Multifractal Properties of Temporal Rainfall Series in Peninsular Malaysia

Abstract

Studies on the investigation of scale-invariance of rainfall are still in the early development stage in the humid tropical regions. In order to further enhance understanding of the rainfall variability across a range of temporal scales in these regions, this study aims to investigate and characterize rainfall in a multifractal framework from areas in Peninsular Malaysia. It is done by studying the scaling of the statistical properties of rainfall. Data set consisting of 15 min rainfall observations from 56 rain gauge stations were adopted and the stations were grouped into four regions to identify the possibility that the multifractal properties of rainfall could depend on the geographical locations and local climatology. The results show that the temporal structure of rainfall in Peninsular Malaysia displays a multifractal behaviour for scales ranging from 15 min to about 3 days. The multifractal parameters that described the scaling properties of rainfall in terms of intermittency and multifractality revealed to be different for each region in the peninsula, particularly between the west and east coasts. The rainfall process for east coast was characterized by less intermittent rain with the rainfall fluctuations displaying a strong degree of multifractality. While for the west coast which consists of northwest, west and southwest regions, they exhibited a similar distribution of rainfall occurrences which is very intermittent and unsmoothed. Rainfall fluctuations, however, were spikier in northwest regions than in the west and southwest regions.