The outputs of 29 Global Climate Model (GCM) are adjusted to per nearly 80km square called primary area partition for the Standard Grid Square. The datasets are used to analyze monthly precipitation and temperature in seven typical basins in Japan. Evaluated with AMeDAS observation, MRI-AGCM outputs have high resolution and they are proved to have better reproducibility. Regarding GCM outputs belonging to CMIP3 with coarse resolution of more than 100km, the reproducibility of each individual GCM is worse but the multi-GCM ensemble shows improvement of reproducibility. At the same time, there are no clear differences between CMP3 and MRI-AGCM outputs as for the change calculated from present and future climate predictions. This shows that high reproducibility would not lead directly to reducing uncertainty of estimating future climate change. On the basis of these results, practical usage of GCM outputs with observation data is considered for hydrological analysis.

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 A simulation model was formulated to assess underground space inundation in the event of a large-scale flood due to a failure of a levee along the Ara River. Data on locations and structures of flood defense facilities such as frame barriers and flood gates at entrances and exits of subway stations or other underground spaces were included in the model. Conditions at connecting spaces at junction stations were also incorporated in the model. Both surface flow and tube flow simulations were integrated into the model. The results of the simulation indicated the following: 1) wide underground areas will be submerged by the tube flows spreading through connecting spaces at junction stations; 2) tube flows will reach central areas including Tokyo Station faster than surface flows: 3) if a levee failure occurs at Senju in Adachi-ward, a wide area including the central part of Tokyo will be inundated, although the surface flows will be limited to a smaller area; and 4) in some simulation cases, measures to block flood waters at openings such as entrances would effectively work to decrease the length of the submerged areas of tubes as well as to delay the spread of the inundation.

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 Turbulence and DO measurements were conducted in laboratory flume, in which two kinds of bed conditions were chosen, i.e., smooth and vegetation roughness conditions. It was found that the vegetation promotes the gas transfer beneath air/water interface, because a larger surface velocity divergence is induced by a large-scale shear vortex formed in the vegetation edge. Further, we revealed a great dependency of the gas transfer on the vegetation density. Based on the measured results, a new surface divergence model was developed which can predict successfully the gas transfer velocity in the openchannel flows for the both of the smooth and vegetated bed conditions.

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