1. 江河流域;河流盆地
A river basin is the area of land from which all the water flows into a particular river.

1. the entire geographical area drained by a river and its tributaries
an area characterized by all runoff being conveyed to the same outlet

e.g. flood control in the Missouri basin

Synonym: basinwatersheddrainage basincatchment areacatchment basindrainage area