Although the number of fish species around the artificial beach has recovered, the number of fish is fluctuating greatly, and it is inferred that the number in East beach is restricted due to decreasing salinity. The number of species of wild birds in East beach has recovered to that before construction. The reason is considered to be because the offlimits area and relatively wide tidal flat are suitable living environments for wild birds, and it is inferred that the number of wild birds is related to the number and biomass of macrobenthos. The shore florae in East beach are situated at the reed marshland and are in the early stages of succession. The species diversity of shore florae is tending to increase.

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In analyzing infiltration into ground by using numerical models, favorable models should be characterized as a method with good convergence and good mass-balance as well as no oscillation at seepage fronts. This study compares the results obtained by finite element models for pressure-based equations and mixed-type, pressure-and-saturation-based equations with and without saturation parameterization to solve water-NAPL, two-phase flow equations with a special focus on fluid mass-balance and oscillation behavior near seepage fronts. Investigation of the accuracy of numerical results for both types of equations showed that the mixed-type, pressure-and-saturation-based equations give reliable results compared to the pressure-based equation, and the mixed-type equations with saturation parameterization give better results than those without saturation parameterization.

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This study aims to develop the river water purification system using the “SARUBOU” shell which is unused resources of a fishery processing plant. A fundamental experiment has been conducted to investigate availability of the “SARUBOU” shell as contact media and the characteristics of the water purification system by column experiment. Moreover the fundamental performance of water purification by the “SARUBOU” system is examined through comparing other media. As a result, the shell catches fine SS easily into the complex voids among the shells, and then the water quality of the purification system becomes stable. It is confirmed the “SARUBOU” shell has the suitable form that is not clogged for a long time as compared with other contact media.

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In order to develope a water purification system using the “SARUBOU” shell for practical application, this practical study was conducted on investigate the stability of processed water quality, purification characteristics, and maintenance through the field experiments in a river and a pond. As a result, it was shown that this system has a high purification efficiency and stability of removal for BOD, SS, transparency and algae as well as easy maintenance without clogging in the shell media. It was also revealed that a more suitable design of the water purification system is possible with the evaluation from a pollution load.

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In order to investigate the spatio-temporal variations of water quality on an intertidal flat which is located in eutrophicated bay, field observations of water quality have been made on Wajiro intertidal sand-flat in summer and winter. In the daytime of summer, dissolved oxygen is produced and dissolved inorganic nitrogen (DIN) and phosphate are removed from the seawater. While in the nighttime of summer, dissolved oxygen is consumed and DIN and phosphate are released from the sediment. In the winter, the absolute values of fluxes are relatively small and it doesn't show clear difference between daytime and nighttime. It is also suggested that the material exchange on intertidal flat is strongly influenced not only by the ecosystem on the intertidal flat but also by the water quality condition of adjoining offshore zone.

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A three-dimensional (3D) groundwater flow analysis system using the element-free Galerkin method (EFGM) is presented. The EFGM is a meshless method that is expected to eliminate the task of mesh generation. However, an analysis system by EFGM for complex 3D geometry has not been developed yet. In this paper, a unique mesh data called consistency-free mesh assembly (CMA) is introduced. The CMA is a simple assembly of meshes permitting incompatibility at the material interface and overlapping of meshes. This paper shows that CMA is easy to generate and use of CMA brings great advantages to EFGM. Some numerical tests are also presented to discuss the convergence of solutions and the influence of material discontinuity.

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Experiments had been conducted for investigating unsaturated water movement in incineration residue layer. Outflow responses were so rapid that they could not be expressed by Richards theory which developed for uniform porus media. Although the flux control method was adopted to measure unsaturated hydraulic conductivity of incineration residue, it was difficult to obtain the relationships between water content and flux. The results of long term continuous rainfall experiment exhibit, that water movement in incineration residue is dominated by rapid gravity flow. The power function between flux and rapidly increased water content was derived from results of flux control method. And calculation carried out by using these functions showed good agreement with observed outflow results.

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Recently, contamination of soils and groundwater is becoming a social concern in our country. Phytoremediation will be becoming one of the choices in the remediation technology. Phytoremediation is divided into four functions: phytodegradation, phytovolatilization, phytoextraction, rhizofiltration. In this paper, we tested applicability of turnip Brassica rapa for phytoextraction. Two experiments were done. The results showed that the turnip has an ability to accumulate cadmium and copper of low concentrations, like presented conditions, and that during growth, plants seemed to be less sensitive to cadmium and copper toxicity. According to the cadmium distribution, roots of turnip could extract cadmium from soils.

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Characterization of organic matter attending biodegradability is a common practice when a bio-kinetic model is used to describe the reaction rates at which organic matter of wastewater is biodegraded. However, procedures for characterizing organic matter contained in feces have not been reported yet. This paper deals with the characterization of feces; two approaches for characterizing organic matter of feces are discussed based on physicochemical determinations and biological response during aerobic degradation. Application of those procedures leaded to characterization of feces in terms of chemical oxygen demand (COD) and mass units.

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