A SIMPLE SCALING CHARATERISTICS OF RAINFALL IN TIME AND SPACE TO DERIVE INTENSITY DURATION FREQUENCY RELATIONSHIPS

Abstract

The properties of time and space scale invariance of rainfall are investigated and applied to Intensity-Duration-Frequency (IDF) relationships. The hypothesis of the simple scaling is examined in time and space in Yodo River basin and the simple scaling properties in time are confirmed, which is used to derive IDF relationships for short-duration rainfall of several hours from the statistical characteristics of daily data only. The derived IDF matches well with the one derived from historical observed data. Also, the simple scaling properties in space are examined. It is found that two ranges less than 1000 km 2 and more than 1000 km 2 show different scale properties.