Network dynamics reveal drought synchronization hubs in the Po River Basin

The intensifying climate crisis has exacerbated the frequency and severity of prolonged droughts, particularly in environmentally and socio-economically vulnerable climate change hot-spot regions. Despite advancements in monitoring, the spatiotemporal propagation and interdependencies of drought events remain poorly understood. This study analyzes drought synchronization within the Po River Basin, a critical hydrological system contributing approximately 40% of Italy's GDP. Using the 12-month Standardized Precipitation Index (SPI-12) and complex network methods, we reveal the spatiotemporal dynamics of drought propagation, identifying key hubs and hot-spot regions. Our analysis identifies spatial hubs where droughts originate and terminal zones where impacts converge. This process follows a diffusive propagation mechanism, whereby local events spread through preferential pathways until they are interrupted by seasonal climatic conditions that restore precipitation regime. These findings enhance understanding of drought dynamics in interconnected systems, advancing the application of complex network theory to hydro-climatology. They also provide a foundation for research on societal resilience to climate change and the development of adaptive strategies for sustainable hydrological systems.