In land improvement business plan design criterion "pipeline", it has be made that pressure of water hammer is analyzed numerically with the principle in order to calculate the design water pressure. However, the standard waterhummer analysis program does not exist until now. In the future, it is important to do the maintenance management of pressure of water hammer analysis program of which the reliability is high in the community between engineers of the society level in order to ensure hydrology function of the pipeline system. It is necessary to model various and ancillary facilities for the maintenance management of the waterhummer analysis program. Then, maintenance management method based on object orientation development process was proposed in order to reduce the labor burden of the maintenance management in expanding the code shared in the community. By that method, it is expected that engineers continuously shares the standard program without the masking at the society level.

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The basic data management method was proposed in order to carry out numerical analysis by reading XML documents which describe information of the irrigation pipeline. Concretely, the concept of the irrigation pipeline was regulated by RELAX in order to describe information in XML documents, and the classes of object oriented language Java which could handle information equal to these regulations were constructed automatically by Relaxer. The numerical analysis program could input information in the XML described with the via of objects which were created based on these classes documents as a data. By using this data management method, the labor of data input work was reduced, when engineers reexamined hydraulic function of irrigation pipeline by mading to combine some hydrology units, because the file of each hydrology unit already made in the design can be recycled.

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Improving cultivation management to reduce environmental loads, such as emission of greenhouse gases, are pressing tasks for the sustainable development of paddy field farming in the Asia monsoon region. From this viewpoint, it is important to predict nitrogen and carbon dynamics associated with changes in soil redox status under various water management regimes. Recent studies have demonstrated the effects of dissolved oxygen in infiltration water on the redox potential and nitrogen and carbon dynamics of soils. Therefore, in this study, we investigated the effect of air penetration from the soil surface on the soil redox potential profile by performing a column evaporation experiment using a paddy soil. During evaporation, the soil redox potential increased from the surface downward due to the penetration of small amounts of air. The onset of redox potential increments was slower than the air penetration front, in deeper layers or at higher evaporation rates, and the contribution of penetrated air to the soil oxidation state is considerably greater than that of dissolved oxygen in the soil water column.

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Return flow and repeated use of irrigation water for paddy is the most important issue in Asian monsoon region because the water sometimes applied more than evapotranspiration plus percolation. New return flow analysis, replacement in order method, is proposed for main canal which aimed to the dual-purpose of irrigation and drainage. The method contains unique numbering procedure for irrigation and drainage system. After calculation of return flow from the drainage block, the block replace in order from small to large number as the same of the irrigation system. Through this replacement, the return flow to the receive weirs can be systematically conducted. This method applied to the Shichika irrigation district when water right discharge, resulting the return flow ratio is 59% for entire area, in which 33% is available for irrigation again in the area and the other 26% does not available, because the return flow discharged directly into the downstream canal which have no receive weir or the Japan Sea.

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In this paper, we clarified how the government policy on decontamination measure of radioactive material treats rural areas of Fukushima by scrutinizing zoning and priority criteria established by the national government for the decontamination work. The priority criteria were established by the government to deal with decontamination work in an effective manner by considering radioactive material concentration level, population density and public facilities of contaminated areas. The result of our analysis suggests that, however, it would structurally cause delay of decontamination work in rural areas which are often sparsely populated with less public facilities. Such delay would be exacerbated by obstacles in consensus building among stakeholders for decontamination work and lack of storage sites for contaminated soil and materials. Also, contaminated areas with high radioactive material concentration level would face another obstacle, the limit of decontamination work. All of these would prolong the evacuation of residents, which would be likely to decrease the number of those who return to their old home. To cope with these difficulties, we proposed that the municipal government of Fukushima should formulate district-scale reconstruction plan to carry out decontamination work and reconstruction of public facilities.

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Phenolphthalein method is utilized as the general diagnosis method on neutralization of concrete. However, this method cannot satisfy to indicate the soundness of reinforced concrete. In this research, the applicability of phenolphthalein method to the specific evaluation and prediction of neutralization was evaluated through the analytical and the experimental method. As a result, analytical estimation using image processing on pH distribution of cement hydrates was possible by multiple indicators: two concentrations of phenolphthalein solution and 0.4 % concentration of tropaeolin O solution. It was also clarified that visual inspection method using two types of indicator (1.0 % concentration of phenolphthalein solution and 0.4 % concentration of tropaeolin O solution) can give sufficient and accurate information about the relationship between the discolored pH and its depth from surface of concrete. Finally, new evaluation method was proposed for specific evaluation on neutralization of concrete considering the remaining neutralization time.

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Japan has 210,000 earth-fill dams and many of them are located in the Hyogo prefecture. These earth-fill dams were constructed over a long period of history, and damaged by earthquakes and typhoons. However, under reconstruction, there is a problem which is lack of suitable soil material for the core zone. Further, old earth-fill dams have large deposit of muddy soil.
In this paper, a method of creation of improved soil for impermeable core zone was proposed. The method was used some materials that should be recycled, for example muddy soil and old banking material. It is necessary to be said that the material is not only low cost but also mechanically stability and environmentally-friendly. In the laboratory, unconfined compression test and permeability test were conducted to clarify the best mixture fraction, and availability of quicklime and fly ash. Additionally, the field test was conducted. A large soil mixing machine was used to blend these materials, and it was tested for practical applicability since the improved soil for the impermeable core zone needs to be homogeneously-mixed. As the result of laboratory and field experiments, the improved soil made of muddy soil and old banking material had sufficient strength and impermeability. It was suggested that the improved soil could be reused when earth-fill dams were reconstructed.

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The actual hunting area and ranges of hunting activities of hunters using guns and hounds are clarified and the contribution of these hunting activities on the establishment of a forest-farmland buffer zone is examined. In this study, a hunting group from a suburban area in Ehime Prefecture, targeting Japanese wild boar is examined. The landscape factors affecting hunters travelling distance is also studied. As a result, the hunting group in this study focused their activities on narrow, 600 m-wide bands around settlement. In such cases, a habitat management effect peculiar to hunting with guns and hounds can also be expected, as it keeps wildlife away from settlements and in the process generates a buffer zone along farmland peripheries. The study also shows that the burden of movement on hunters is closely related to the elevation, road conditions and degree of farmland clustering of the hunting zones.

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A newly developed flood inundation simulation model targeting to low-lying agricultural watersheds adopted Topographically Adjusted Cells (TAC) to calculate floodwater movement. The TAC is characterized by irregular shaped polygonal cells which are bounded by linear structures such as roads or elevation gaps. These features result in higher calculation efficiency and reproducibility through the avoidance of unnecessary numerical grid allocation and having the linear boundaries possess elevation values. Despite these advantages, the simulation model with TAC has not been widely used due to the cost in terms of labor and time involved in the acquisition and arrangement of the geometric attribute of the cells. To overcome these technical hurdles, we developed a method to create TAC using GIS functions and to prepare complex geometric attribute data with calculation algorisms. This paper introduces the labor and time-saving method to arrange TAC based on the example of watershed model that the we developed.

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In Mekong river basin, population increase and rapid economical growth may cause the water pollution problem in the future. In this study, a liner regression model was developed by using annual nutrient load and spatial statistic data from GIS analysis. Estimated units of nutrient pollution loading of forest, agricultural land, human and cattle represented the characteristics of Mekong river basin such as agricultural level, lifestyle, waste water treatment, livestock intensity, and compared with literature values of Japan. The result of effluent ratio from each pollution factors at five observation stations showed that nutrient load from human and agricultural land were more dominant in downstream area. Then, spatial distribution of nutrients load on 1km grid resolution was calculated from estimated unit of nutrient pollution loading.

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