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CR prepress abstract   -  DOI: https://doi.org/10.3354/cr01703

Spatiotemporal characterization of meteorological drought: a global approach using the Drought Exceedance Probablity Index

Natalia Limones*, Jesús Vargas Molina, Pilar Paneque Salgado

*Corresponding author:

ABSTRACT: The objective of this research is to present a global spatiotemporal characterization of meteorological droughts using historical precipitation data through the Drought Exceedance Probability Index (DEPI). As a novelty, the relationship between the meteorological drought characteristics and the monthly precipitation at a global level is explored. This contributes to delve into the drought features observed in the different areas of the planet, which can help anticipating the behavior of future droughts. DEPI was applied to the Climate Research Unit global gridded high-resolution rainfall dataset covering the period 1901-2019. The monthly drought index series were examined to extract the number of droughts experienced in each pixel of the globe and their durations, intensities and severities. Results show agreement with other global drought characterization efforts, revealing the areas with a greater drought occurrence. This paper demonstrates that regions with less seasonality and less intra and inter-annual rainfall variability report fewer drought episodes. Duration and severity of drought are also related to these rainfall features. The last part of the study provides a portrayal of the temporal distribution of droughts in the world. The study concludes that regions with many events show a stable even distribution over time, but many pixels in the intertropical regions, the Middle East and smaller patches in Mongolia, China, Siberia and Canada show currently higher intensity and longer duration drought events than in the beginning of the twentieth century, while the opposite occurs in patches in Scandinavia, Russia, Argentina or Tanzania. The analysis demonstrates that DEPI is easy to use, it works in different climates, and it is effective to detect the onset, end and intensity of drought.