Using Soil and Water Assessment (SWAT) Model and FLDAS and satellite datasets to Evaluate Drought Propagation for Multiple Drought Indices

The Tigris River is the second-largest river in Western Asia. The Tigris River Basin is shared by three countries: Iraq, Iran, and Turkey. Drought is a major natural disaster in almost every region of the world, causing negative impacts on water basin management. Monitoring drought and examining the principles of drought propagation are the basis for regional drought prediction and prevention. This study aims to assess drought conditions at cold and arid regions. The Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) and satellite datasets have been applied to calculate the different drought indices and reservoir areas during the study period of 1982 to 2021. Additionally, this research proposed a method combining Soil and Water Assessment Tool (SWAT) and drought indices, including Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Standardized Soil Moisture Index (SSI), and Standardized Soil Moisture Index (SVI). Our methodology could serve as a reference framework for cold and arid regions over the Tigris River Basin (TRB) and other regions of the world in understanding the spatial and temporal variability of droughts.