A Study on the Simulation of Hourly Precipitation Series

In the calculation of R value included in the universal soil loss equation, the data of hourly precipitation is needed, and more accurate R values will be obtained by the analysis using the long term precipitation data. Most of the meteorological observatories in Japan do not have sufficiently long records of hourly precipitation to obtain accurate R values. There is some research on the simulation of daily precipitation, but very little on hourly precipitation, and the objective of this paper is put the emphasis on the simulation of hourly precipitation. The authors found the initial probability, transision probability of hourly precipitation and the number of consecutive dry days by using the hourly precipitation data for 30 years from the Simonoseki Local Meteorological Observatory, and then tried the generation of hourly precipitation data dependent on the assumption of time-independent process and autoregressive process. We obtained good simulated hourly precipitation of the natural rainfall in the months, like Feburuary, with less rainfall.