Flash Droughts: A Local to Global Analysis of Rapid Drought Intensification and their Associated Impacts

Flash drought is characterized by the rapid intensification toward drought conditions and is primarily associated with detrimental impacts to agricultural production. Unlike conventional (slowly developing) drought, flash drought can rapidly desiccate land surface conditions in only the span of a few weeks and place excessive stress on the environment. Flash droughts form from a complex combination of thermal, moisture, and radiative flux variables, and predictability of these events remains a significant challenge due to their occurrence on subseasonal timescales. To address some of the challenges related to flash drought development and their associated impacts, the primary goals of this study were to develop an objective methodology for flash drought identification, explore the role of flash drought in socio-economic impacts, and create a global climatology of flash drought occurrence. A comprehensive methodology was developed in conjunction with the standardized evaporative stress ratio (SESR; the ratio between evapotranspiration and potential evapotranspiration) for flash drought identification. After evaluation with the satellite-derived evaporative stress index and U.S. Drought Monitor, a climatology of flash drought events and their characteristics were quantified across the United States. In addition, a case study of a flash drought event over southwestern Russia in 2010 was investigated to explore how rapid drought development resulted in cascading hydrometeorological and socioeconomic impacts. Lastly, global hotspots of flash drought occurrence were identified, revealing their frequency, seasonal timing, and spatial coverage trends with time.