Assessing the role of drought in dust storm formation in the Tigris and Euphrates basin.

Drought is a common meteorological phenomenon and one of the world's most costly natural hazards. A large part of the Tigris and Euphrates basin (TEB) is located in the arid and semi-arid regions of western Asia and suffers from drought. Drought has many destructive effects on the environment and human societies, among which the formation of dust storms, is a major global challenge. This study aims to figure out the role of different types of drought on dust storm formation in the TEB. Standardized precipitation index (SPI), Tasseled Cap greenness index, and surface water area changes based on time series of satellite remote sensing data were considered as proxies to investigate meteorological, agricultural, and hydrological droughts, respectively. Our results show that the continuation of the 5-month and 27-month meteorological droughts are followed by agricultural and hydrological droughts, respectively. In recent decades, the TEB has experienced two prominent drought periods in 2008-2012 and 2021-2022, resulting in a 214 % and 200 % increase in dust events, respectively, compared to the 23-year (2000-2022) average. Overall, 84 %, 10 %, and 6 % of the TEB dust events can be attributed to meteorological, agricultural, and hydrological droughts, respectively.