Author(s): Kahhoong Kok, Wansik Yu, Lariyah Mohd Sidek, Kwansue Jung
Linked Author(s): Kahhoong Kok
Keywords: Areal reduction factor (ARF), change point test, trend test, average-point rainfall tracking method
Abstract: In this study, ARF estimations in Malaysia have been reviewed as some shortcomings were noticed in the existing technical manual. Apart from that, rainfall time series data are examined by several statistical tests to determine existence of trends and increasing trends are observed in the point of rainfalls and areal rainfalls especially for short rainfall interval. In this study, grid-based approach of Average-Point rainfall tracking method is adopted to compute the Maximum Areal Average Rainfall (MAAR). Average-Point rainfall tracking method improves the estimation of maximum areal rainfall by considering spatial and temporal distribution of a storm multilaterally. A slight increment was obtained from the ARF derived in this study when compared to the ARF presented in the existing technical manual. The increment could be explained by the changes of rainfall characteristics as concluded by the results obtained from the statistical tests done on the rainfall time series data. In conclusion, the ARF derived from this study offers the engineers or hydrologists in Malaysia with the updated information and references for storm design applications of local concerns as the outdated technical manual which was developed 30 years ago is still regarded by most of the local practitioners as the authoritative reference document
Year: 2017