The water had raced down the slope and scoured out the bed of a stream.

水顺着山坡流下来，冲刷出一条小河道。

《牛津词典》

There was a little stream that went by down the slope, making a constant murmuring.

有一条小溪流下斜坡，发出不间断的呢喃声。

youdao

The sand content in the water flux affects the down stream sand and with less impact when the slope is long.

坡面水流含沙量对坡面产沙有一定的影响，随坡长越大影响力越小。

youdao

Without a sense of scale, every slope was magnified and stream rivulets resembled gorges.

BBC: The quietest place in the US