Synchronization of global peak river discharge since the 1980s

Abstract

Riverine floods that occur simultaneously over multiple regions often lead to amplified societal and environmental impacts compared to individual events. However, the pattern and mechanisms governing the global interconnection of peak river discharge across spatially distant and proximate locations remain largely unexplored. Here, on the basis of a global annual peak discharge database from 4,407 observational hydrometric stations, we identify hubs for remotely linked discharge peaks spanning thousands of kilometres. We show increasing trends in the number of remotely linked watersheds and the total drainage area, pointing to amplified synchronization of global peak river discharge since the 1980s. Ocean–atmosphere oscillations, through the perturbation of both temperature and precipitation anomalies, dictate the global coupling pattern and temporal evolution of discharge peaks. Our findings highlight an emergent profile of global peak river flow in a warming climate that can benefit coordinated flood risk management. River floods that occur simultaneously in multiple locations can lead to higher damages than individual events. Here, the authors show that the likelihood of concurrent high river discharge has increased over the last decades.