Spatiotemporal analysis of lower tail precipitation events over the Eastern Middle East using the complex network to capture drought patterns

Iran and the countries around it.‎ Precipitation deficits, particularly lower tail precipitation events (LTPEs), are a critical driver of drought; nevertheless, their spatiotemporal dynamics remain insufficiently examined. This study investigates LTPEs in Iran using a complex network (CN) framework, employing 30 years (1994–2023) of monthly precipitation data from the Climate Prediction Center. The 10th percentile criterion was employed to identify LTPEs, followed by event synchronization to assess connectivity. Undirected and directed complex networks were established to assess degree centrality, betweenness centrality, clustering coefficient, mean synchronized distance, network divergence, and directional fluxes. The results of all undirected coefficients indicate that Saudi Arabia, southeastern Iran, and Pakistan suffer from severe drought, revealing localized ‎drought clusters in these zones, highly vulnerable to the reduction of LTPEs. The mean synchronized distance (MSD) ‎reveals that eastern, central, and western Iran are substantially impacted by localized droughts, while ‎increased MSD values in Saudi Arabia, southeastern Iran, and Pakistan imply a heightened risk of extensive drought ‎propagation to other zones. In addition, the results of directed coefficients reveal Saudi Arabia and Turkmenistan as critical pathways ‎for drought propagation. The CN approach effectively illustrates the synchronization, distribution, and ‎directional spread of drought based on LTPEs, providing novel insights into drought dynamics in a particularly ‎vulnerable area.‎ • Complex networks reveal spatiotemporal dynamics of precipitation and drought ‎in Iran.‎ • Event synchronization applied to 30 years of precipitation data identifies Lower ‎Tail Precipitation Events (LTPEs).‎ • Key drought sinks: Western and far northwestern Iran, Isfahan, east of Iraq. • Key drought sources: the N, central, southeastern regions of Iran, southwestern Turkmenistan, & Pakistan.‎ • Findings improve drought monitoring, transboundary managing, and ‎preparedness rely on spatiotemporal raifall analysis.‎