[in Japanese]

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This study proposes to estimate an averaged hydraulic conductivity as a probability-weighted average in our geoinformation system based on adjacent water-well data. In this study, individual hydraulic conductivity of each soil/rock type was determined to obtain the least square error against field measurements in 105 pumping test locations. A basic class of 8 soil/rock types and another class of 32 types with respect to topography and geologic periods were assumed for comparison. As a result, the proposed method yielded sufficient agreements in both classes, relative to the conventional method based on simply weighted averages of the drilling records. A stepwise cross validation also determined an optimal class of 19 soil/rock types for the least prediction square error. Finally, a relation of individual hydraulic conductivities with effective thermal conductivities was shown to discuss the potential applicability of ground source heat pump systems in each soil/rock type considering groundwater advection.

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It is necessary for investigation of soil hydraulic characteristic to examine the stability of slope and bank caused by torrential rain. This study examines accuracy improvement method and effectiveness of measuring method of the field saturated hydraulic conductivity which is measured by using bore-hole in unsaturated ground from ground surface to about 10 m depth. The following conclusions were obtained.(1)It is clarified that the change of initial soil saturation degree influences the value of hydraulic conductivity.(2)It is clarified that nearly identical hydraulic conductivity could be obtained by injecting CO₂ gas for a certain amount of time before conducting the permeability test.(3)The evidence that hydraulic conductivity can be measured small than primary one of soil when bore-hole wall is stained by drilling the bore-hole is proved with comparison between permeability test before and after cleaning bore hole wall.

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BTCs (Break Through Curves) obtained with 2-dimensional reactive transport experiments in heterogeneous infiltration field were reproduced by CTRW (Continues Time Random Walk). General form and tailing of Mono-peak BTCs were well reproduced by CTRW. Parameter for the degree of anonymous dispersion，β were in the range of 0.8<β<2.0. It means obtained BTCs were close to realistic anonymous dispersion occurred in porous media. Multi-peak BTCs are corresponding to multiple flow paths. In this case, each curve should be fitting with CTRW, individually.

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