Quantitative Study on Flow-Driving Factors in the Lower Yellow River Bankfull Discharge Based on MIC-RF

This study employs a two-stage Maximum Information Coefficient-Random Forest (MIC-RF) model based on discharge, sediment concentration, sediment transport rate, and sediment grain size data from four hydrological stations in the lower reaches of the Yellow River between 1960 and 2022. The model quantifies the contribution of various factors to the interannual variation in bankfull discharge.Results indicate that peak flood discharge (importance 0.300) and Annual Runoff Volume (0.272) are the dominant factors; Maximum sediment transport rate (0.135), median grain size of suspended sediment (0.126), and sediment Inflow Coefficient (0.122) exert indirect influence by regulating the sediment transport-deposition balance; Bed Sediment Median Grain Size (0.045) has a negligible effect. These findings provide quantitative basis for maintaining main channel flow capacity and optimizing water-sediment management.