Abstract
Due to climate change, extreme rainfall and drought events are becoming more and more frequent in several regions of the globe. We investigated the suitability of employing statistical and fractal (or scaling) methods to characterise extreme precipitation and drought events. The case of the island of Mauritius was considered, for which monthly mean rainfall data for the period January 1950 to December 2016 were analysed. The generalised extreme value distribution was used to extract the 10- and 20-year return levels and the Standardised Precipitation Index (SPI) was used to identify anomalous wet and dry events. A log-term correlation analysis was also performed to characterise the relationship between maximum rainfall and its duration. The results indicate that the 10-year return level is approximately between 500 mm and 850 mm and the 20-year return level is between 600 mm and 1000 mm. Results also show that the extreme maximum rainfall events occur mostly during austral summer (November to April) and could be related to the effects of tropical cyclones and La Niña events, while anomalous dry events were found to be significantly persistent with very long periods of drought. Moreover, there was a strong correlation between maximum rainfall and its duration. The methodology used in this work could be very useful in similar studies for other Small Island Developing States.Significance: We show the usefulness of both statistical and fractal methods to understand occurrences of extreme precipitation events. We identify anomalous wet and dry events in rainfall time-series data using the Standardised Precipitation Index.
Highlights
Recent events occurring worldwide, such as the global heat record in 2016, major flood events in different parts of the world, the rapid melting of glaciers and sea level rise, among others, are reminders that the climate is changing more rapidly than in preceding centuries
The results show that the extreme maximum rainfall events are more prone to occur during austral summer seasons (November–April) as it is during this season that there are more cyclonic activities in the South West Indian Ocean region
We have presented the analysis of return levels in extreme rainfall events occurring in Mauritius during the period 1950–2016
Summary
Recent events occurring worldwide, such as the global heat record in 2016, major flood events in different parts of the world, the rapid melting of glaciers and sea level rise, among others, are reminders that the climate is changing more rapidly than in preceding centuries. Among the various natural disasters which affect humankind, heavy rainfall and long periods of drought have been reported to be detrimental to the environment, with disastrous consequences on the ecosystem, agriculture, and infrastructure as well as on the people facing such extremes.[1] For instance, in 2012, people in the central and western USA had to live in abnormally dry conditions due to persistent heat waves This calamity put the health and safety of these people at risk and caused more than USD30 billion in damages.[2] Heavy rainfall can contribute to flash floods, resulting in water accumulation in flood prone areas, which is very dangerous. The year 2018 marked the occurrence of several deadly flash floods such as those in India, France and Vietnam, which caused several casualties.[3,4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
