2007 Volume 12 Issue 2 Pages 23-28
A mathematical model is proposed to describe spatio-temporal distribution of rainfall intensity. The model is a simple drift equation, which is a partial differential equation including drift terms. The coefficients of the drift equation are assumed to be constant in a storm event and are identified from observed rainfall data. The identification procedure uses a correlation analytic approach. In order to examine validity of the model, three observation networks have been set up since September 2005. Each observation network consists of three high resolution tipping-bucket raingauges with data loggers. The distance between two raingauge stations in an observation network varies from 824 m to 9,693 m. One of the observation networks is located in the temperate zone of Japan, while other two are in the coastal savanna zone and in the Guinea savanna zone of Ghana. The results of identification well represent local characteristics of rainfall distribution. Furthermore, it is suggested that reconstruction of spatio-temporally distributed rainfall data from the identified coefficients is prerequisite for advanced researches into runoff analysis, flood forecasting, and rainwater harvesting.
