Refers to the upper part of a river or stream. Can be used as a noun or with の to modify another noun.
その川の上流にはダムがある。
There is a dam in the upper reaches of the river.
上流地域では大雨が続いている。
Heavy rain continues in the upstream area.
noun, noun which may take the genitive case particle 'no'
Refers to the upper echelons of society, often in terms of wealth or status. Antonym: 下流 (lower classes).
Antonyms: 下流
彼女は上流階級の出身だ。
She comes from an upper-class family.
上流社会のマナーを学ぶ。
Learn the manners of high society.
The upper reaches of this river have beautiful scenery.
He comes from an upper-class background and is very polite.
They surveyed the water quality from upstream to downstream.
upper class; the elite