Clustering and Trend Analysis of Global Extreme Droughts from 1900 to 2014.

Drought is one of the most devastating environmental disasters. Analyzing historical changes in climate extremes is critical for mitigating its adverse impacts in the future. In the present study, the spatial and temporal characteristics of the global severe droughts using Palmer Drought Intensity Index (PDSI) from 1900 to 2014 are explored. K-means clustering is implemented to partition the extreme negative PDSI values. The global extreme droughts magnitude around the world from 1950 to 1980 were less intense compared to the other decades. In 2012, the largest areas around the world, especially Canada, experienced their most severe historical droughts. Results show that the most recent extreme droughts occurred in some regions such as the North of Canada, central regions of the US, Southwest of Europe and Southeast Asia. We found that after 1980, the spatial extent of the regions that experienced extreme drought have increased substantially.