Rainfall Variability Index (RVI) analysis of dry spells in Malaysia

• Published in: Natural hazards (Dordrecht) 2022-06, Vol.112 (2), p.1423-1475
• Main Authors: Huang, Yuk Feng, Ahmed, Ali Najah, Ng, Jing Lin, Tan, Kok Weng, Kumar, Pavitra, El-Shafie, Ahmed
• Format: Article
• Language: English
• Subjects: Agricultural industry; Civil Engineering; Drought; Drought characteristics; Dry spells; Earth and Environmental Science; Earth Sciences; Environmental Management; Frequency dependence; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Hydrologic data; Natural Hazards; Original Paper; Rain; Rainfall; Rainfall data; Rainfall variability; Resource availability; Spatial analysis; Spatial distribution; Spatial variations; Water resources
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-022-05234-w

The lower number of rainfall events resulting in drier environment over the years is a crucial phenomenon attracting the concern of all around the world. The impact of rainfall deficiencies will lead to issues of water resources availability, both for the agricultural sector and also for health and human development. Therefore, this study on rainfall variability in terms of the dry spells (DS) and the drought characteristics of the regions is necessary to get a better understanding of the DS. In this study, the data period is from 1988–2017, and the intricacies of the DS and extreme DS occurrences, and spatial distribution for drought characteristics were analysed. In addition, this study was confined to the 30-year period rainfall data, which were then analysed using the Rainfall Variability Index (RVI) with two timeframes, initially, the 30-year long-term period and subsequently over six arbitrarily chosen 5-year sub-periods. The findings showed that the Northern Region and Central Region located in Peninsular Malaysia, and the regions that lie between Sabah and Sarawak had more DS occurrences in view of the higher number of DS exhibited during the study period. The next part of this study involves the spatial analysis for drought frequency (DF) and mean drought duration (MDD) over the 13 regions (4 in West Malaysia and 9 in East Malaysia) throughout Malaysia. It showed that the DF was significant for both the annual and monthly RVI, and for the MDD being significant for the monthly RVI over the 30-year period. For the six 5-year sub-periods, the spatial differences varied for both DF and MDD, are based on annual RVI.