抄録
The necessity of rainwater storage and infiltration facilities has increased in the measures and policies regarding the sustainable water cycle in urban areas as understood by the administrative history in the last 30 years regarding rainwater storage and infiltration technology. The deterioration of the water cycle due to urbanization is expressed as reduction of base runoff, increase in total flood discharge and peak flow discharge, lack of water resources, changes in ecosystem, deterioration of water quality and change in heat environment. The promotion of rainwater storage and infiltration facilities in the residential areas is supposed to be an influential measure to remediate those problems. Therefore, it is important to make clear the effectiveness and explain to inhabitants so that they could introduce those facilities in their own houses. The physically based distributed grid model is dealt with to estimate the effectiveness of infiltration facilities for individual houses on flood discharge, usual flow discharge, groundwater level and evapotranspiration. The distributed grid model was applied for the Azuma river basin which is located in Tokorozawa-city, Saitama prefecture. Applying the model in case that infiltration facilities are promoted in the residential area of Azuma river basin, it was confirmed that the promotion of infiltration facilities in the residential areas gives a certain influence on stormwater control, usual river flow, groundwater level and evapotranspiration.
