The Drought Characteristics Using the First-Order Homogeneous Markov Chain of Monthly Rainfall Data in Peninsular Malaysia

摘要

Drought characteristics are important in designing the program and measures for drought mitigation and they have been used extensively by various parties in many countries. In Malaysia, the information of drought conditions and identification of drought prone areas is very limited. This study seeked to determine the drought profiles of Peninsular Malaysia using the first order homogeneous Markov chain based on Standardized Precipitation Index (SPI) of one-month time-scale. Monthly readings of rainfall data from 35 monitoring stations in Peninsular Malaysia for the period of 1970-2008 were used in the study. The procedure involved deriving the steady-state probabilities of drought events, the mean residence time for each drought category, the mean recurrence time of drought events and the mean first passage time. Analysis results showed that the longest moderate drought occurred mostly in the northwestern region of Peninsular Malaysia, while severe drought with low duration happened frequently in the middle region. The maximum duration of the severe drought condition is 2 months with majority of the severe drought areas requiring approximately 2 to 3 months to reach a non-drought condition. These results are likely to yield important insight on how to minimise the impacts of severe drought for agriculture and to avoid decadence of the water supply in areas with higher risk of severe drought. Such information would be beneficial to the agriculture planners and water resource management.