Why is the Ganges River sediment fan in the Bay of Bengal so large?

The sediment fan of the Ganges River in the Bay of Bengal is the widest and thickest in the world primarily due to the immense volume of material transported by the Ganges-Brahmaputra river system.1

This river system carries a combined suspended sediment load of approximately 1.84 billion tons per year, which is the highest in the world. These terrigenous deposits are derived largely from the Himalayas and the Indian subcontinent. Over millions of years, this massive influx of sediment has been deposited into the bay, creating a vast delta and a deep-sea fan that serves as the seaward prolongation of these river valleys.231