Temporal Disaggregation of Rainfall Based on Microcanonical Cascade Model (A Software Development and Case Study)

Rain gauge stations that measure fine scale rainfall are mainly limited in number or in the length of the recorded data. Therefore, temporal disaggregation models have been considered because of their ability in generating fine scale data from coarse scale measurements of rainfall. In this study, microcanonical cascade model, which is based on the scaling properties of rainfall and constant volume of rainfall was used for the disaggregation purposes of rainfall. To this end, a software package was primarily developed based on the existing theory and then applied to rainfall data from two weather stations located in the Zanjan Province. In order to evaluate the performance of the microcanonical cascade model, comparisons were conducted between the observations and model results using some statistics including percentage of zero-values, volume of individual values, duration of events, volume of events and length of dry periods between events of rainfall. It was concluded that the use of microcanonical cascade model for disaggregation of daily rainfall to 12, 6, 3 and 1.5-hour rainfall will bring favorable results.