Correlation between meteorological and climatological drought and agricultural stress in the Middle Euphrates River Basin

The Middle Euphrates Region is a crucial area for investigating the effects of climatic change on vegetation, as it is a hot spot of climate change, and it holds vital agricultural importance for Syria. This research focuses on understanding the intricate relationships between precipitation, vegetation health (VH), and drought in this region. The Standardized Precipitation Index (SPI) and the standardized Vegetation Health Index (s(VHI)) were employed to quantify these interconnections. Collected data for the period 1983–2017 were: (a) annual precipitation data of 14-gauge stations from the Syrian Ministry of Agriculture, (b) monthly gridded precipitation estimates from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), and (c) weekly Vegetation Health Indices from the NOAA Center for Satellite Applications and Research (STAR). The series of SPI and s(VHI) evidenced the recent documented events of drought and vegetation stress. The correlation analysis of SPI and s(VHI) revealed a positive and statistically significant correlation, both at meteorological and climatological time scales. Therefore, the study unveiled that the annual vegetation health is sensitive to both meteorological and climatological droughts, thus shedding light on the complex interplay between various environmental factors in the Middle Euphrates Region. Our study, while focusing on drought detection and the interplay between precipitation, vegetation health, and drought, suggests that understanding these relationships, particularly through multi-year precipitation data, can offer valuable insights for enhancing drought assessment using empirical or machine learning approaches.