When every drop counts

Brazil rainfall

With Brazil just coming out of a severe drought that has affected many areas of the country over the past two years, it was timely that Associate Professor Joseph Awange from the Department of Spatial Sciences at Curtin University and his team of national and international researchers undertook research to study drought and rainfall patterns in that country.

The first part of the study analysed the long-term sequence of drought events in Brazil based on monthly rainfall between 1901 and 2013.

In the study, approximately 25 km x 25 km grids were derived from the monthly rainfall data at four timescales (short: 3-month and 6-month; medium to long: 12-month and 24-month).  Subsequently, the probability of drought occurrences, intensity, duration and areal-extent were calculated.

One of the main conclusions of this study is that probabilities of extreme droughts are 1 in 9 over northern Brazil, and 1 in 12 over southern Brazil, respectively.  In general, no evidence of significant trend is detected in drought frequency, intensity, and duration over the last 11 decades at all four time-scales.

The results of the study are reported in the Science of the Total Environment. The study is a recommended read by the editors (editors’ choice for Science of the Total Environment) and can be accessed for free from the Editor’s choice collection until 31 December 2016.

Joseph intends to return to Brazil in January 2017 where his research group will continue to look at long term rainfall trends and the geological characteristics of the Brazilian aquifers.

As Joseph explained, “It’s hoped the long-term analysis on drought/rainfall patterns as well as the meteorological factors driving the level of rainfall will be helpful in providing guidance on policy formulation and management of drought impacts in Brazil, i.e., within the concept of living with drought.”