THE RAINFALL FOR THE FLOOD CONTROL PROJECT IN URBAN AREA

Abstract

In urban areas, since intense land use is remarkable and improvement of rivers and sewers and reinforcement of drainage capability are very difficult, storage facilities, which perform momentary storage of a flood, such as a regulation pond and a storage pipe, play an important role. The present projects for rivers and sewers are made based on each design scale and design hydrograph, and the present condition is that mutual adjustment and increase in efficiency are not attained. DAD analyses of time-spatial scales (approximately 10-180 minutes and up to about 100km²⁾ for small rivers and sewer basins are performed. Moreover, the difference in the rainfall characteristics by the rain factors (typhoon and thunderstorm) is clarified, and the way that should be as external force of the project, which can reflect these characteristics, is arranged.