Suspended Sediment Pulses and Sediment‐Discharge Relationships in Earthquake‐Affected Rivers Along the Tibetan Plateau Margins

Large earthquakes along the Tibetan Plateau margins trigger widespread landslides that deliver substantial sediment to river networks, driving intense and long‐lasting landscape change. However, identifying and modeling the fluvial sediment responses to large earthquakes remains challenging. In this study, we develop an earthquake‐affected sediment transport model that couples fluvial transport with time‐varying sediment supply, using multi‐year time series of suspended sediment concentration (SSC) and flow discharge ( Q ) from three rivers affected by the 2008 Mw 7.9 Wenchuan, 2017 Mw 6.4 Nyingchi, and 2017 Mw 6.5 Jiuzhaigou earthquakes. The model represents enhanced sediment supply by seismic landslide inputs and rainfall‐driven mass movement, and fluvial transport by Q ‐based transport capacity and channel sediment scouring and deposition. The results show that incorporating dynamic supply terms is indispensable to reproduce post‐seismic SSC pulses and complex SSC– Q hysteresis. The proposed model explains 78%–90% of long‐term SSC variance and outperforms traditional rating‐curve approaches by 7%–74%. The model framework may have particular relevance for understanding the role of large, long‐lasting seismic landslides in regulating post‐seismic sediment regimes for other earthquake‐affected regions.