Abstract: Bed-forming discharge is an important index characterizing the erosion and deposition of river beds, and is also a key parameter for river management. Based on measured data from 1960 to 2019, we calculated and analyzed the bed-forming discharge at four hydrological stations, namely, Shizuishan, Bayangol, Sanhuhekou, and Toudaoguai, using the improved Makaviev method, bank-full level method, and geomorphology work method. In 1960-1989 and 2010-2019, the bed-forming discharge ranged between 2 100 m³/s and 3 540 m³/s, indicating medium scouring, while in 1990-2009, the bed-forming discharge was 740-1300 m³/s, reflecting severe deposition. In spatial scale, bed-forming discharge was larger in the upper reach stations compared to the lower reach stations. Bed-forming discharge is significantly influenced by the amount of incoming water. When the water inflow during flood season is less than 10.5 billion m³, properly increasing the inflow by jointly dispatching the three reservoirs in Liujiaxia, Longyangxia, and Haibowan during flood season could appropriately augment bed-forming in the Inner Mongolia reach of the Yellow River. Results manifest that the physical meaning of the improved Makaviev method is clear and the calculation results are relatively reasonable.The research results provide important implications for determining the alluvial river bed-forming flow and channel management in the Inner Mongolia reach of the Yellow River.

Key words: bed-forming discharge, riverbed evolution, improved Makaviev method, bank-full level method, gemorphology work method, Inner Mongolia reach of Yellow River