with amount of phreatic water evaporation. 7) The water content dynamic in unsaturated zone goes through four stages.

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One-dimensional model is proposed to analyze non-uniform flow on the compound channel. In this model, energy slopes distribution and lateral flow effects in divided cross sections were considered for calculating mean velocities in each section. To estimate lateral flow discharge, following assumption was employed, that is, watersurface slopes were equal in all divided sections. Proposed model was applied to experimental data in comparison with previous model. As the results, it is obvious that lateral flow contributed significantly to the increase of channel resistance in non-uniform flow region.

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To analyze temporal and spatial variability of soil salinity in poor drainage area in the Hetao irrigation district of Inner Mongolia, China, measurements were made using an electromagnetic induction method (EIM) in September 2002 and in August and September 2003. During the observation periods, hydraulic gradient of ground water ranged between 1/480 and 1/1, 600 while soil hydraulic conductivity ranged 10^-5cm s^-1 and 10^-7cm s^-1, which confirmed very limited lateral flow of groundwater. Spatial variability of EC of groundwater was high, and in each well, EC remained almost constant even after large amount of leaching irrigation in 2003. Distribution pattern of soil salinity scanned by the EIM did not change greatly with total of 325mm of irrigation applied between 2002 and 2003, nor with 150mm of leaching irrigation in 2003. As a conclusion, leaching irrigation was only effective in desalinization of root zone, however spatial variability of soil salinity was difficult to reduce without discharge of salt from the field.

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The purpose of this study is to grasp living conditions of freshwater fishes and those habitats in irrigation channels of urbanizing area, to demonstrate the factors that influence habitat of freshwater fishes. This study was carried out in four seasons from December 2001 to November 2002 on Hino-channel, Ne-river, Toyoda-channel and Mukoujima-channel flowing through Hino-city. Objectives of the survey were fishes, hydraulic conditions, water qualities and physical environment of channels. In summer, juvenile and immature of Carassius carrassius subsp. 1, Misgurs anguillicaudatus and Gnathopogon elongatus appeared in large quantities at the sampling site that was located near paddy fields locally. Connections between channels and the paddy fields enabled fishes to migrate from channels to the paddy fields upward. It is suggested that the paddy fields have function of spawning and growing of juvenile and immature of fishes living in the channels. The decrease in water depth at lower of reaches has negative influence on habitat of fishes in winter.

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Nitrogen removal performance in sedimentation storage tank was investigated by using observed data on rural sewerage facility with submerged biological filters. It was found that the probability distribution of influent and effluent T-N concentration in sedimentation storage tank agree with normal distribution. The nitrogen removal was assumed to be influenced by the capability to catch suspended solids and detachment-and-elution of accumulated matter in sedimentation storage tank. Therefore, it can be thought that the nitrogen removal depends primarily on influent SS concentration, thickness of deposited sludge, and surface loading in sedimentation storage tank. The multiple regression equation, derived from observed data, shows that the nitrogen removal can be predicted by knowing three variables such as influent SS concentration, ratio to thickness of deposited sludge with water depth, and surface loading in sedimentation storage tank. As the suspended solids removal play an important role in achieving nitrogen removal of the sedimentation storage tank, the control of sludge thickness of the sedimentation storage tank is effective in maintaining stable nitrogen removal efficiency stably. The surface loading also has influence on nitrogen removal in sedimentation storage tank and the relationship between the rate of nitrogen removal and surface loading can be modeled as the form of inverse proportion.

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he morphology of small floc was analyzed to clarify the effect of turbulent mixing on the densification mechanism of coagulated floc. For this purpose, monodispersion of polystyrene latex particles under the condition of rapid coagulation was applied to the experiment. The relation between the maximum distance in the projection of formed floc, D_m, and the number of primary particles composing the floc, i, was used as a measure to evaluate the degree of the densification of floc structure. Careful comparison of this relation obtained for flocs formed only by Brownian motion with that of flocs formed in the turbulent mixing flow revealed that the densification of floc in the turbulent flow is induced even in the very initial stage of coagulation. Invoking the result of floc structure formed in laminar shear flow, we concluded that the fluctuation of fluid motion in the turbulence coupled with hydorodynamic interaction is essential to induce densification.

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It has passed in about thirty years since asphalt facing type-dam is built for the first time to our country. As for asphalt mixtures used for asphalt facing in the meantime, degradation is progressing in response to exposure, such as sunshine, rain, an ultraviolet and oxygen. This paper is research on prediction of Aged Deterioration of asphalt mixtures in facing. In this research, prediction was studied paying attention to the examination of a SHRP standard. Consequently, it is possible to DSR test and BBR test that prediction of aged deterioration of asphalt mixtures in facing.

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Citizens of Miyake Island are evacuated by Miyake volcano activity. As of 2003, main roads have been reopened. But final results of intensive investigation on damages in the agricultural area have not been reported yet. This research estimated levels of the volcanic damages of each farmland in Miyake Island by interpretation of aerial photographs with GIS on farmlands under the situation that anyone but limited groups such as governmental staffs or particular scientific researchers cannot visit Miyake Island for field survey. As a result, we found that, Igaya, western part of the island, and an area from eastern Kamitsuki to northern Tsubota had been damaged seriously, and most of the other area had been very slightly damaged. Then, some plans for revival of agriculture in each district of Miyake Island were proposed. Further more, as for the interpretation aerial photographs with GIS on farmlands, followings were found out.
1. The accuracy of interpretation of aerial photographs was improved with farmland GIS.
2. The satellite remote sensing image of high spatial resolution with an infrared band such as IKONOS image was available to read out the damages and revivals of vegetation.

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Effects of colloidal stability as functions of background electrolyte (NaCl) concentration and grain size upon the transport of colloidal particles through column packed with glass beads or aggregates of Kanuma Soil were investigated using dilute suspension of polystyrene latex (PSL). In the column packed with glass beads, the onset of discharge of PSL particles was same as that of simple electrolyte, and the value of C/C₀ (C and C₀ are the effluent and influent concentrations, respectively) of suspension decreased with increasing background electrolyte concentration over the range of 10^-4-10^-1 mol·l^-1. This behavior qualitatively agreed with the change of stability ratio of PSL particles. On the other hands, in the case of Kanuma Soil, the value of C/C₀ of suspension changed against ionic strength in the region of much lower electrolyte concentration (c.a.10^-4 mol·l^-1 NaCl). In addition, qualitatively different pattern of breakthrough curve between simple electrolyte and suspension of PSL was observed reflecting the aggregate structure of Kanuma soil. On each column, the dependence of the value of C/C₀ of suspension on ionic strength appeared clearer for the case using grains of smaller size. Under the condition of rapid coagulation, gradual and continuous decline of the value of C/C₀ with elapsed time was observed. Sedimentation of coagulated big flocs on the top layer of column was considered to explain the reason of this decline.

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Soil water repellency is closely related to soil hydrological problems such as the acceleration of soil erosion and the occurrence of fingering flow in an unsaturated soil. In order to estimate water retention of water-repellent aggregated volcanic ash soils, we obtained soil water characteristic curves (SWCCs) by using an experimental apparatus composed of a time domain reflectometry coil probe and a tensiometer. Prior to measurements of SWCCs, we investigated the dielectric property of our soil materials and results show that the dielectric property of the materials reflected the soil aggregated structure. In water-repellent materials, there was a sharp increase in water content from initial water content to full saturation with a slight increase of water pressure on the wetting processes of SWCCs. Based on the scanning curves from redrying and rewetting processes of SWCCs, it was revealed that water was firstly absorbed in intraaggregate pores rather than interaggregate pores irrespective of the degree of soil water repellency of materials. In water-repellent materials, however, water absorption in intraaggregate pores was restrained in comparison to non water-repellent materials

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In this study, the utilization of clinker ash as aggregate of concrete was investigated. Considering that both of clinker ash and fly ash possess similar chemical component, it is supposed that the clinker ash will not produce any negative effect to the concrete. Clinker ash as aggregate of concrete has high absorption. It is, thus, considered to combine it with type II or type I fly ash instead of cement to improve the consistency of concrete. Besides, addition of AE agent is recommended to make consistency better. The threshold replacement rate of fine aggregate by clinker ash is considered to be 10% while the ideal replacement rate of cement by fly ash is thought to be 30%. Though it has been clarified that replacing fine aggregate with clinker ash does not bring negative effect to the compressive strength and structure of concrete, freezing and thawing resistance will be reduced. So, addition of AE agent should be done appropriately.

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In order to compare multi-functional roles of irrigation water in Kanazawa and Shichika, the features of those irrigation waters were investigated. The results obtained are as follows:(1) Using the results obtained by the matching coefficient method from questionnaire section (1) “the purposes of present water use” and section (2) “multi-functional roles of irrigation water”, each item was classified into three categories labeled living, life-friendly and environmental water. The first category is small in Kanazawa but abundant in the Shichika District.(2) Using questionnaire above mentioned section (1), (2) and (3) “desired improvement point of irrigation water”, the relations among each item of the questionnaire shows a close relation, which means that some people evaluate the multi-functional roles of the questionnaire section item, while other people also evaluate the same item statistically with the same probability. Applying this results, a very fine relation was found between the probable expected value and the order of the mean value. The deviation of each item from the mean values was quite different between Kanazawa water and Shichika district water. The deviation was much greater in Kanazawa than in the Shichika District.

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The purposes of this report are to explain the basic characteristics of PIM-oriented Water Users' Associations (WUAs) in the large-scale irrigation districts of China. and to present their challenges. Therefore, the author collected and analyzed the articles of the case WUAs. and caught the actual condition about them from the persons concerned. As that result. basic characteristics of WUAs were found. those are 1) they are corporate bodies. 2) they have board of directors. assembly. and branch groups as their internal organizations. 3) their articles ensure the fundamental condition of democratic and autonomic organization management, 4) they manage the branch canal systems. 5) their members are water beneficiary farmers, 6) their main duties are operation and maintenance of canals, and management of water charge, etc., and their challenges were presented, those are 1) to make democratic and autonomic organization management take root, 2) to solve bad influences arising by members' decreasing, 3) to build the system which makes the intention of WUAs reflect on management of main irrigation facilities. 4) to build the system which WUAs can negotiate on about irrigation management.

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The locations of attacking flood flow banks and the way that they change, as well as the changes of the low-water route, depend on the formation patterns of alternate channel bars in river channels and the way that they change. Behaviors of alternate bars on straight channels and meandering channels which have uniform wavelengths and uniform amplitudes are studied precisely by flume experiments. However, the most important point for river channel design is to know the behaviors of regulated channels whose plan form will change in the future. The development of a method for conducting small-sized model flume experiments has been earnestly awaited, because that method would make it possible for experiments to be performed rather easily on many types of channels to be regulated in the future. In this study, it was possible to simulate the formation patterns and their changes of alternate bars on the Uetsu-Arakawa River on a small-sized model flume on a scale ofl to 1000, similarly to the way that the Oi River model experiment was performed by Kinoshita. It was possible to reproduce the behaviors of alternate bars with three different types of bed materials, the similitude law on hydraulic variables was investigated.

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A CVM analysis was employed recently by the people whose purpose was the evaluation of the multi-functional roles of irrigation water. This report first deals with the relation between the consciousness of people and the economic evaluation of multi-functional roles of Shichika Irrigation Water as a rural type irrigation water using the Turnbull and Probit CVM method. Then a second comparison of multi-functional roles was conducted for Kanazawa, an urban type irrigation water with Shichika irrigation water by the WTP cost accounting the money they would be willing to pay.
As a result of the analysis, a WTP cost was obtained of about 6, 000 yen per door per year using the Probit model, which is the between middle and higher mean value of CVM of the Turnbull model. The middle values of CVM showed about the same values in above both Probit and Turnbull models. The comparison of CVM cost between Kanazawa and Shichika irrigation water was shown to be 1, 950 yen lower in the former than in the latter case by the Probit model calculation. The reason for this difference is considered to be the structure of peoples' occupations, such as the farmer 6% in Kanazawa compared with 65% in Shichika. The reason is that the former, urban type irrigation water was mainly considered to have a role in irrigation water as a recreational function, supported by public money, while the latter was considered to be a function of irrigation water as a living measure supported by the individual farmer's own money.

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