河床

1. Origins, structure, and basic meaning

• Structure: 河床 is read as かしょう and is a noun for the bed or bottom over which a river flows.
• Basic usage: Stones on the riverbed appear in 河床の石, while changes after heavy rain appear in 河床の変化.

2. Common pitfalls and similar expressions

• The bottom terrain of a river
  • It is the bottom beneath the flowing water where stones and sediment lie and shift, not the water surface or riverbank.
• Difference from 川底
  • The meanings are close, but this term is more technical and suits surveys, civil engineering, and geographic description.