With the objective to reduce negative impacts on the flora caused by underground constructions, a system is proposed, being designed in order to evaluate and to predict those influences on the flora due considerable changes of the groundwater environment. Taking seasonally fluctuations inside the groundwater household into account, the water potential under the most arid conditions among past droughts is used as a references value. On the basis of several analyses dealing with water potential inside the unsaturated zone, a technique was developed combining three-dimensional saturated-unsaturated seepage analysis and vertical one-dimensional saturated-unsaturated analysis. The system is optimized regarding accuracy of the prognosis as well as expenditure of time for these analysis. The verification based on wilting coefficient analyses around underground constructions proofed the serviceability of this system.

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Laboratory experiments using a container filled with glass beads were conducted to investigate the influence of soil water hysteresis on a saturated-unsaturated flow. Water levels of constant head tanks at the right and left boundary of the container were shifted downward first and then upward while the difference of the water levels of the tanks were kept constant. Tracer was injected at several points in the container to monitor saturated and unsaturated flow after steady states were reached at each stage. These experiments showed clear difference in the pattern of tracer trajectories governed by the soil water hysteresis. Numerical simulations including the effect of the hysteresis were also conducted to evaluate the influence of hysteresis on saturated-unsaturated flow. The simulated results matched quite well with the experiments and further were used to calculate velocity vectors and draw pathlines.

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The present study developed inversion simulation with Dusty Gas Model for molecular diffusion coefficient, Knudsen diffusion coefficient and obstruction factors. Then column experiments for dry soil mixed Toyoura sand with Bentonite were carried out in the laboratory. These parameters were gotten by using the inversion simulation developed in this study. It was found that the parameter gotten by the inversion simulation were similar to values of data published in the previous paper. Furthermore we could find the dispersivity in gas phase of soil.

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Authors have proposed an approach to evaluate deep groundwater flow separately from shallow groundwater flow, because consideration of different characteristics between deep groundwater flow and shallow one, driving force, data to evaluate the flow and temporal / space scale, is needed for the evaluation of groundwater flow system. This paper describes a methodology to evaluate groundwater flow system quantitatively with subsurface temperature data based on the degree of groundwater flow velocity. A case study is undertaken with groundwater flow and heat transport simulation for Kanto plain. The most fitted case study leads a finding that subsurface aquifer of Kanto plain is classified into upper high groundwater velocity zone and lower low velocity zone. Accordingly, the low groundwater flow zone can be separated from the targeted groundwater flow system by this method.

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