HSK 7-9
流域
liúyù名
river basin; valley; drainage area
这条河的整个流域都在降雨。
Zhètiáo hé de zhěnggè liúyù dōu zài jiàngyǔ.
Rain is falling across the entire basin of this river.
Say it
Hold the button, say it, then let go.
Other HSK words sharing a character
Also free:
Appears across levels (7-9) in the HSK 3.0 word list.