Identifying Rainfall Pattern in Sabah and Labuan, Malaysia

The rainfall pattern particularly affects the on the environmental conditions, dryness and wetness, as well as the human activities. In Malaysia, the wetness and dryness condition have been recorded to lead to more serious natural disaster such as flood and drought that could cause loss of life. In this study, rainfall characteristic of the mean rainfall amount per day is concerned and will be fitted using the smoothing technique of Fourier series to identify the rainfall patterns over the easternmost state of Malaysia, Sabah and Federal Territory of Labuan. In order to achieve the objective, the daily rainfall data from three stations namely; Sandakan, Kota Kinabalu and Labuan are studied. The parameters of the Fourier series was estimated using the Generalized Linear Model, while its performance was assessed through the analysis of deviance. The results showed that, the two harmonics are required in modeling the mean rainfall amount per rainy day for the three stations. The two harmonics are best described with the unimodal rainfall pattern. The analysis found that the maximum rainfall amount received for the station in Sandakan was recorded in December and October and November for Kota Kinabalu and Labuan stations respectively. Meanwhile, the driest month was in April at the Sandakan station, February at Kota Kinabalu station and March at Labuan station.