抄録
Using geographic information system (GIS), the Kawagoe region in Japan was examined in the case in respect of the possibility of the rain water utilization in the region. Using the minute numerical information that land use of the every 10 meter mesh was recorded in 15 classification, rate of outflow, infiltration and reservation of rain water in every land use were calculated on the basis of building coverage ratio and literature data of discharge coefficient in two cases in the case in which the rain water tank is not founded and case in which it is installed. In addition, by dividing the Kawagoe region into 238 meshes in the 1km four every quarters, from totaling of each mesh of the land use point number, rate of outflow, infiltration and reservation of the every mesh were calculated. In the Kawagoe region, by the introduction of the rain water tank, the result showed that runoff control and utilization of the rain water for 48.7 million cubic meter/year (35.6% of outflow rate and 15.3% of all precipitation) were possible. Still, in this study, all rain water which fell in the roof was able to be stored, and again, all stored rain water was able to be utilized, they were calculated. In the future, it is necessary to carry out the detailed examination considering a size of the rain water tank and application of the rain water utilization, a balance of rain water infiltration and rain water utilization.
