Response of Riverbed Shaping to a Flood Event in the Reach from Alar to Xinquman in the Mainstream of the Tarim River

As the largest inland river in China, the Tarim River’s flood events significantly influence its riverbed formation. This paper took the Alar to Xinquman section of the Tarim River as the study area. The study area’s digital elevation model of the river was constructed using historical Google images and Copernicus DEM 30. Six different flood events were selected, corresponding to flood events with varying sediment loads, flood volumes, and peak flow volumes. The MIKE 21 software was used to simulate and investigate the response of the riverbed shape to different flood events. The experimental findings indicate that the sand content constitutes a pivotal factor in the formation of the riverbed during flood events. Flood sediment load goes through stages linked to changes in riverbed erosion and deposition. The combination of high peak flow and bed-forming flow after the peak effectively shapes the central channel’s morphology. The fourth type of flood event had the highest sediment transport coefficient Φ among the six types of floods and caused the most significant scouring effect on the riverbed under low sediment load conditions.