World drought frequency, duration, and severity for 1951-2010

In the context of climate change characterized by rising temperature and more extreme precipitation regimes, drought is one of most relevant natural disasters. This paper presents maps of global drought frequency, duration, and severity for the periods 1951-70, 1971-90, and 1991-2010, to give an overview of the respective drought hot spots. Drought frequency is defined as the number of drought events occurred, drought duration as the number of months in drought conditions, and drought severity as the sum of the integral area below zero of each event. Because drought is mainly driven by rainfall deficits, we chose the Standardized Precipitation Index (SPI) as the base indicator to derive drought-related quantities. SPI-12 has been calculated on a monthly basis using a Gamma distribution fitted to a 60-year baseline period (1951-2010). Global grids (0.5˚ x 0.5˚) of the Full Data Reanalysis Version 6.0 dataset provided by the Global Precipitation Climatology Centre (GPCC) have been used as precipitation data input. The regions most exposed to prolonged and severe droughts during 1951-70 were the Central U.S.A., the Argentinian Pampas, Russia, and Central Australia; during 1971-90 they were Southern Chile, the Sahel, and Siberia; during 1991-2010 they were the Amazon Forest, the Congo River basin, Mongolia and North Eastern China, and Borneo. A linear trend analysis between 1951 and 2010 shows that, globally, a small increase in each drought component is observed. The increase in drought duration and severity is found to be more significant than the increase in drought frequency, in particular in Africa, Eastern Asia, the Mediterranean region, and Southern Australia, whilst the Americas and Russia shows a decrease in the drought components.

SPINONI Jonathan;  NAUMANN Gustavo;  CARRÃO Hugo;  BARBOSA FERREIRA Paulo;  VOGT Juergen; 

2014-01-10

WILEY-BLACKWELL

JRC83588

0899-8418,   

http://onlinelibrary.wiley.com/doi/10.1002/joc.3875/abstract,    https://publications.jrc.ec.europa.eu/repository/handle/JRC83588,   

10.1002/joc.3875,