Why is navigation on the Yellow River in Gansu limited?

Navigation on the Huang He (Yellow River) within Gansu province is limited primarily due to the river's significant silting and its highly variable seasonal flow.1

The river carries the highest concentration of sediment of any river in the world, which contributes to the instability of the riverbed and creates challenging conditions for navigation. Additionally, the river experiences considerable seasonal fluctuations in volume, which further restricts its utility for transport. Consequently, navigation on the Huang He is effectively restricted to the specific section between Lanzhou and Zhongwei.231