River suspended sediment response to tropical cyclone precipitation in the Eastern United States

We leverage remotely sensed observations of suspended sediment concentration and 4km hourly precipitation observations to analyze the effect of tropical cyclone (TC) precipitation on riverine suspended sediment flux in the eastern United States. We estimate 278,500 tons of sediment were transported annually due to TCs, approximately 3% of all sediment transported (0–22% depending on location). TC precipitation transports more sediment than comparable precipitation totals attributed to non-TC events, even in cases with lower discharge. We show that TC-related sediment load is independent from upstream reservoir volume, which normally down-regulates sediment flux. Further, TCs cause rapid increases in sediment transport over a precipitation threshold, unlike comparable non-TC precipitation. Previously only observed at the catchment scale, we provide the first large-scale evidence that TC and non-TC precipitation elicit fundamentally different river sediment responses. Differences in sediment responses between TC and non-TC precipitation can inform infrastructure planning and mitigation of water quality impacts.