A drainage basin is the area where these tributaries collect rainwater. A river with all its tributaries is called a river system.

流域是支流蓄水的区域。一条河流连同它的全部支流一起，叫做水系。

youdao

The Amazon has over a thousand tributaries feeding into it. The entire river system is the size of North America.

亚马孙河由一千多条支流汇交而成。整个水系覆盖的面积如北美洲一样大。

youdao

Yisusi river Basin has about 510 rivers and tributaries that being connected and formed one of most complex water system in the country.

沂沐泗流域有干支河流510余条，河流相通互连，是全国最复杂的水系之一。

youdao

Just 20 miles due west of the city is a 10-foot-high glacial moraine that separates the Mississippi and its vast north-south system of tributaries from the Great Lake waterways.

FORBES: A most unromantic river

The Mekong and its tributaries yield more fish than any other river system.

ECONOMIST: The Mekong river

The agreement calls for the water system to be treated as a single complex ecosystem made up of countless tributaries, underground aquifers and smaller lakes all held in the Great Lakes basin.

NPR: Governors Meet on Access to Great Lakes