Flood-driven transport of sediment, particulate organic matter, and nutrients from the Po River watershed to the Mediterranean Sea

•The event-dominated transport accounts for one-third of the annual particulate export.•The region where the sediment is sourced effects transit time and flux of sediment.•Sediment loads simply based on sediment rating curves can give rise to large errors.•Nitrate in the river drops due to the dilution of the baseflow with rainfall waters.•Concentrations of nitrite and ammonia are driven by the particulate in suspension.