Two methodologies for valuing non-market benefits (the travel cost method and the contingent valuation method) are briefly described. Both are then applied to estimating outdoor recreation benefits derived by visitors to the Lake Teganuma on the outskirts of the Tokyo metropolitan area. Using the travel cost method, a trip generating function is first estimated. The trip generating function is then used to estimate consumer surplus. The contingent valuation method is also applied to estimate the visitors' maximum willingness to pay (WTP) to preserve the Lake. Results, in terms of outdoor recreational benefit estimates, are presented for each method and compared each other.

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This study sets up and introduces innovative methods for classification of rural areas which have desolated fields. Furthermore, this study discusses the effect of principal factors on the desolated fields.
Two methods were employed for classification of settlements; first, principal component analysis (PCA) method, and second, fuzzy clustering method. One hundred and five settlements were selected from large rural areas with progressively desolated fields in Japan and were classified by using those two methods. The study showed that road pavement and land reclamation should be considered as the most important factors in land use planning in order to avoid field desolation.
The classification done by PCA method for desolated fields could not reflect the effect of synthesized factors. On the other hand, fuzzy classification done by the synthesized factors can represent the social effects. It was proved from the classification results that fuzzy classification can be used for practical purposes. Moreover, sensuous expression technique-Characteristic Radar chart was proposed. These methods are practically useful to express the settlement characteristics of classified groups.

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A production rule table may be defined as an ordinary table where the fuzzy levels for two conditional (if) parts of production rules are placed in the X and Y-axes and the corresponding fuzzy levels of inference (then) part are placed inside the table. Determination of the fuzzy levels of the inference (then) part corresponding to the fuzzy levels of the conditional (if) part is very complicated if it is done by simple trial and error method. Hence, this study refers to develop a method for optimization of production rule table and to use it in a fuzzy inference model. This optimization method involves four parameters to express the nature of the curvature presented by production rule table in a three-dimensional plane to make agreement between observed and calculated values. This optimization technique was applied in the model developed by Hasan et al. to determine the intake-flow size of irrigation water of headworks. Optimization of production rule table was found to be very easy to determine the fuzzy levels for inference (then) part of the production rule in a fuzzy inference model.

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Recently, the increase of abandoned farmland is becoming one of the major problems from the view of farmland conservation. Furthermore, it isn't only the problem within mountainous area but also within suburban area. In this study, the authors examine the characteristics of the abandonment of cultivation in suburban area and the agricultural factors of abandoned farmland, and propose some preventive measures. Senshu region, in Osaka Prefecture, has been urbanized as bedroom suburbs since the 1980's.
Using Quantification Theory Type I, in this paper, we examine why farmers stop cultivating their farmland and make a comparison of the processes to the abandonment of cultivation between Senshu region and Chutan region, in Kyoto Prefecture, which is one of the mountainous areas.
Through this analysis the followings were found out. First, the farming communities which are close to Osaka City or surrounded with mountains have the high ratio of abandoned farmland to total farmland. Secondly, in Senshu region, the occurrence rate of abandoned to total farmland is related to decrease of cultivated acreage and the rate of land under perennial crops to total farmland. In this region, however, decrease of farm households controls the increase of abandoned farmland exceptionally. The reason is that most of the farmers in the villages where the number of farm households is decreasing run greenhouse horticulture or have small farming scale which can be cultivated by themselves. In Chutan region, the causes of occurrence of abandoned farmland are similar to in the suburban area.
To deal with the problem, we consider the land consolidation to be necessary. Also the establishment of the contract farming among several villages should be effective to cover labor shortage.

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The purpose of this study is to find out characteristics of abandonment of cultivation in suburban area and to propose some preventive measures. In this paper, the authors examine the agricultural land use in eight agricultural communities in Kaidzuka and Kishiwada city, in Osaka Prefecture. And the questionnaire surveys were conducted to consider characteristics of farmers who tend to abandon their farmland.
From the agricultural land use point of view, the following tendencies were found out.
1) In Urbanization Promotion Area, the farmlands facing roads are abandoned and are from place to place.
2) In the valley, majority of farmlands which are far from the farmer's residence are abandoned.
3) Most of the small farming plots or the farmlands which don't receive enough sunlight aren't cultivated.
From the questionnaire survey, the farmers who have Japanese orange orchards or small scale farmers, who don't have successors, and now cultivating for their own food supply tend to abandon their farmland. On the contrary, the farmers who run greenhouse horticulture and having their own personal customers cultivate most of their farmland.
In conclusion, we propose the followings to prevent farmland from abandonment. In Urbanization Promotion Area, there have been high demands for allotments among urban residents and actually, some farmers expect their farmland to be used as allotment. Therefore there should be supports from the administration and the agricultural cooperatives to manage allotment. In the plain, the land consolidation is necessary for conservation of prime farmland, and also establishment of contract farming is indispensable to cover labor shortage. Finally, in mountainous area, farmers need more stable income from agriculture. Accordingly, for example, the direct delivery system between farmers and customers or tourist farming, which makes use of regional resources, should be necessary.

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Recently, there is a problem that rice plant growth and yield are not stable in large-sized and direct sowed paddy fields. So in this paper, the authors studied about “appropriate establishment density” and “appropriate quantity of seeding” for direct sowing by examinating the relationships between establishment density and rice plant growth and yield in paddy fields which was direct sowed by broadcasting in flooded puddy field.
The result is that; It is clear that rice plant growth and yield are likely to be stabilized in more than 100 plants/m² and so this establishment density is defined as “appropriate establishment density”, and to obtain this establishment density we shall seed more than 4 kg/10 a, and which is called “appropriate quantity of seeding.”
Secondly, the reasons for decision of establishment density of direct sowing are classified into 3 groups; heterogeneity of seeding density by limitation of ability of direct sowing machine, influence upon rate of germination and early plant growth at whole fields by climate condition, and site-specific germination and early plant growth loss by field condition such as levelling. And improvement of field condition is necessary and suitable way to obtain establishment density of direct sowing.

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Microstructure near freezing front was observed with a microscope during soil freezing to clarify frost heave mechanism. Pore ice as suggested by Miller was not observed. Frost heave amount depended on freezing velocity rather than temperature gradient. Super cooling degree at ice growth surface determined frost hearving rate. The temperature at which ice lens started to grow decreased with increasing the freezing velocity. These results can not be explainted by the frozen fringe model. Frost heave could be predicted in terms of the super cooling degree.

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In this paper, using the normal variables which are transformed from the time concentration of a rainfall based on the annual maximum 24-hours rainfall depth, a method is proposed to estimate the annual maximum 1 hour rainfall depth. Comparing the observed annual maximum 1-hour rainfall depth and the estimated one, we proposed two equations and discussed how to obtain the normal variable and how to determine its upper and lower limit values in order to estimate the annual maximum 1-hour rainfall depth. Methods are much different from the former studies on the point of view for obtaining the annual maximum 1-hour rainfall depth.
Utilizing the estimated annual maximum 1-hour rainfall depth, it is possible to estimate the return period of probable one. Estimated cumulative probability distributions have reproduced any of the observed one with quite good agreement. To utilize this method, however, it is necessary to know the statistical parameters in advance. Then, provided the annual maximum 24-hours rainfall depth for any district in Japan, it is possible to estimate the annual maximum 1-hour rainfall depth without the observed one.

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For the purpose of conserving prime agricultural land, we proposed “the agricultural land use management unit” as a rural land use planning unit area.
To conserve the quantity and the quality of prime agricultural land for a long time, it is necessary that the agricultural land is conditioned suitably for the land readjustment. Besides in order to be able to go into effect the land readjustment project in the unit in the future, agricultural land must be fitly formed for “the road removing contour oriented field system.” And the boundary of the unit must be drawn to keep the inner field's condition suitable for the field system.
The unit area's various creative functions on regional development were also investigated. Especially discussed functions were the exclusive ones against conversion of farm land to non-farm uses, that lead the land use constructively to order. Based on these functions, we proposed methods of planning and management of agricultural area's land use.

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The changes of soil physical properties in abandoned terrace paddies are discussed. An experimental abandoned paddy was selected in a hilly mountainous area in Niigata Prefecture. A neighboring cultivated paddy was also investigated as a control to the abandoned one. Investigations were carried out for three years including the abnormal drought in 1994.
At the surface layer of the abandoned plot, the soil, initially characterized by high water content, low bulk density and few macropores, turned to be dry and highly porous just after the drought. During the following two years, macropores increased once more but then decreased. At the subsurface of the abandoned plot, macropores did not increase as much as in the surface layer after the drought, but hydraulic conductivity increased and remained high. These changes could partially be explained by the process of shrinkage and swelling, but the factors affecting the condition of the. field were so complicated that the whole mechanism could not be explained. By the influence of such changes in soils, surface runoff measured at the outlet of the paddy extremely decreased after the drought. This means infiltration of water into the soil increased significantly after the drought.
Soils in the cultivated plot shrank more than that in the abandoned plot during the drought, and large cracks developed. But the field was tilled and puddled so well after the harvest that farming has been done without any trouble afterward.
From the investigation of some other abandoned paddies, such influences of drought were found to be much more severe in paddies which had been ill-drained. It is noticeable that the hydrological characteristics of abandoned paddies such as ill-drained or well-drained are changeable due to the meteorological conditions. This conclusion is important for examining the problem of land conservation in hilly mountainous paddy areas.

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An improved finite element model was developed for analysis of irrigation pipeline systems. A submain flow equation was provided to express the relationship between the inlet discharge and inlet pressure head of a submain and to allow the submain with multiple branches to be considered as a large emitter located on the main. The pressure distributions along mains are obtained first. The discharges and inlet pressure heads of branches along each submain are then determined using the forward step method because the inlet pressure head and discharge of the submain are already known. The nodal arrangement was rationally simplified. It does not required to input the initial estimates of nodal pressure heads when analyzing a pipeline system with single reservoir. When analyzing a pipeline system with multiple reservoirs, it is very easy to input the initial estimates of nodal pressure heads because the number of nodes is reduced very much. This method is very suitable for hydraulic analysis in management of rotationally operated systems using personal computer. The procedure is accurate, simple, and fast.

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The theory of super low frequency response analysis is applied for designing the regulating capacity of intermediate reservoir and farm reservoirs in large branching pipeline systems. Daily water consumption that changes with a basic period of 24 hours is used.
Step function is adopted as the water consumption pattern for each farm reservoir. The function is a safe side approximation of the water consumption pattern.
Results obtained from the synchronous system inputs (simultaneous patterns) and those from the nonsynchronous (patterns having time lags) are compared.
Step function inputs to the system are shown to have general characteristics as compared to the mean water consumption pattern obtained from actual data from a farmland.

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In most practical cases, e. g., water and waste water treatment, coagulation of colloidal particles is carried out in turbulent flows. However, it is difficult to evaluate flow field in turbulent flow, so coagulation processes in turbulent flows are not sufficiently analyzed. In the present study, we investigated the rate of coagulation in turbulent flow in rapid coagulation systems where all collisions lead to coagulation, that is, coagulation rate depends on collision rate which is determined by relative motions of particles by Brownian motion and turbulent fluid motion. In the theoretical part, the rate equation proposed in the previous investigations was modified. To confirm this model, we measured the rate of coagulation with monodispersed polystyrene latex spheres (1.00μm diameter) in the Rushton type stirred tank (both the inside diameter and the height of the tank were 0.13 m) filled with about 1.17 M KCl solution. The changes of particle number concentration, N (t), with time were measured by means of Coulter counter. Experiments were carried out over wide range of turbulent intensities expressed as energy input rate per unit mass (from 7.2×10^-5 to 0.58 m²s^-3). Experimental results showed good agreement with the calculated values by our modified model. It was also found that the coagulation of rather later stage, i.e., N (t)/N (0) =0.14, is predictable by the extrapolation of the initial stage.

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A multi-leveled density flow model was made in order to estimate the effect of the submerged structure for upwelling in a stratified flow field and applied to the upwelling induced by the structure. The validity of the numerical model was shown by comparison with the results of hydraulic model experiments. Using this model, the three-dimensional hydraulic system around the structure has been revealed. The oncoming flow impinges on the structure and then the water which impinges on the upper half of the structure flows over it ( “surmounting flow”); while the water at the lower half passes around the edge of the structure. The surmounting flow raises the interface around the structure, which then creates a gradient of interface in the horizontal plane. The resultant density gradient changes the direction of the surmounting flow into the horizontal direction at the interface. Then the water flows outward, induced by the effect of the density gradient as the water flows downstream. To compensate for this, the bottom water flowing around the structure horizontally converges in the wake and then upwells. This upwelling is not strong enough to break through the interface, but it will transport the nutrients up to the interface.
About the effect of the structure for generating upwelling, the essential following two points were made clear. 1) The three amounts (the maximum height of interface, the area of cross section between deformed interface and initial interface, and the cross section area of the transition layer), increases as internal Froude number increases, and reaches a plateau at a certain value of the internal Froude number. 2) The maximum height of the interface appears at the center of the structure; and the height decreases gradually as it approaches the edge of the structure and decreases sharply as it leaves the structure.

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Agricultural land has four different prices: Valuational Price of the Fixed Property Tax, Valuational Price of the Inheritance Tax, Investment Price of the Land for Permanent Agricultural Use and Market Price. As Agricultural Infrastructure Improvement and Rural Development has deep relation to agricultural land price, it is proposed what tasks should be hereinafter performed by Agricultural Infrastructure Improvement and Rural Development, in addition to that Standard of Agricultural Land Evaluation does not correspond to today's Agricultural Infrastructure Improvement and Rural Development Engineering, and that Mobilization of Agricultural Land, Converted Substitute Lot and Public Functions of Agricultural Land should be properly evaluated in Agricultural Land Price. To propose positively that Standard of Agricultural Land Evaluation determined with standards of other Ministries and Agencies should evaluate properly the Agricultural Infrastructure and Rural Development Engineering is one of the means to clarify the significance of Agricultural Infrastructure Improvement and Rural Development including proposing questions about the Agricultural Basic Act.

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Usually, for the purpose of effective water use, so called buffer pond is installed at the site where open channel system linked to pipeline system. In this paper, we propose practical control procedures for the amount of water supply at intake in such compound type of canal system.
The capacity of buffer pond considered is designed according to estimation procedures proposed by Yoshino. The effective use of buffer pond is realized by supplying water at intake so as to correspond to shortage of total storage in both buffer pond and open channel, provided that water use in pipelines are limited planning outflow discharge. Then, observed information of outflow discharge from pond to pipelines or water level in a pond at each operation time intervals are required for the controlling flow condition at intake. Practical operational method at intake with the help of information at buffer pond are examined for two types of layout of inlet at buffer ponds. Proposed control procedures are confirmed with an unsteady flow simulation model of flow in compound type of canal.

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